PNG/MNG Construction Set – Reference

REFERENCE

PNG/MNG Construction Set embodies a great deal of functionality for creating and manipulating transparent and animated PNG and MNG files. It's unlikely that you'll find uses for absolutely everything PNG/MNG Construction Set knows how to do. It's more unlikely still that you'll want to try to learn everything there is to know about PNG/MNG Construction Set in a single session.

This document is an encyclopedic reference for all the functions of PNG/MNG Construction Set.

If you have not already done so, please read the Tutorial and Quick Start documents installed with PNG/MNG Construction Set. They will walk you through the basic operation of the software and provide you with step by step procedures for performing the most common tasks that PNG/MNG Construction Set is called upon to do.

Note that throughout this document you will encounter references to configuring PNG/MNG Construction Set and using the Setup dialog. The configuration options and the Setup dialog are discussed in detail elsewhere in this document.

Index:

- About
- Animated Cursors (ANI Files)
- Animation Wizard
- Anti-alias
- Banners
- Buttons
- Chunk Types
- Closing
- Color Selection
- Color and Balance
- Combine
- Creating a New File
- Crop
- Copying, Cutting, Moving and Pasting Chunks
- Deleting
- Depopulate
- Drag and Drop
- Exporting to Animated GIF
- Exporting to SWF (Macromedia Flash™)
- Extract
- Flip and Rotate
- Frame
- Hardware and Software Requirements
- Header Chunks
- Image Chunks
- Image Strip
- Inserting
- LED Signs
- Manage
- Merge
- MNG to PNG
- Movies
- Opening and Saving Files
- Overlay
- Paint
- Palettes
- Print
- Properties
- Protection Matrix
- Reconstruct
- Resize
- Reverse
- Setup
- Shadow
- Spin
- Status Panel Animated Signs
- Supercompressor
- System Information
- Text Chunks
- Themes
- Tile
- Tool Bar
- Transitions
- Transparency
- Underlay
- Undo
- Upgrade Manager
- View

About

Select About from the Help menu to see the About dialog for PNG/MNG Construction Set. If you're evaluating an unregistered copy of PNG/MNG Construction Set, you will no doubt be familiar with this dialog. It's worth noting that it will not appear when you exit a registered copy of PNG/MNG Construction Set, nor will it talk.

The About dialog will tell you which version of PNG/MNG Construction Set you're presently using, including the patch number if there is one. This information is important if you have cause to contact us with a bug report or a question about the software.

Note that this dialog has a secret screen which can be activated by clicking on one of the objects in the background graphic.

Animated Cursors (ANI Files)

Windows allows for its conventional still cursors to be replaced with animated cursors, as stored in the ANI file format. Unlike conventional still cursors, animated cursors can move, jump, revolve, dance, spin, rotate, vibrate, mutate, undulate and change colors faster than a liberal politician facing a room full of reporters.

PNG/MNG Construction Set can import ANI files to MNG animations, and export MNG animation to ANI files for use as cursors. It's worth keeping in mind, however, that ANI and MNG files aren't perfectly interchangeable – the issues surrounding the differences between them will be discussed in a moment.

On most Windows systems, animated cursors are stored in a folder named C:\Windows\Cursors. If you peek therein, you should find a selection of ANI files.

To import an ANI file into PNG/MNG Construction Set, select Import from the File menu, and then select Import from ANI. A File Open dialog will appear. Select the ANI file you're interested in and it will open in a PNG/MNG Construction Set document window a few seconds later.

Most contemporary ANI cursors will import into PNG/MNG Construction Set as 32-bit animations, with alpha-channel transparency.

Exporting

To export a MNG animation to an ANI cursor, select Export from the File menu of PNG/MNG Construction Set, and then select Export to ANI. A File Save dialog will appear.

You'll note that in addition to the conventional regalia of a Windows File Save dialog, this one includes fields named Hot Spot X and Hot Spot Y. These values will determine the hot spot for the cursor you're about to create, the point relative to the upper left corner of your cursor where Windows will consider your mouse to actually have been clicked. As such, if you set the Hot Spot X and Hot Spot Y values to zero, you'd have to place the upper left corner of your cursor over whatever you wanted to click on when you stomp your left mouse button. In a conventional arrow cursor, the hot spot is set to the point of the arrow.

Set these fields appropriate to the design of your cursor.

One of the aforementioned differences between the way ANI cursors and MNG animations work is the way they represent the time between frames. MNG animations measure time in 1/1000ths of one second. ANI cursors measure time in 1/60th of one second. In that 60 doesn't divide evenly into 1000, and as neither format knows what to do with a fraction of a time unit, converting between them will always be something of an approximation.

The speed of your MNG animations, as they play in PNG/MNG Construction Set, will probably turn out to differ from that your animated cursors when Windows finally gets to display them. Some experimentation may be called for to get the results you're looking for in this regard.

Using ANI Cursors

While animated cursors can be built into Windows applications, should you happen to be writing one, most users of ANI files will want to apply them to the task of customizing their Windows desktops. You can use ANI cursors to replace the standard Windows cursors.

You can store your custom cursors anywhere on your hard drive. Alternately, you might want to add them to Windows' existing store of custom cursors – doing so will make them slightly easier to find when you actually want to use one.

To add your custom ANI cursors to Windows existing cursors, you'll need to locate the folder where Windows stores its cursors. This will usually be C:\Windows\Cursors. In the event that your installation of Windows stores them elsewhere, you can track them down with the Windows Search function – look for *.ANI, and see where the default animated cursors installed by Windows are hiding.

To apply a custom ANI cursor to Windows:

1. Open the Control Panel
2. Double-click on the Mouse applet.
3. Click on the Pointers tab.
4. Select the cursor you'd like to replace with your ANI cursor from the Customize list and click on Browse.
5. Navigate to the folder where you stored your custom ANI cursor, if you didn't copy it to C:\Windows|Cursors.
6. Select the cursor you want to replace the selected item with. Keep in mind that if you replace the Normal Select item with something of your own creation, your new cursor will appear in every window on your system – try not to use something too weird.

Animation Wizard

The Animation Wizard function of PNG/MNG Construction Set will build animated MNG files for you without troubling you unduly with the unpleasant internal details of MNG files. It can be accessed by selecting Animation Wizard from the PNG/MNG Construction Set File menu, or by clicking on the Animation Wizard magic wand button in the tool bar.

There are two Animation Wizards available in PNG/MNG Construction Set. The current Animation Wizard features a user interface similar to Windows Explorer and Graphic Workshop Professional. The original wizard – or the "classic" wizard – is a traditional Windows wizard that will ask you questions and build an animation based on your responses.

The current wizard is significantly easier to use. The classic wizard is available for seasoned PNG/MNG Construction Set users who prefer it. It will be discussed in detail later in this section.

There's no need to feel embarrassed if you find that you prefer the retro feel of the classic Animation Wizard, or if you're comforted by having that detail of a William Blake painting watching you while you build animations. Sadly, there was no room for the painting in the current Animation Wizard.

Current Animation Wizard

The Animation Wizard window consists of three lists. The leftmost list is a folder navigation tree like the one in Windows Explorer and Graphic Workshop Professional. The center list will display the available image files in the folder selected by the left list. The right list will contain the graphics Animation Wizard will use to build your animations.

To build an animation with Animation Wizard:

1. Use the left window to select the folder where your source graphic files live.
2. Select the graphics to be included in your animation by clicking on them in the center window.
3. Click the Add button in the Animation Wizard tool bar to copy your selected graphics to the right list.
4. Click on the Build button in the Animation Wizard tool bar to build your animation.

When your animation is complete, the Animation Wizard window will close and your animation will open in a new PNG/MNG Construction Set document window. There are styles of shoes with a longer learning curve.

NOTE: The right list must contain two or more images before the Build button will be enabled.

The foregoing is pretty much everything you need to know to use Animation Wizard – the wizard does, however, know a few additional tricks, spells and incantations. The Animation Wizard window can be configured to your liking, and it can be operated in a number ways.

Source images: In building an animation with Animation Wizard, keep in mind that your source images can come from multiple places. You can select a folder, add some images to your animation, select a different folder, add additional images and so on. Only graphics in those formats which PNG/MNG Construction Set supports will be displayed – that's JPEG, PNG, PCX, BMP and TGA.

Thumbnails: By default, Animation Wizard will show you thumbnails of the graphic files in its lists. You can set the thumbnail size by adjusting the Animation Wizard Thumbnails value in the Setup dialog. You can enable or disable the display of thumbnails in a list by right-clicking in the list in question and selecting the Thumbnails item from the menu that appears.

Adding files: Having selected one or more files in the center list of the Animation Wizard window, you can add the selected graphics to the right list by doing any of the following:

- Click on the Add button in the Animation Wizard tool bar.
- Right-click on the center list and select Add from the menu that appears.
- Left-click in the center list and drag the files to the right list.

Use whichever procedure you find most intuitive.

To quickly add a single file to the right-list, double click on it in the center list

Note that Animation Wizard will copy your source graphics when it builds an animation – none of the foregoing clicking or dragging will affect your original graphic files.

Graphics are always added to the end of the right list – once you've added graphic files to the list, you can reposition them if needs be. Moving graphics in the right list will be discussed later in this section.

You can also add files to the right list by dragging them from another drag source Windows application, such as Windows Explorer or Graphic Workshop Professional.

Previewing files: Of necessity, the thumbnails in the Animation Wizard's lists are a bit small. You can avail yourself of a larger view of any image by right-clicking on it and selecting Preview from the menu that appears. Note that preview images are resized to fit the Preview window – they'll be easier to see, but they may not show you your source graphics with the level of detail they really possess. The actual images stored in your source graphic files will be used to build your final animation.

Testing your animation: With two or more graphics in the right list of the Animation Wizard window, you can right-click in the right list and select Test to see a trial build of the animation you've set up. Animation Wizard will build it and open it in a view window so you can see how it looks. If it's as it should be, close the view window and click on Build in the Animation Wizard tool bar to build it. If you find that you need to re-order a few images, change the Palette selection, change the Delay value or otherwise fine-tune Animation Wizard, you can do so and use the Test function again to see what you've wrought.

Palette selection: The Palette combo box in the Animation Wizard tool bar will let you select a palette management strategy for the animation under construction. Your choice should be based on the nature of your source images, and what you plan to do with your completed animation – issues that Animation Wizard can't work out for itself. Here's what the options do:

- Use As Is

  : This option will cause Animation Wizard to build your animation without modifying the colors of any of your source images. This is almost always the best choice.

- True Color

  : This option will cause Animation Wizard to promote all your source images to true color. This option is useful if you plan to do extensive color manipulation of your animated images after you create a MNG file.

- Match to Superpalette

  : If you select this option, Animation Wizard will look at all the colors in all the graphics in your animation and derive a 256-color palette which best reflects your images. It will then remap all the colors in your source images to this palette.

- Dither to Superpalette

  : If you select this option, Animation Wizard will look at all the colors in all the graphics in your animation and derive a 256-color palette which best reflects your images. It will then dither all the colors in your source images to this palette.

- Match to First Palette

  : If you select this option, Animation Wizard will build your animation using the palette of the first image you select. This will allow you somewhat more control over the final use of colors in your animation, but it can result in some truly wild color shifts if the colors used by the first image in your animation are radically different from those in your subsequent images.

- Fixed Photorealistic

  : If you select this option, Animation Wizard will dither your images to a palette with an even dispersal of colors from pure black to pure white. The results of this option will usually look a bit grainy – it's useful in situations which call for multiple animations having identical palettes.

- Fixed Drawn

  : This option will use the same palette as the Fixed Photorealistic option, but it remaps rather than dithers. This option is useful if you'll be building animations from line-art source images.

Loop: Enable this item to have your final animation loop indefinitely. Disable it to have your final animation play once and then stop. This setting can be changed after your animation is complete.

Delay: This item will set the delay per image for your final animation, in 1/1000ths of a second. Once your animation has been completed, you'll be able to change the delay values of its images by double clicking on individual Image chunks, or with the Manage function to change the delay values for multiple Image chunks at once.

Transparent source images: If you wish to build an animation from source GIF or PNG files with transparency enabled, such that your final animation preserves their transparency, Animation Wizard can keep track of your transparent elements. There are a few things to keep in mind when you do this:

1. The Wizard Preserve Transparency item in Setup must be enabled. It's enabled by default.
2. You must set the Palette selector to Match to Superpalette, Dither to Superpalette or True Color.

If you use this feature, keep in mind that Animation Wizard will mask the transparent areas of the images it imports with a solid color – it might make noticeable changes to your source images. This won't matter unless you want to disable transparency in your animation after you've built it. The color it uses can be selected in Setup.

Animation Wizard will only recognize transparent elements in source GIF and PNG files.

NOTE: If you hold down the Ctrl key when you click on Build in Animation Wizard, transparency preservation will be disabled.

Selecting images: You can select image files in a list window as follows:

- Click once on an image to select it, and a second time to unselect it.
- Right-click in a list and select Select All from the menu that appears to select all the images in the list. This item will only appear in the right-click menu if there is at least one image available to be selected.
- Right-click in a list and select Select None from the menu that appears to unselect all the images in the list. This item will only appear in the right-click menu if there is at least one image available to be unselected.
- Left-click on an image, hold down the Shift key and left-click on a second image to select all the images between them.
- Hold down the Ctrl key and left-click on multiple images to select them.

Selected files in the center list can be added to the right list, for inclusion in your final animation. Selected files in the right list can be repositioned in the list or removed. Your final animation will be assembled from all the files in the right list, selected or not.

Removing graphics from the right list: If you add image files to the right list in Animation Wizard and then change your mind about some of them, you can remove the unwanted files as follows:

1. Select the files you wish to remove, as discussed earlier.
2. Click on the Remove button in the Animation Wizard tool bar, or right-click in the right list and select Remove from the menu that appears.

Note that removing files from the right list will not delete them from your hard drive, nor will doing so remove them from the center list, should you have yet another change of heart and wish to reinstate them.

Moving and copying files in the right list: Having added graphics to the right list, you can change their order in the list, and as such in your final animation, by moving or copying them to a new location in the list. Moving one or more image files in the right list will change their locations. Copying one or more image files will duplicate them at a new location.

To Move one or more image files in the right list:

1. Select the files you wish to move, as discussed earlier.
2. Right-click in the right list on the location where you want your selected files to move to, and select Move from the menu that appears. A submenu will permit you to move your files to a location before or after the item your right-clicked on.

Copying files works the same way – select Copy rather than Move in the right-click menu.

Customizing the Animation Wizard window: You can resize the lists in the Animation Wizard window by clicking and dragging on the bars between them. The Animation Wizard window itself can also be resized to suit your desktop.

The Animation Wizard window will remember its size and folder settings between sessions.

Should you wish to return the Animation Wizard window to its default settings, hold down the Shift key when you click on the Animation Wizard button in the PNG/MNG Construction Set tool bar.

You can view your new animation by clicking on the View button. It can be saved to disk through the Save As item of the File menu.

It’s likely that the animations you create with Animation Wizard will require some post-production fine tuning. You might want to add transparent elements, move some images around, make some images display for different amounts of time and so on. Once an animation has been opened in a PNG/MNG Construction Set document window – whether it got there through the Open item of the File menu, the Animation Wizard or any of the other ways to create animations yet to be discussed – it’s ready for you to work on using the many tools available in PNG/MNG Construction Set.

Classic Animation Wizard

Animation Wizard will ask you a few things about how you want your animation to work and where the source images are, and it will then assemble your frames into a MNG file.

In creating an animation "from scratch," it’s best to think of yourself as the animation artist, and of PNG/MNG Construction Set as the animation camera. It’s your responsibility to create the source images which will form the action in your animation. PNG/MNG Construction Set will put them together into a completed animation for you.

The Animation Wizard dialog works like a conventional Windows wizard - you can move back and forth through its screens by clicking on the Back and Next buttons. Each screen is set to a default value which will usually be correct.

For the curious, the fellow with excessive hair who seems to be looking for a lost contact lens at the left side of the Animation Wizard dialog is from a painting by William Blake entitled "Ancient of Days."

When the Animation Wizard dialog appears, click on Next to get started.

The first Animation Wizard screen will ask if you want to create a MNG file for use on a World Wide Web page. This actually gives Animation Wizard some guidance about how to choose a color palette for your MNG file.

The second Animation Wizard screen will ask you if your want your MNG file to loop indefinitely or animate once and stop on the last frame. You can change this after you have built your animation if you like.

The third Animation Wizard screen will ask you how you want to handle the color for your MNG file. This is easily Animation Wizard’s sneakiest trick question. There's a discussion of palettes in the Tutorial document installed with PNG/MNG Construction Set. Here’s what these options mean:

- Use As Is

  : This option will cause Animation Wizard to build your animation without modifying the colors of any of your source images. This is almost always the best choice.

- True Color

  : This option will cause Animation Wizard to promote all your source images to true color. This option is useful if you plan to do extensive color manipulation of your animated images after you create a MNG file.

- Matched to Superpalette

  : If you select this option, Animation Wizard will look at all the colors in all the graphics in your animation and derive a 256-color palette which best reflects all your images. It will then remap all the colors in your source images to this palette. This option will usually create an animation which is most readily supercompressed.

- Dithered to Superpalette

  : If you select this option, Animation Wizard will look at all the colors in all the graphics in your animation and derive a 256-color palette which best reflects all your images. It will then dither all the colors in your source images to this palette.

- Matched to First Palette

  : If you select this option, Animation Wizard will build your animation using the palette of the first image you select. This allows you somewhat more control over the final use of colors in your animation, but it can result in some truly wild color shifts if the colors used by the first image in your animation are radically different from those in your subsequent images.

- Matched to Ortho Palette

  : If you select this option, Animation Wizard will dither your images to a palette with an even dispersal of colors from pure black to pure white. It selects a slightly different palette depending on whether you told it you wanted to create a graphic for use on the web or not. The results can look a bit grainy.

- Dithered to Ortho Palette

  : This option uses the same palette as the Photorealistic option, but it remaps rather than dithers. This option is useful if you’re building animation from line-art source images.

Unless you have a good reason to do otherwise, leave this screen set to Use As Is.

The fourth Animation Wizard screen will let you choose the delay between frames for your animation. This represents the time each image will appear before it’s replaced by the subsequent image in the sequence. MNG files represent delay times thousandths of a second. A setting of 1000, then, represents one second. The delay times of individual images or of your entire animation can be changed after Animation Wizard has created your animation. See the discussion of the Manage function elsewhere in this document.

The fifth Animation Wizard screen will let you select the source images for your animation. Click on the Select button to open a File Open dialog. You can select multiple source files at once. When you click on Open, the files you have selected will be added to the file list in Animation Wizard and the File Open dialog will appear again. Click on Cancel when you’re done selecting files. Note that you must select at least two source images to create an animation.

You can click and drag selections around the Animation Wizard list box. If you hold down the Shift key when you drop a file name, the name will be duplicated at the dropped location, rather than moved. Double-click on a file name to preview it.

The final screen of Animation Wizard will appear when you're ready to build your animation. Click on Done. Animation Wizard will load each of your source files and construct your animation. This may take a minute or two. It will display its progress in the status bar at the bottom of the PNG/MNG Construction Set application window. When it’s done, it will open a document with your animation in it.

You can view your new animation by clicking on the View button. It can be saved to disk through the Save As item of the File menu.

It’s likely that the animations you create with Animation Wizard will require some post-production fine tuning. You might want to add transparent elements, move some images around, make some images display for different amounts of time and so on. Once an animation has been opened in a PNG/MNG Construction Set document window - whether it got there through the Open item of the File menu, the Animation Wizard or any of the other ways to create animations yet to be discussed - it’s ready for you to work on using the many tools available in PNG/MNG Construction Set.

The Pegasus high-speed JPEG library included with this software is a product of Pegasus Imaging Corporation, and is available for a wide range of imaging applications. You can learn more about the Pegasus JPEG library and other imaging development tools by visiting Pegasus at their web page.

Anti-Alias

Several of the functions in PNG/MNG Construction Set – most notably the Banners and Transitions features – have optional anti-aliasing. A term as widely misunderstood as "responsible government" or "bumper-to-bumper warrantee," anti-aliasing can improve the appearance of your graphics if you use it correctly. Alternately, it can just make 'em look out of focus.

By default, the pixels used to form images on your monitor are square. They're relatively small, but being square, they render hard lines and the edges of things in a series of steps if the lines in question are not perfectly horizontal or perfectly vertical. These "jaggy" edges look less than wholly professional in some situations.

Anti-aliasing improves on the appearance of lines and edges by blending them with whatever they’ve been drawn against, as shown here.

While anti-aliasing will often improve the appearance of graphics with hard lines in them, it does have several notable drawbacks. Because it generates pixels in colors which were not present prior to anti-aliasing, it will typically reduce the effectiveness of the MNG format's compression, creating slightly larger files. It can also reduce the resolution of hard lines, causing them to appear slightly blurred.

PNG/MNG Construction Set allows for a variable degree of anti-aliasing. You can configure it through the Setup dialog.

Banners

NOTE: In addition to the banners available in the internal Banners function of PNG/MNG Construction Set, you can access forty more text effects – and a limitless palette of textures, tiles, gradients and other tools – with the Text Effects #2 Plugin and Text Effects #3 Plugin, available from Alchemy Mindworks.

The Banners function in the Edit menu of PNG/MNG Construction Set creates sophisticated text banners, which can be either still or animated. If you’re interested in creating complex banner advertisements, have at look at the Build Banner Ads that Rock article at our web page.

To create a banner, select the Banner item from the Edit menu of PNG/MNG Construction Set. The Banner dialog will appear.

The tabs at the top of the Banner dialog select the type of special effects to be added to your text. These are:

Simple:

Your text will be drawn in a solid color, with or without a drop shadow.

Embossed:

Your text will be drawn with highlight and shadow lines to make it appear to rise from the surface of your monitor.

Teletype:

Your text will be drawn one character at a time, in a solid color, with or without a drop shadow.

Glow:

Your text will be drawn against a black background with a simulated glow and optional neon tubes.

Soft shadow:

Your text will be drawn in a solid color with a soft shadow behind it.

Texture:

Your text will be cut from a tiled texture and drawn with an optional drop shadow.

Scanners:

Your text will be drawn in a solid color, with or without a drop shadow, with a bright scan line animated over it.

Waves:

Your text will be drawn as a moving wave between the Crest and Trough colors.

With the exception of Teletype, Scanners and Wave, all the Banner effects can be used either to create single lines of still text or to create text that rolls in from the right. The Teletype and Scanners effects are always animated.

There are a number of parameters to adjust for each of the banner effects. Here’s what they do. Note that not all these parameters are applicable to all the effects - they won’t appear on the tabs where they’re not needed.

- Background color:

  The color of the area behind your text and its shadow.

- Backscatter color:

  The color of the glow to the right and left of the scan line in the Scanners effect.

- Crest color:

  The color of the wave crests in the Wave effect.

- Glow color:

  The backlight color for the Glow effect.

- Outline color:

  The color used to outline the text in Textures effect.

- Scan color:

  The color of the scan line in the Scanners effect.

- Shadow color:

  The color the drop shadow behind your text will be drawn in.

- Text color:

  The color your text will be drawn in.

- Trough color:

  The color of the wave troughs in the Wave effect.

- Tube color:

  The color for the neon tubes in the Glow effect, if they’re enabled.

  Note that as with all the color buttons in PNG/MNG Construction Set, you can change any of the foregoing by clicking on the button in question and selecting a new color.

- Anti-alias:

  If this item is enabled, your text banners will be created with anti-aliased text, which will help reduce the jagged appearance of diagonal edges of characters.

- Banner Text:

  This is the text to be used to create your banner. Banner text can occupy up to 260 characters.

- Cells:

  This is the number of individual images that will be created for your animated text banner. More cells will result in smoother animation, but also in larger files. In some cases, this value is more of a suggestion than an absolute number, and PNG/MNG Construction Set might decide to create an animation with one or two more or fewer images.

- Compress Palette:

  If this item is enabled, PNG/MNG Construction Set will supercompress the palette for your text banner once it has been created, possibly creating a smaller final MNG file. This will increase the time it takes to complete a banner - you might want to leave it disabled if you’re just experimenting.

- Delay:

  This is the number of 1/1000ths of a second that each image in your animation will appear for. Increase this number to slow your animation down.

- Dither:

  Enable this item to have the colors in the textures used by the Texture effect dithered to the palette of the banner being created. Disable it to have them remapped.

- Drop shadow:

  Enable this item to show a drop shadow behind your text.

- Extra Soft:

  Enable this item to increase the softness of the soft shadows in the Banner function.

- Font:

  Click on this button to select the typeface, size and effect for the text you’d like to create. PNG/MNG Construction Set will create text banners using any alphabetic font in your system. Note that it will not work with symbol fonts or with most two-byte fonts, such as Kanji, Arabic or Hebrew.

- Frequency:

  Sets the frequency of the crests in the Wave effect.

- Leading Edge:

  Disable this item to remove the text to the right of the scan bar in the Scanners effect.

- Neon and Glow:

  These items select which of the Glow effects PNG/MNG Construction Set will create.

- Offset:

  This is the offset in pixels between your text and its drop shadow.

- Outline:

  Enable this item to have your texture banners drawn with an outline.

- Palette:

  This is the palette to be used to create your banner. Palettes are discussed in greater detail in the Reference document installed with PNG/MNG Construction Set.

- Pause:

  This is the delay for the last frame in your animation, right before it loops. It can be used to build in a pause before the banner begins to appear again.

- Radiance:

  This tells the Glow effect how bright to make the blow behind the text it draws. Very high radiance values can produce really strange banners.

- Rolling:

  Enable this item to create an animated text banner, and disable it to create a single image of the text you’re entered.

- Texture:

  Click on this button to select the texture to be used by the Texture effect. You can add your own textures to the Texture effect. The Reference document includes a more compete discussion of textures.

- Transparent:

  Enable this item to make the background color of your text banner transparent. Note that this can be changed after your banner is created by editing the Image chunks for its individual frames.

- Wide Bar:

  Enable this item to increase the width of the scan line created by the Scanners effect.

You’ll probably want to experiment with the Banner function at length to really get a feel for what it’s capable of. When you’ve entered some text, chosen a banner type and set up its parameters, click on Test to see how your banner will look as an animated GIF file.

Click on OK when you’re happy with the banner you’ve created. Your banner will open in a PNG/MNG Construction Set document window. You can save it to disk by selecting Save As from the File menu.

NOTE: Many of the banner effects create animated MNG files which can be greatly reduced by the Supercompressor.

Buttons

NOTE: The Buttons #2 Plugin, available from Alchemy Mindworks, will create a rich palette of contemporary button styles for your web pages and other media, including the really cool shiny ones nobody else seems to know how to make.

The Buttons function in the Edit menu of PNG/MNG Construction Set creates beveled button graphics. Buttons are created as PNG files.

PNG/MNG Construction Set's buttons can be of any color you like, using any font in your system.

Keep in mind that the buttons created by PNG/MNG Construction Set are just graphics. If you need clickable buttons at your web page – buttons which depress when they're clicked on – you'll need some JavaScript code to handle this. An example of the JavaScript required is included below.

You can create buttons with either round or square corners. PNG/MNG Construction Set will create suitable dark and light colors to simulate the three-dimensional contours of the buttons you specify.

Here's what the Button controls do:

- Text Color: This is the color of the text to be used to create your button.

- Button Color: This is the color of your button. The button creator will generate both lighter and darker colors based on this color. As a rule, fairly dark colors will create more convincing buttons.

- Background Color: This is the color of the background upon which your button will be drawn. This has no effect on rectangular buttons – it will be used to draw the areas outside the rounded corners of round buttons. If you enable the Transparent option, make sure you choose a background color that's markedly different from the button or text colors you've selected to avoid having transparent areas show up unexpectedly within your buttons.

- Font: This is the font to be used to draw the text in your buttons. You can select any font installed in your system.

- Drop Shadow: Enable this item to have your text drawn with a drop shadow. The drop shadow will be drawn to the right and below your text by the number of pixels specified in the offset control, in a color which is somewhat darker than your text. See below for a discussion of derivative colors.

- Highlight: Enable this item to have your text drawn with a highlight. The highlight will be drawn to the left and above your text by the number of pixels specified in the offset control, in a color which is somewhat lighter than your text. See below for a discussion of derivative colors.

- Anti-alias: If this item is enabled, your buttons will be created with anti-aliased text, which will help reduce the jagged appearance of the diagonal edges of characters.

NOTE: If you enable both Anti-alias and Transparent, you may find a thin non-transparent line around the corners of round-corner buttons. These two options should not be used together unless you're prepared to do a bit of post-production editing with the Paint function to clean up these artifacts.

- Round: Enable this item to create round-corner buttons. Disable it to create square-corner buttons. Art-college alumni, industrial graphic designers and people who paste up beer advertisements for a living will want to leave this item disabled.

- Transparent: Enable this item to make the areas outside the round corners of a round-corner button transparent. See discussion of transparent background colors above.

- Depth: This is the depth in pixels of the bevel for your button.

- Padding: This is the space in pixels between the inner edge of the bevel and the text of your button.

- Offset: This is the distance in pixels between your text and its highlight and drop shadow images, assuming you have either Drop Shadow or Highlight enabled. PNG/MNG Construction Set will not allow you to use an Offset value that's larger than the current Padding value.

A few words about derivative colors: To begin with, you need not read this next bit, and you might be happier if you didn't. Should you do so despite this warning and find that your head hurts, be comforted in knowing that the discomfort will pass as soon as you turn off your computer.

In creating buttons, PNG/MNG Construction Set will create four new colors to draw with based on the Button Color and Text Color values you have specified. The four new colors are called Bright, Dark, Text Shadow and Text Highlight. They're defined as:

Bright = Button Color * 1.25
Dark = Button Color * 0.60
Text Shadow = Text Color * 0.50
Text Highlight = Text Color * 2.00

That is, the Bright color is 25 percent brighter than the Button Color, the Dark color is 60 percent as bright as the Button Color and so on. The highlighted areas of a button are drawn in the Bright color and the shaded areas in the Dark color.

If you find that you don't like these derivative color values, you can change them. To do so, you must edit the file \Documents and Settings\... Application Data\PNGPRO.INI. Use Windows Notepad to open this file, and be sure PNG/MNG Construction Set is not running when you do so. Locate the following four lines:

`ButtonDarkFactor = 60`
`ButtonBrightFactor = 125`
`ButtonTextHighFactor = 200`
`ButtonTextShadowFactor = 50`

These numbers represent the percentage of brightness for each of the four derivative colors, multiplied by 100. As such, the factor by which the Button Color is multiplied to derive the Bright color, 1.25, is represented here as 125.

You can experiment with these values – if you choose radically nonsensical values, PNG/MNG Construction Set may draw some very strange buttons indeed.

Creating clickable buttons: You can include buttons in your web pages which animate when they're clicked. This actually involves creating two button graphics – one for the button at rest, and a second one that displayed when the button is being clicked on. The latter is referred to as the "depressed" button image. Prozak may be required in some cases.

This example of a clickable button will take you to the graphics tutorial document for PNG/MNG Construction Set if you click on it. If you don't see a button here, or if it doesn't animate correctly, your browser either has JavaScript problems or its JavaScript interpreter has been switched off.

The graphics below illustrate the two components of a clickable button. The second image was created by copying the first image and then editing out its bevel with the Paint function in the PNG/MNG Construction Set Image chunk editor. The text in the depressed image was moved down and to the right by a few pixels.

You'll also need a bit of JavaScript code to make the button work. It's important to keep in mind that bugs and JavaScript limitations in both Netscape and Internet Explorer prior to version 4.0 may prevent this script from working for users of these older browsers. In addition, some very paranoid users turn off both JavaScript and Java functionality in their browsers for fear of Java viruses. It's a good idea to provide a text link alternative for clickable buttons.

The following should appear at the top of your web page:

    <script language="JavaScript">
    <!--
    var RDY=false;
    image1=new Image();
    image1.src="HTML0043.PNG";
    image1on=new Image();
    image1on.src="HTML0044.PNG";

    function onready(name)   {
            document[name].src=eval(name+"on.src");
    }
    function offready(name)  {
            document[name].src=eval(name+".src");
    }

    RDY = true;
    function on(name)  {
            if(RDY)onready(name);
    }
    function off(name)  {
            if(RDY)offready(name);
    }
    //-->
    </script>

It's not necessary to know what all this does. The names of your two PNG button graphics should replace HTML0043.PNG and HTML0044.PNG, above. If you'll be using more than one clickable button on your web page, you can add multiple images, for example:

    image2=new Image();
    image2.src="BUTTON2.PNG";
    image2on=new Image();
    image2on.src="BUTTON2D.PNG";

Keep in mind that while these examples use upper-case file names, most web pages are designed with lower-case names. File names are not case-sensitive under Windows or DOS – they are under Unix, which is probably what will be running your web page on the web.

Here's the HTML code to add a button to your web page:

    <a href="GRAPHICS.HTM" onmousedown="on('image1');"
    onmouseup="off('image1');" onmouseout="off('image1')">
    <img src="HTML0043.PNG" border="0" name="image1"
    align="right" hspace=20></a>

Once again, you can change the URL – GRAPHICS.HTM in this case – to point to anything you like, but make sure you use the correct case.

Finally, JavaScript programming is a large and fairly complex subject. The code provided here is offered "as is" - while we're pretty sure it's solid, we are unable to provide you with assistance in applying it or modifying it for your requirements.

Chunk Types

NOTE: The current release of PNG/MNG Construction Set does not support all the chunk types in either the PNG or MNG formats, nor does it handle all the features of all the chunk types it does support.

The PNG format defines a number of chunk types to deal with data storage, display instructions to viewers and other functions. The MNG format adopts most of the PNG chunks, and adds quite a few of its own. A MNG file stores each image as an embedded PNG file.

Chunks are identified by four-character names, or "types." For example, a PNG header has the type IHDR. A MNG header has the type MHDR.

Chunks under PNG/MNG Construction Set are equivalent to blocks under GIF Construction Set.

A PNG file always begins with a header of the type IHDR and ends with an end chunk of the type IEND. A MNG file always begins with a MNG header chunk, MHDR, and ends with a MNG end chunk, MEND. A MNG file will typically include the contents of numerous PNG files, and will as such have one or more IHDR and IEND pairs within it.

At a minimum a PNG file typically includes discrete chunks to store:

- The header, IHDR, which defines the image dimensions, color type and interlacing.
- The palette, PLTE, if the image uses one.
- The background color, bCKG, if one is specified.
- Transparency information, tRNS, if it's required.
- The position of the image, oFFS, if it's required.
- The image information, IDAT.
- The end, IEND.

Advanced PNG users will note that many PNG files actually break up their compressed image information into multiple IDAT chunks, which are reassembled when the file is read. You can ignore this – PNG/MNG Construction Set always manages images as one IDAT chunk per image.

Because a PNG file can only include a single image, the number of chunks in one rarely gets particularly daunting. A PNG file with a dozen chunks is unusual. By comparison, moderately complex MNG files can quickly swell to hundreds of chunks, all of which need to be properly positioned and filled in for the file to display correctly. To keep the chunks of MNG files down to a manageable level of complexity, PNG/MNG Construction Set groups all the chunks in each PNG image embedded in a MNG file into a single chunk, which it refers to as an Image chunk. An Image chunk actually maintains all the information in the PNG chunks, above, plus two additional MNG chunks:

- The MNG frame chunk, FRAM, which stores the display time for an image, among other things.
- The object definition chunk, DEFI, which also stores the position of the image, among other things.

In working with MNG Image chunks under PNG/MNG Construction Set, you won't have to keep track of all these chunk types or, more importantly, where they must be positioned relative to each other to create a legal MNG file. The software handles all this behind your back.

You can insert new chunks into a file as discussed in the Inserting Chunks section of this document. In most cases, the chunks in your MNG files will be created for you by Animation Wizard, the Banner creator, the Transitions function and by the many other features of PNG/MNG Construction Set.

You can edit any chunk of a type supported by PNG/MNG Construction Set by double-clicking on it. An appropriate editor dialog will appear.

NOTE: The PNG and MNG formats are structured to allow software that works with them to ignore chunks with types they don't recognize. If you open a PNG or MNG file from another source in PNG/MNG Construction Set, you might encounter unsupported chunk types. If you attempt to edit one by double-clicking on a it, a message will appear to tell you so. This does not indicate a problem with either your file or the software.

Here are the chunks which can be inserted into a PNG file:

- Background bKGD – this chunk sets the background color which your PNG image is displayed over. The background color will "show through" any transparent areas of your image. This chunk is ignored by web browsers, which will allow the background of your web page to show through transparent areas. Setting a background color can be helpful in designing PNG files with transparent areas, as it will help you see how your transparencies are working. The background color will be drawn from the palette of your image if your PNG file has stored a palette-mapped image. The bKGD chunk must appear after the PLTE chunk if there is one, and before IDAT chunk it pertains to. PNG/MNG Construction Set may adjust the position of an inserted bKGD chunk if necessary.

- Compressed text ZTXT – this chunk stores comments and other text in a PNG file. Unlike the TEXT chunk, discussed below, it applies compression to the text it stores to reduce the size of your PNG files. See the discussion of the TEXT chunk and its key words for more about the contents of ZTXT chunks.

- Gamma GAMA – this chunk stores gamma information, which tells some PNG viewers how to adjust the color response of an image to properly display it. Gamma information is not interpreted by the viewer in PNG/MNG Construction Set, and in most cases you can safely ignore this chunk.

- Image IDAT – this chunk stores image information. The dimensions and color structure of an IDAT chunk are stored in its corresponding IHDR chunk. A PNG file can only store one image. Chunks which pertain to the display of an image, such as the background color, palette and transparency chunks, should be placed before the IDAT chunk.

  The PNG format defines images as being of one of several types:

  - Greyscale images, like black and white photographs.
  - True color images, having a more or less infinite range of colors.
  - Palette images, having up to 256 unique colors per image.
  - Grey scale images with alpha channel transparency.
  - True color images with alpha channel transparency.

  You might want to see the Introduction to Graphics document installed with this software for an overview of images and image types in general, and the discussion of Transparency elsewhere in this document if the phrase "alpha channel" sounds a bit like Martianspeak.

  When you insert an image into a PNG file – or if you have Animation Wizard or one of the other functions of PNG/MNG Construction Set do it for you – the image will be drawn from an image file. PNG/MNG Construction Set will read images from JPG, PNG, PCX, TGA and BMP files. If you have images in other formats which you'd like to use with PNG/MNG Construction Set, you might want to check out our Graphic Workshop Professional application to convert them.

  NOTE: If you need to port animations from the GIF format to MNG, please see our GIF Construction Set Professional application. It features a MNG export feature.

- Palette PLTE – this chunk stores the palette for palette-mapped images. PNG files which store true color images can optionally include a palette, which tells software that wants to display said images in a 256-color environment how best to color reduce them. This is rarely done, as most such computers are found only in garage sales of late. A palette can store up to 256 colors. You might want to see the Introduction to Graphics document installed with this software for an overview of images and palettes.

- Text TEXT – this chunk stores text, such as copyright information, image comments, beg notices and other bits of dogma. A PNG file can include as many TEXT and ZTXT chunks as you like, and they can appear anywhere after the IHDR chunk and before the IEND chunk. A TEXT or ZTXT chunk always includes a key word before the actual text stored in the chunk. The key word describes the nature of the text – valid key words include Comment, Creation Time and Warning, among others. The TEXT and ZTXT editor dialogs in PNG/MNG Construction Set will allow you to select from the pre-defined PNG key words, and to add your own key words for special applications.

- Time TIME – this chunk stores the time that a PNG file was most recently modified. You can only include one TIME chunk in a PNG file. The modification time will be automatically updated by PNG/MNG Construction Set each time you save your file.

- Transparency tRNS – this chunk stores transparency information. It must appear after the palette chunk and before the image chunk. See the discussion of Transparency elsewhere in this document for more about transparency.

A MNG file can include all of the foregoing chunks – as noted earlier, the chunks which comprise a PNG image are grouped together by PNG/MNG Construction Set to form Image chunks. Note that PNG/MNG Construction Set will discard TIME, TEXT and ZTXT chunks which appear between IHDR and IEND chunks in MNG files. You can't place these chunks between IHDR and IEND chunks with PNG/MNG Construction Set, this can affect MNG files from other sources.

The following are additional chunk types which can be inserted into MNG files:

- Image – when you insert an Image chunk into a MNG file, you'll be prompted for a source image file to import the image from. Note that you can select multiple files in the File Open dialog for Insert Image, which will result in more than one Image chunk being inserted. An image chunk includes all the information pertinent to one frame of a MNG file, such as transparency, palette, duration and so on. See the discussion of MNG Image chunks elsewhere in this document for more.

- Loop LOOP and End Loop ENDL – this chunk handles looping through all or part of an animation. The MNG format supports nested loops, such that you can have loops within loops, and loop specific frames of an animation. You can set the iteration counter for a loop to a specific number of times through the loop, or to Infinity to loop forever. A loop with zero iterations will cause the images within the loop to be ignored.

  Every LOOP chunk must have a corresponding ENDL chunk, which defines where the end of the loop resides. Each LOOP chunk has a identifier number, which must correspond to the identifier of its ENDL chunk. The identifier numbers of nested loops must increase with the increasing depth of the nesting, but they need not be sequential. PNG/MNG Construction Set will automatically assign identification numbers to LOOP and ENDL chunks as you insert them. You can change these by editing the LOOP and ENDL chunks in question, but be very careful in doing so.

- Termination TERM – this chunk tells a MNG viewer what to do after an animation has been displayed. If it's included, it must appear immediately after the MHDR chunk in a MNG file. In most cases, you can ignore this.

Closing PNG and MNG Files

You can close the current document window in PNG/MNG Construction Set by selecting Close from the File menu. If the file about to be closed has had changes wrought upon it since it was last saved, you will be prompted to save the changes.

If you exit PNG/MNG Construction Set with one or more document windows still open, each one will be automatically closed. This process will also prompt you to save any changed files.

Color and Balance

The Color and Balance function in the PNG/MNG Construction Set Chunk menu will allow you to fine-tune the color, brightness and contrast of your PNG and MNG files. It applies to all the colors in all the images in a file – it always makes global changes to the colors of an animated graphic. The Preview button can be used to preview what you've done. The Reset button will return all the controls to their default positions. In this position, the Color and Balance function will have no visible effect on your graphics.

Color Selection

The Color dialog will allow you to specify any color you like, out of a possible 16,777,216 – which is as close to an infinite number of colors as computers typically like to get. This dialog will allow you to specify a new color by dragging the cross-hair cursor in its color sample window around, by specifying the red, green and blue values of the color you’re after numerically or by selecting a predefined color from its list of colors.

Note that you can add your own colors to this list if you like – define a new color with the controls in the right portion of the Color dialog, and then click on Add.

Combine

The Combine function will combine two or more animations into a single animation, optionally creating a superpalette and otherwise optimizing the process to produce the most attractive results. Think of it as being analogous to splicing sections of movie film together.

Clever though it may be, it's important to understand what Combine really does so you can make the best use of it.

If you have Combine create paletted images – that is, if you disable the True Color option – your final animation will allow for a maximum of 256 colors per animation – all the images in such an animation must draw their colors from the same 256-color palette. If you combine two animations, it's a fairly safe bet that they won't have the same palettes, and will require more than 256 colors in total to keep them happy.

In this situation, the Combine function forms a superpalette – confronted with two or more animations, it will survey all the pixels in all the images in all the animations it's been asked to work with, analyse the differences in the colors involved, the number of times each color appears – and several other factors that affect the color reproduction of graphics – and come up with a list of no more than 256 colors that will allow the source images to be reproduced as faithfully as possible.

This process does entail some compromise in most cases, but it's usually remarkably effective.

NOTE: With the True Color option disabled, each time you use Combine on a source animation, the process of creating a superpalette will result in slightly more color shift. If you need to combine a number of source animations into a single animation, you'll enjoy better results if you combine them all in a single operation, rather than combining some of them, and then combining the resulting animation with still more source animations.

To use the Combine function, select Combine from the File menu of PNG/MNG Construction Set. The Combine dialog will open, as will a File Open window to permit you to select source MNG animations. You must select two or more source animations to use Combine.

The first image in each selected animation will appear in the object list of the Combine dialog.

You can change the order of the animations in the object list of the Combine dialog by clicking and dragging items around it.

Here's what the controls in Combine do:

OK: Click on OK once you have all your source animations in the Combine object list. You must have selected at least two animations for OK to be enabled.

Add: Click on Add to open the File Open dialog and select source animations to add to the object list. Because there's no real use for the Combine function until you've added some source animations to it, the File Open dialog will initially appear as soon as the Combine dialog does. You can subsequently click on Add to open it again.

Delete: Click on Delete to remove the currently-selected source animation from the Combine dialog's object list. This will not actually delete the source animation in question from your hard drive.

Loop: Enable the Loop item to have your new animation loop indefinitely. Disable this item to have it play once and then stop. Note that once your animation has been built by Combine, you can change its Loop setting by editing its Header block.

Preserve Transparency: Enable this item to have the transparency of your source animations, if it's present, preserved in your final combined animation.

Color Adjustment: Enable True Color to create a 24-bit animation with no palette restrictions and perfect reproduction of your source animations. Disable True Color to create a paletted 256-color animation with a common superpalette. If True Color is disabled, select Remap or Dither, depending upon the nature of your source animations. Remapping will replace each pixel in your source images with the closest possible color match in the palette for the animation the Combine function will create for you. Dither will attempt to approximate colors that aren't available in the palette of your new animation using alternating patterns of colors that are. Remap typically produces sharper images with less faithful color reproduction, while Dither typically produces images having better color fidelity but somewhat less detail. You can usually get away with Remap for the sorts of low-resolution animations that appear on web pages – some experimentation is unquestionably called for.

Having added animations to the Combine dialog's object list, you can preview them by double-clicking on them.

In some respects, Combine behaves like the PNG/MNG Construction Set Merge function. You might think of Merge as being a less evolved, knuckle-dragging forefather of Combine. Merge assumes that the animation having additional animations merged into it will have a suitable color palette to properly display them – not always a safe guess – while Combine juggles the palettes in question make sure that this happens. Combine also manages transparency. Merge has its uses – combining unrelated animations into an attractive finished object arguably isn't one of them.

As a final note, the Combine function can be used to bring together disparate elements into a single animation, but it has its limits. If you really want to assemble complex animations from multiple source objects, we'd like to take this opportunity to engage in some shameless self-promotion and suggest that you check out our Animation Workshop software. Not only will it assemble multiple animations, still graphics, text and various other visual phenomena into GIF files – it will let you manipulate the time indices of the objects in question, such that multiple animations can appear to play simultaneously. If you try to do this with PNG/MNG Construction Set, you'll be bashing your head against a wall by daybreak.

Creating New PNG and MNG Files

To create a blank PNG or MNG file, select New from the File menu, and select the type of file you wish to create. A blank PNG or MNG file always includes a header chunk and an end chunk. You can add chunks to a new PNG or MNG file with the Insert and Merge functions.

Crop

The Crop function in the PNG/MNG Construction Set Chunk menu will remove the area outside a selected rectangle for some or all of the images in a PNG or MNG file. When the Crop window opens, use the left button of your mouse to drag a rectangle around the area you wish to crop. Select Preview from the File menu in the Crop window to see what your cropped animation will look like. Click with the right button of your mouse to abort the Crop function, or select Done from the File menu in the Crop window to accept the cropped area you have defined.

To help you better position the crop rectangle for small images, the Crop function will display most images scaled up somewhat in the Crop window. This will not affect your final cropped image, which will appear at its correct scale.

In using the Crop function with a MNG file, the Crop dialog will show you the first selected image in the animation being cropped. You can have it show you subsequent selected image by moving the scroll bar at the right side of the Crop window.

Be careful in using the crop function – it's fairly easy to crop the first of several frames correctly only to find that subsequent frames used to have things that extended outside the crop area, but don't any longer. Once an image has been cropped, the cropped-off areas are gone for good.

NOTE: This function only affects the selected chunks in a MNG file in the current document window. To apply it to all the chunks in a MNG file, click on the Tag All button. You must click on the appropriate Apply buttons to enable the changes made in this dialog.

Copying, Cutting, Moving and Pasting Chunks

You can cut or copy the current chunk of a MNG file to the Windows clipboard using the appropriate items of the Edit menu. A chunk copied to the Windows clipboard will have its chunk structure stored as hexadecimal data defined in OEM text. Image chunks will have their image information stored as conventional Windows device-independent bitmaps.

It's a really bad idea to mess with the OEM text objects copied from PNG/MNG Construction Set and then paste them back into PNG or MNG files.

You can copy a bitmap from another application onto the clipboard as a device-independent bitmap and paste it into a PNG or MNG file through PNG/MNG Construction Set. It will be given an IDAT or Image chunk on the way in, which you can subsequently edit if you like.

The chunk copied or cut by the Copy and Cut menu items will always be the one with the insertion caret. Pasted chunks are always inserted after the chunk with the insertion caret.

You can move and copy chunks within a document window through the right-click menu. To use this feature:

1. Select one or more chunks, other than the Header chunk.
2. Right-click on the location you want to move or copy the selected chunks to. The selected chunks will be moved or copied beginning after the chunk you've right-clicked on.
3. Select Copy To or Move To from the right-click menu.

The Move To function will place your new chunks in the location you've specified, and delete the original selected chunks.

The Copy To function will place your new chunks in the location you've specified, but leave the original selected chunks as they were.

Note that Move To and Copy To will work with all the selected chunks in a document window, even if some of them are scrolled outside the visible area of the window.

Deleting Chunks

You can delete any chunk from a PNG or MNG file except the Header and End chunks. Click on the chunk in question to select it and click on the minus button in the tool bar, select Delete Chunk from the Edit menu or hit the Del key on your keyboard.

Note that all the selected chunks in the uppermost document window will be deleted by the Delete function. The number of currently selected chunks is displayed in the status bar at the bottom of the PNG/MNG Construction Set application window.

If you delete a chunk and then change your mind, you can bring it back to life through the Undo function of the Edit menu. Undo only undoes the most recent change to a GIF file.

By default, PNG/MNG Construction Set will warn you if you’re about to delete more than one chunk.

Depopulate

The Depopulate function will selectively remove Image chunks from an animation. It's extremely useful if your animation started out as digital video, and you need to thin it out for reasons of file size or good manners. You can also use this feature to turn conventional digital video into time-lapse photography.

Note that applying Depopulate to other sorts of animations – such as banner advertisements – will almost certainly cause it to remove important image elements, and turn your animation into a swamp.

The Depopulate function will create a duplicate of your original animation, with whatever degree of depopulation you specify applied to it. It will not affect your original animation.

To depopulate an animation, select the Depopulate item from the Chunk menu of PNG/MNG Construction Set. The Depopulate dialog will appear. Here's what its controls do:

Skip One Frame in: If you select this item, most of your original animation will be preserved. For example, if you set the value for this item to 8, the depopulator will keep the first seven frames, skip the eighth frame, keep the next seven frames, skip the sixteenth frame and so on. This option will allow you to adjust the running time of an animation in small increments, but it can introduce slight jumps in the action, as it removes Image chunks at irregular intervals.

Keep one Frame in: If you select this item, most of your original animation will not be preserved. For example, if you set the value for this item to 8, the depopulator will keep the first frame, skip the next seven frames, keep the eighth frame, skip the next seven frames, keep the sixteenth frame and so on. This option will allow you to radically reduce the running time of an animation.

Preserve Running Time: By default, the depopulator removes Image chunks and leaves the Delay values of the remaining chunks unchanged. The result will be an overall reduction in the running time of an animation. If you enable the Preserve Running Time item, the Delay times of the removed Image chunks will be added to the Image chunks that aren't removed, resulting in the running time of your depopulated animation being more or less the same as that of the original animation from which it was created. This process isn't always exact, as any time represented by Images chunks removed from the end of an animation, after the last preserved frame, will be lost.

The original and adjusted running times and frame counts will be displayed near the bottom of the Depopulate dialog.

In theory, setting both the Skip and Keep values to 2 should result in the same degree of depopulation. In fact, this isn't the case. The Keep depopulation logic starts with the first frame, while the Skip depopulation logic starts with the second frame. As such, there will be a difference of one frame when the depopulator reaches the end of your animation, and some discrepancy in the cumulative playing time. It's not a bug – it's a feature.

You can also depopulate digital video when it's imported into PNG/MNG Construction Set. While the results will be the same as using the Depopulate function, depopulating very large video files when you import them will be quicker and require less memory.

NOTE: Dragged items dropped into a PNG/MNG Construction Set document window are always copied, not moved. PNG/MNG Construction Set will not remove the source items once the drag operation has been completed.

You can drag JPEG, PNG, PCX, BMP and TGA images to a PNG/MNG Construction Set document window from any other suitable Windows drag source application, such as Graphic Workshop Professional. PNG/MNG Construction Set will complain if you attempt to drag files of any other format into one of its document windows, and ignore the dropped files.

You can drag most chunks between document windows within PNG/MNG Construction Set. Dragged Header, End and Time chunks will be ignored. You can't drag MNG-specific chunks to a PNG document window.

PNG/MNG Construction Set is not a drag source, and as such you cannot drag items from it to another application.

You can actually build a complete animated MNG file from scratch by creating a new document window in PNG/MNG Construction Set and dragging images into it. Having said this, you will usually enjoy more attractive results with Animation Wizard.

Export to Animated GIF

You can export MNG animations from PNG/MNG Construction Set to animated GIF files. In some cases, it's more productive to build animations as 24-bit objects in PNG/MNG Construction Set and export them to GIF files for use on the web than it is to build them as GIF animations to start with. This will usually be the case if you want to assemble a final animation from multiple 24-bit source MNG animations.

It's worth noting that the ability to export GIF animations doesn't make PNG/MNG Construction Set a replacement for GIF Construction Set Professional. GIF Construction Set can do all manner of things with GIF animations that PNG/MNG Construction Set can't, or can't do as effectively.

To export a MNG animation open in PNG/MNG Construction Set to a GIF file, select Export from the File menu, and then Export to GIF. A Save As dialog will appear.

The Export to GIF Save As dialog includes several options for the exporting process, mostly to deal with the unpleasant reality of the MNG format supporting more color depth and more flexible transparency than GIF. GIF, which dates back to the late 1980s, offers a level of sophistication comparable to that of a telephone with a hand crank on its side.

Here's what the extra settings do:

- Dither: Enable this option to have source animations that contain 24-bit graphics, or those with multiple palettes, dithered to fit them into the GIF format's limited color space. Disable it to have them remapped. Dithering typically reproduces photorealistic images more convincingly, while remapping is kinder to line art. In working with animations of the sort that appear on web pages, you can usually get away with disabling this option – switch it back on if you notice visible color banding or hitherto unseen blobs of color in your exported GIF files.
- Transparency Mask Color: This is the color that will be used to fill areas of your exported graphics which are to be made transparent. In most applications, the color you choose won't matter, as all the pixels painted in this color will be rendered transparent. The default middle gray for this option is usually a good choice.
- Transparency Threshold: This is the level of opacity below which pixels in your exported graphics will be regarded as transparent. In the likely event that the foregoing sentence meant less to you than two Martians overheard discussing the cultivation of electric vegetables, you'll probably want to have a peek at the next part of this section.

Transparency: The MNG format supports a number of truly laudable transparency structures. The GIF format supports a very crude, "all or nothing" transparency structure, which can't reproduce a fraction of the transparency options available to the authors of MNG files.

This will often prove to be less of an issue than you might expect, as few authors of MNG animations use all these toys.

In most of the graphic modes supported by MNG, image transparency can be variable. This means that select pixels can be wholly transparent, wholly opaque or partially transparent, such that they appear translucent.

When a MNG animation is exported to a GIF file, which only supports "hard" transparency, any partially transparent pixels must be exported as being either fully transparent or filly opaque. The Export to GIF function compares intermediate transparency levels to the Transparency Threshold value noted earlier. Any pixels with a transparency value of less than the threshold level will be rendered as transparent in your exported GIF files. Pixels with transparency levels equal to or greater than the threshold value will be opaque. Transparency levels, and as such the threshold setting, run from zero, for fully transparent, to 255, for fully opaque.

Depending upon how transparency was set up in your source MNG animation, forcing your exported images to adapt themselves to the hard transparency of a GIF file may result in some harsh edges and colored halos around the objects in your exported animations. There's not a lot you can do about this in an absolute sense – fine-tuning the Transparency Threshold value can minimize them in some cases.

Note that the first time you export a MNG animation to GIF under circumstances which will result in PNG/MNG Construction Set having to stomp on the transparency of your source images, you'll see a warning telling you as much. You can disable this warning for future invocations of the Export to GIF function.

Color reduction: If you export a MNG animation having 24 or 32 bits of color to a GIF file, the images in your source animation will be color-reduced fit into the limited color space of a GIF file. The Dither option, discussed earlier, will determine how the palette to be used in creating your GIF animations will be applied to the images therein.

While the color reduction function of PNG/MNG Construction Set is impressively sneaky and diabolical, it's invariably confronted with squeezing an elephant into a Volkswagen on a regular basis – that's a full-size, bad-tempered elephant and a compact, sporty little Volkswagen with impressive gas mileage and no leg room to spare. All this being the case, exporting a MNG animation to a GIF file will usually compromise the image quality of your source art at least a bit.

Export to SWF (Macromedia Flash™)

The SWF format is a multimedia graphic object format originally created by the Macromedia company for its Flash™ web objects. The SWF format can support a number of object types, including text, sounds, buttons and images.

SWF files support true-color images like MNG files, but unlike MNG, SWF is supported by web browsers for use as web page animations. You can use this feature of PNG/MNG Construction Set to add animations to your web pages which transcend the limitations of GIF files.

You can export MNG animations to SWF files to be used as Flash objects on a web page by selecting Export to SWF from the Export submenu of the File menu of PNG/MNG Construction Set.

When PNG/MNG Construction Set exports an MNG animation to SWF, it will write a Flash object which duplicates as closely as possible the performance of the original MNG file from which it was created. There are a few important catches to this process, to wit:

- All the images in an SWF file display for the same duration, whereas the display times can be set individually for the images in an MNG file. The display time for a SWF file exported from an MNG animation will be the average of the MNG display times, and the longest possible delay between images is one second. This may require that you fine-tune your MNG animation before you export it to SWF.

- For practical purposes, SWF doesn't support transparency. Users of SWF who are tight with the inner workings of Flash objects will suspect this is untrue – which it is, sort of – but for the purpose of this discussion, SWF transparency is of no meaningful use when one is discussing exporting MNG animations to SWF. If you export an MNG animation with transparency to SWF, the result will be an SWF file in which the internal members appear to be transparent, but the overall frame is opaque.

- SWF files don't include internal loop instructions. Looping can be enabled in the HTML code you use to embed your SWF file in a web page, to be discussed in a moment. As such, the Loop chunk and iteration counter of an MNG file being exported to SWF will be ignored.

Adding an SWF file to your web page isn't quite as effortless as using a GIF file – some mildly elaborate HTML is required to configure a Flash object. Here's an example of the HTML to do it. PNG/MNG Construction Set will create this for you, so you needn't damage your mind trying to understand the following unless you're naturally curious about long strings of hex numbers.

    <object
    classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
    codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,40,0"
    WIDTH="48"
    HEIGHT="48"
    id="SWFAnimation1">

    <PARAM NAME=movie VALUE="SWFAnimation1.SWF">
    <PARAM NAME=quality VALUE=high>
    <PARAM NAME=bgcolor VALUE=#ffffff>
    <embed
    src="SWFAnimation1.SWF"
    quality=high
    bgcolor=#A0A0A0
    width="48"
    height="48"
    name="An animation"
    align=""
    type="application/x-shockwave-flash"
    pluginspage="http://www.macromedia.com/go/getflashplayer">
    </embed>
    </object>

If you choose to cut and paste the forgoing to a web page, you'll need to change some of its fields. Specifically, make sure you set the file name and – most important – the width and height values, which must match the screen dimensions of your original MNG animation.

Enable Write HTML in the SWF Save As dialog of PNG/MNG Construction Set and an HTML document like the one here will be created with all the appropriate fields completed for your SWF file. The Background Color button in this dialog sets the web page background color. The HTML document so created will have the same name as your SWF file, and the extension HTML. It will be a complete page – you can extract the SWF object code with a text editor.

As of this writing, there's a discussion of the Flash object embedding syntax at Macromedia's web page. You'll also find a useful list of the embedding tag attributes there as well.

It's probably worth pointing out that having exported a graphic to the SWF format, PNG/MNG Construction Set will no longer be able to open it. The export process won't affect the original MNG file from which your SWF file has been created – hang onto your MNG animations.

While all the current web browsers ship with Flash plugins – at least, they do to the best of our knowledge – some older browsers are probably still lurking in the shadows of technology devoid of the ability to display SWF objects. This might be something to consider if you suspect your web pages attract fairly retro users.

True-color MNG files exported to SWF can be written in your choice of two formats. The fifteen-bit color-crush format will reduce the 24-bit pixels of your source MNG animation to fifteen bits. This will result in somewhat smaller final SWF files, with slightly less color resolution. In theory, areas which require fine color resolution – such as color gradients – may look slightly less attractive in this mode. This is rarely an issue.

Alternately, you can have your true-color animations exported with 32-bit pixels. This will preserve the full 24 bits of color resolution of your original MNG files. The extra eight bits in each pixel aren't used. This format looks better, but results in slightly larger files.

The export format can be set in the Setup dialog of PNG/MNG Construction Set – enable SWF Crush True Color to select the fifteen-bit write mode. The setting of this item will be ignored if you're exporting MNG animations have 256 or fewer colors.

Sound

SWF files can include sampled sound, which will allow them to make noise while they're animating at your web page. PNG/MNG Construction Set will optionally add sound to the SWF files it exports.

You can do some clever things with this feature, or you can make the users of your web pages lunge for the BACK buttons of their web browsers with all the panic and determination of a television viewer grabbing for the remote when an advertisement for cell phones, exercise machines or minivans appears on the tube. Use it wisely.

The sounds added to SWF files must be stored in WAV files. Furthermore, they must be stored in conventional WAV files having PCM-formatted data, one or two channels of sound, eight or sixteen bits of data and sampling rates of 8.0 kilohertz, 11.025 kilohertz, 22.05 kilohertz or 44.1 kilohertz. Weird little mutant WAV files with specifications other than these probably won't work, or will sound like Martians playing pinball.

PNG/MNG Construction Set cannot use MP3 files to add sound to an SWF animation, nor is it likely to be able to do so any time soon. The MP3 format is encumbered by one or more patents, and including MP3 support in PNG/MNG Construction Set would have made the software prohibitively expensive.

It's also worth noting that sound requires a lot of data to store, and SWF files having any substantial amount of noise associated with them are likely to be rather large. These large objects will require a significant amount of time for users of your web pages to download before they'll start playing. This is one of those unfortunate laws of the universe that just won't go away no matter how much you need it to do so.

To add sound to an SWF file, enable the Include Sound option in the Export to SWF dialog. Doing so will enable the Select button. Click on Select to select a WAV file for inclusion in the SWF file you're about to export.

The Select button can also audition your currently-selected WAV file. Click on the arrow to the right of Select. Your current WAV file will begin to play, and the arrow will become a square. Click on the square to silence it.

If you hold down your Shift key and click on the arrow to the right of Select, a dialog will appear with some information about your current WAV file, including its playing time. This may prove useful if you decide to plumb the turgid waters of sound synchronization, to be discussed in a moment.

It's worth pointing out that SWF files store sound using sixteen-bit simples. If you select a WAV file having eight-bit samples, it will be promoted to sixteen-bit samples when it's stored in your SWF file. As such, reducing your WAV files to eight bits will create smaller WAV files, but it won't do anything for the sizes of your SWF files.

In the event that you don't know what a sample is or why one would want to get involved with bits in any quantity, you can safely ignore the preceding paragraph.

As of this writing, there's a demonstration of an SWF animation with sound at our web page.

Sound Synchronization

Being able to add sound to a web page animation would appear to offer the prospect of creating very short movies or other animations that have synchronous sound – noises which occur coincident with whatever appears to be making them in the animations they're associated with.

You can do this with exported SWF files to some extent, albeit with a somewhat large catch and a substantial degree of fuzzy math. MNG files and SWF files express the speed at which they play back in fundamentally different ways, which makes the time conversion somewhat approximate. Specifically, a MNG file defines a delay time for each frame. An SWF file defines the number frames played per second, or the "frame rate." The frame rate is a whole number, that is, it has nothing right of its decimal point.

Here's an example of how this can be a bit of a problem. The DEFAULT.WAV file that installs with PNG/MNG Construction Set has a playing time of 00:15:48, that is, about fifteen and a half seconds. Were you to build a MNG file having 128 frames to synchronize with it, each frame would require a Delay value of 120 milliseconds. This would result in a MNG file having a playing time of 15:36, which is pretty close to the playing time of this WAV file.

To calculate the number of frames per second for an SWF file based on the playing speed of this source MNG animation, you'd use the following formula:

Frames Per Second = 1000 ÷ (Playing Time ÷ Frame Count)

This works out to:

1000 ÷ (1536 ÷ 128)

or 8.33333.

At least, it would in a universe where the duration of a second was adjustable. As was noted a moment ago, the frames per second value must be a whole number, so this gets rounded down to 8. 128 frames of animation played at eight frames per second works out to a playing time of sixteen seconds – an error of half a second.

In practice, SWF files with sound don't synchronize anywhere near this accurately even if you do make the math behave. The sound playback and video playback rates will vary with the version of the SWF plugin involved, the amount of memory and other system resources available on the machine viewing your web page and very likely the size of the feet of the power company employee who last read your electric meter.

"Flash" is a trademark or registered trademark of Macromedia, Inc.

Extract

The Extract function in the PNG/MNG Construction Set Chunk menu will allow you to select one or more chunks in an existing MNG file and have them written out to a new MNG file or to individual PNG files.

If you select more than one Image chunk and enable the Numbered option, the Extract function will create multiple numbered PNG files, each with one image in it. The file names will consist of your destination file name with sequential numbers appended to it.

NOTE: This function only affects the selected chunks in the current document window. To apply it to all the chunks in a MNG file, click on the Tag All button.

Flip and Rotate

The Flip and Rotate function in the PNG/MNG Construction Set Chunk menu will allow you to rotate some or all of the Image chunks in a PNG or MNG file in 90-degree increments, free-rotate them by any angle you like and flip them horizontally and vertically.

Note that free-rotating a bitmap will usually impose some rotation artifacts on it – you might find that your image is slightly degraded at some rotation angles. This will be a lot more apparent if you use dithered source images.

The Background color button is used to define the color of the revealed areas for free-rotated images.

Free rotation: Free rotation, or rotating images by angles which aren't evenly divisible by 90, is something of a juggling act. PNG/MNG Construction Set can do it extremely well, but it's worth knowing what the little man behind the curtain is up to.

The Flip and Rotate function includes two free rotation filters. If you enable the Maximum Quality Rotate option and your graphics are true-color images, rotation will be performed using a very sophisticated geometric rotation filter – you don't want to know how this puppy works.

If you disable Maximum Quality Rotate, or if you perform free rotation on paletted images, your graphics will be rotated using a simple trigonometric rotation filter, which is quick and precise, but will probably leave your graphics with visible jagged lines and edges.

The Maximum Quality Rotate option almost always looks better, but it takes about four times as long to rotate an image as does the trigonometric filter.

NOTE: This function only affects the selected chunks in the current document window for MNG files. To apply it to all the chunks in a MNG file, click on the Tag All button.

Frame

The Frame function can be accessed through the Chunk menu. It will draw a colored frame around all the images in an animation, adjusting the image dimensions and the screen dimensions accordingly. Because all the frames need to appear in the same location to keep a framed animation from looking like exploding salad, it will perform a Reconstruct operation first, to remove any transparency and image offsets.

The Frame function will create a new animation document once it's done, leaving your source animation unchanged.

The controls for the Frame function are as follows:

Thickness: The Thickness control will set the thickness of the frame to be drawn, in pixels. If you make this number fairly large, the frame will be more of a matt.

Color: The Color button will allow you to select a color with which to draw your frame.

Frame First Image Only: If you enable this item, the first image in your animation will be framed. All the subsequent images will be shifted right and down by the frame thickness, so they appear in the frame drawn by the first image. This will result in slightly smaller animation files.

The Frame function will increase the screen dimensions of your animation in both dimensions by twice the Thickness value you define.

You can usually reduce the file size of animations that have been processed by the Frame function by subsequently running them through the Supercompressor.

Header Chunks

The width and depth values in the header of a PNG file are defined by the image the file stores. The width and depth values in the header of a MNG file are defined as the dimensions of a rectangle which encloses all the graphic elements in the file. Both are set automatically, and need not be edited by hand.

The Header editor for PNG files will display the color type and the color depth of a single sample. Note that for true color images, each pixel requires three samples.

The Interlace switch in the header of a PNG file enables display in an interlaced pattern.

Hardware and Software Requirements

PNG/MNG Construction Set requires a Pentium or better processor to run. If you attempt to run it on a system with an 80386 or 80486 processor, it may refuse to boot.

A minimum of 128 megabytes of memory are required to run PNG/MNG Construction Set reliably, with 256 megabytes strongly recommended. Its performance will improve with increased memory. Note that if you run PNG/MNG Construction Set on a system with numerous other large applications running concurrently - such that much of your system's memory is in use by other software - its performance may be degraded.

PNG/MNG Construction Set can be used on systems with 256-color Windows screen drivers, but doing so will typically not allow you to view some PNG and MNG files with their correct colors. PNG/MNG Construction Set will perform some functions noticeably slower on such systems. A high-color or true-color Windows screen driver is strongly recommended. See the Drivers document for a complete discussion of screen drivers and how to correctly configure yours.

If you have a system with a sixteen-color Windows screen driver installed, do not attempt to run PNG/MNG Construction Set on it. PNG/MNG Construction Set may become so horrified by sixteen-color Windows screen drivers as to run screaming from the room and require eleven to fifteen weeks of intense therapy and post-traumatic counseling. You have been warned.

PNG/MNG Construction Set occupies approximately eight megabytes of hard drive space – you can recover about three megabytes by deleting all the help, documentation and example files. This is not recommended unless you store them elsewhere or you have a breathtaking understanding of the software before you do so.

You can run PNG/MNG Construction Set under Windows 98, 2000, ME, NT, XP, Vista, Windows 7 and descendants thereof.

PNG/MNG Construction Set does not require any other specific software to be installed, with the exception of the Paint application which comes with Windows.

Image Chunks

INTERIM RELEASE NOTE: The Preview button in the Image chunk editor is not implemented as yet.

The MNG format stores images by embedding all the chunks in a PNG file for each image. While agreeably flexible, this can result in a great number of chunks for a MNG animation of even moderate complexity. To keep your burden of managing the chunks in a MNG file down to something less than trying to spot all the lies in a liberal's election promises, PNG/MNG Construction Set gathers all the chunks in each of these embedded PNG files into a single chunk, which it refers to as an Image chunk.

When PNG/MNG Construction Set writes a MNG file, it expands each Image chunk back into a complete embedded PNG file, so other MNG readers will be able to correctly open and display your animation.

NOTE: Images are stored in MNG files as PNG chunk sets even if the images themselves started life in another format, such as JPEG. PNG/MNG Construction Set adds the required chunks when you insert an image, or when Animation Wizard imports graphics.

When you edit a MNG file's Image chunks, you'll actually be changing values in the chunks of the embedded PNG files in question – but you don't have to know this, and you'll probably be a lot happier if you don't think about it too much.

The Image editor dialog that appears when you double-click on an Image chunk in a MNG file includes a number of tabs to deal with the parameters an Image chunk supports. Here's what they do:

- Header: These values are actually the header values for the IHDR chunk of the embedded PNG file that stores the image in question. It will tell you the image dimensions and image type. The only thing you can actually change in this tab is the Interlace switch, and this is only included for completeness. Interlacing ignored in animations.

- Tranparency: See the discussion of Transparency elsewhere in this document for more about how transparency works in MNG files. Note that by default, Transparency is not active in a MNG Image chunk if the chunk was created by Animation Wizard. You can enable the Transparency for an Image chunk by turning on the Active switch in the upper left corner of the Transparency tab.

- Palette: The controls in the Palette tab will only be active for palette-mapped images. See the Introduction to Graphics document installed with this software for more about image types. You can edit selected colors in the palette for an Image chunk through this tab. Click on the color button to choose a palette color to edit, and use the color sliders to change the amounts of red, green and blue for the color in question.

  Click on the Interactive button in the Position tab to position your image visually. A window will appear with your image in it – click and hold within the image and drag it to change its position.

- Frame: The Frame tab allows you to define the time for which the Image chunk in question will be displayed before the animation moves along to the next image, and how it will be removed from your screen once its time is up. The "interframe delay" – the duration of an image – is measured in ticks. This may require a brief digression to explain.

  A tick is a unit of time which is defined in the MHDR header chunk of a MNG file. It's typically the shortest time used by any image in the animation. If you set the value of one tick to be one tenth of a second, setting the interframe delay of an image to one will cause it to remain on your screen for one tenth of a second. Setting the interframe delay to ten will cause the image in question to remain on your screen for ten tenths of a second, or one second.

  For most applications, it's convenient to set the Ticks value in the MHDR chunk of an animation to 1000, that is, such that each tick is 1/1000th of a second, or one millisecond. Having done so, you can set the interframe delay in the Image chunks of your animation to the number of milliseconds you want your Image chunks to remain on your screen for, and save yourself a lot of confusion.

  The Frame tab also includes a selection of framing modes, which tell a MNG viewer what to with your image after its interfame delay has expired. For practical purposes, there are two choices – it can leave your image where it is and just paint the next image over it, or it can paint over your image with the current background color, or the background of your web page, before it displays the next image in your animation.

  If your animation includes images with transparent elements, you'll want to be sure to select the latter option to prevent bits of earlier images from peeking through the transparent areas of later ones.

  Select No Background, Delay Before Image if your Image chunk does not have transparency enabled, or Background Displayed, Delay Before Image if it does have transparent elements.

  Finally, the Change Interframe Delay group allows you to define how the interframe delay should be managed. The choices are:

  - No: the interframe delay value set for this Image chunk will be ignored, and this Image will use the default interframe delay. If a previous Image chunk has not set the default value, it will be one tick.

  - For This Frame Only: the interframe delay will be set for this Image chunk, after which it will revert to the default value.

  - Change Default: the default interframe delay will be changed.

- Object: The controls in the Object tab will allow you to move the image in your Image chunk to the right and down, relative to the upper left corner of your animation. Image position is measured in pixels. Note that the Object tab must be enabled to allow the position of an image to be set. You can enable the Object controls for an Image chunk by turning on the Active switch in the upper left corner of the Object tab. You'll also need to enable the Active check boxes for the three leftmost control groups to activate the position fields.

- Image: The Paint button in the Image tab will let you edit the image in the Image chunk in question using Windows Paint.

Image Strip

The Image Strip function in the PNG/MNG Construction Set Chunk menu will export a multiple-image MNG file to a single image PNG file image strip. This will result in each of the images of your source MNG file being arranged one after the other in a long, narrow PNG file, much like the frames on a strip of movie film.

When the size of an image strip is calculated, PNG/MNG Construction Set will allow a space equal to the largest frame in the source file for each image. In a file with images of varying sizes, smaller images in the resultant image strip will be centered in a frame of the background color of the file, as derived from the background color of the source PNG file.

This feature is useful for creating Java applets which display images.

Here's what the options do:

- Horizontal Strip:

  Creates an image strip in which the images are laid out horizontally.

- Vertical Strip:

  Creates an image strip in which the images are laid out vertically.

- Transparent Background:

  This will make the background color of the image strip transparent. Use this feature carefully, as it might make some pixels in your images transparent too, if they happen to be the same as the background color.

- Descriptive Comment:

  This feature will add a TEXT chunk to your image strip PNG file which specifies the number of cells in the file and the dimensions of each cell.

NOTE: This function only affects the selected chunks in the current document window. To apply it to all the chunks in a MNG file, click on the Tag All button.

Because of the large image dimensions which usually result from creating Image strips, PNG/MNG Construction Set document windows which display them may run in Text Only mode, and not show you a preview image. This is normal, and does not indicate a problem with your image strip. See the discussion of the Tool Bar elsewhere in this document.

Inserting Chunks

There are instances in which you might want to add chunks to a PNG or MNG file by hand. You can use PNG/MNG Construction Set’s chunk insertion functions to add still more images to an animation, and to add TEXT chunks to a PNG or MNG file, for example.

If you click on any chunk in a document window, you’ll find that a blue or red line will appear along the bottom of the chunk. This is the insertion caret. Think of it as having the same function as the flashing text cursor in a word processor. Whenever you insert a new chunk into a file with PNG/MNG Construction Set, the new chunk will appear after the chunk which currently has the insertion caret. The insertion caret will appear on the chunk you’ve most recently clicked on.

With the insertion caret currently positioned, you can insert a by:

- Clicking on the plus button in the tool bar

or

- Selecting Insert Chunk from the Edit menu

In either case, a menu will appear. Select the type of the new chunk to be inserted.

If you insert a new Image or IDAT chunk, PNG/MNG Construction Set will prompt you for the name of one or more files to insert images from. You can select more than one source image at a time. Each will be created as a new Image chunk and inserted after the insertion caret.

See the section of this document which discusses Chunks for a complete discussion of the chunk types supported by PNG/MNG Construction Set.

LED Signs

NOTE: The Electronic Signs #2 Plugin, available from Alchemy Mindworks, offers numerous additional sign styles, along with optinal two-line signs, more text effects, an extended character set and countless other seriously cool features.

The LED Sign function in the Signs section of the PNG/MNG Construction Set Edit menu will allow you to create scrolling banners which resemble the LED signs found in subways, video stores, airports and many up-market churches. You can program PNG/MNG Construction Set's signs for color changes, adjustable playback speed and varying sign dimensions.

The text for an LED sign is displayed in white LEDs by default. You can change the display color at any point in the text by embedding a color code. Color codes consist of the @ sign followed by a letter. Here are the legal color codes:

- @R – red
- @G – green
- @B – blue
- @C – cyan
- @M – magenta
- @Y – yellow
- @W – white
- @K – black

Here's some example coded text:

This text is @Rred, @Ggreen, @Bblue, @Ccyan, @Mmagenta, @Yyellow, @Wand white.

This is what the colors would appear as in the LED sign function:

More will be said about black LEDs in a moment.

You can include as many color changes as you like in a sign, as long as the total text length including the color codes is no greater than 260 characters.

Here's what the controls in the LED Sign function do:

Loop: If this item is enabled, the sign will continually repeat itself. If it is not enabled, this sign will cycle once and stop.

Show Dark Pixels: If this item is enabled, LEDs that are not lit up will be displayed as dark grey, or whatever color you choose for dark pixels.

Smooth Scroll and Columns per Frame: If the Smooth Scroll option is enabled, the sign text will scroll smoothly, moving by the number of pixels defined in the Columns per Frame control. This should be set to one for the smoothest scrolling. If Smooth Scroll is disabled, the sign text will scroll by the width of one character per frame. This is arguably less attractive, but it will typically create signs with far fewer images, and as such much smaller file sizes. If you do create signs with smooth scrolling enabled and you need to reduce the final file size, try increasing the Columns per Frame value slightly. This will result in somewhat less smooth scrolling, but will reduce the number of images involved in displaying a complete sign quite a lot.

Smooth scrolling is not applicable to the Teletype effect, and is the only scroll option available for the Horizontal Split effect.

Compact LEDs: If this item is enabled, PNG/MNG Construction Set will create signs with smaller LEDs. If it's disabled, it will create signs with larger, brighter LEDs. Signs with compact LEDs also have slightly smaller frames. The sign shown here uses compact LEDs. The one at the beginning of this section features full size LEDs. Both of them arguably employ a few too many color changes.

Fit to Frame: If this item is enabled, PNG/MNG Construction Set will create a sign just wide enough to display your entire text string. If it's disabled, the width of your sign will be determined by the Columns Wide setting.

Columns Wide: This field sets the number of vertical columns of LEDs in the sign to be created if Fit to Frame is disabled. Large values will result in wider signs.

Delay: This field sets the delay in 1/1000ths of a second between images. Increase this value to slow down the scrolling of an LED sign. Note that if you adjust the Smooth Scroll or Columns per Frame items in the LED Sign dialog, you'll probably have to change this value as well.

Pause: This field sets the additional delay time for those frames which display complete text, that is, when the effect you've selected is complete.

Effect: This field selects the display effect to be generated, as follows:

Scroll: Your text will scroll into the sign area.

Teletype: Your text will appear one character at a time, with a cursor.

Horizontal Split: The top half of your text will scroll in from the right and the bottom half will scroll in from the left.

Color Overrides: As was noted earlier, you can change the colors used to display the characters of the text in an LED sign. The Color Overrides control group allows you to define the actual colors used. For example, the @Y code tells the LED sign function to display the text following it in yellow. In fact, what it really does is tell it to define the text following it using the color defined by the yellow color button in the Color Overrides control group. If you click on the yellow color button and select shocking electric purple, the text following the @Y code will be displayed in shocking electric purple.

This is not to say that shocking electric purple text is likely to impress anyone.

You can redefine all the colors if you like. Note that the names of the color buttons in the Color Overrides control group also include the @ codes the buttons refer to – this can be handy if you make radical changes to the color assignments, and forget what the original buttons looked like.

In addition to setting the colors used by the LED sign color codes, the Color Overrides control group also includes color buttons to define the background color – it doesn't have to be black – and the color used to display dark pixels.

The facility for setting the background color of LED signs probably points up the potential application of black LEDs, as noted earlier. The @K color code will select black text. This will only be useful if you select a reasonably bright background color, or if you're making LED signs for a website frequented primarily by vampires. Alternately, you can redefine the color assigned to the @K code, of course.

As an aside, black is usually represented by the letter K. It's used here because @B was already spoken for by blue. This notation turns up in commercial printing as well, where K is less likely to be mistaken for the number 8 when it's scrawled on a large printing negative in non-repro blue grease pencil by a harried press-person backed up against a deadline. As such, commercial printing colors are referred to as CMYK values, this being cyan, magenta, yellow and black.

The text in an LED sign can consist of any printable ASCII characters between ASCII 32, a space, and ASCII 126, a tilde. Any other characters will be displayed as a double dagger symbol.

The LED Sign dialog will remember the values you set in it between sessions. In the event that you click too often upon the buttons of the Color Overrides control group, and you wish to reset the LED Sign function to its default settings, hold down the Shift key when you select the LED Sign function from the PNG/MNG Construction Set Edit menu.

Keep in mind that while the LED Sign function will remember its settings between sessions, allowing you to effectively make changes to your most recent sign by rebuilding it, it cannot open previously-built LED sign animations and edit them. Once you build an LED sign animation, it's just a sequence of graphics, with no editable text.

The LED Sign function is limited to building signs with one line of text, but you're not stuck with this. You can build multiple signs, save them to individual MNG files and then use the Combine function of PNG/MNG Construction Set to assemble them into a single animation with multiple messages. If you do this, keep in mind that all the signs will need to be of the same dimensions. Disable the Fit to Frame option.

Manage

The Manage function in the PNG/MNG Construction Set Chunk menu will let you globally change the Image chunk attributes in your MNG files. It's useful for setting the delay time, position, palette and transparency of lost of Image chunks at one time without wearing your mouse down to a puddle of molten plastic.

NOTE: This function only affects the selected chunks in the current document window. To apply it to all the chunks in a MNG file, click on the Tag All button. You must click on the appropriate Apply buttons to enable the changes made in this dialog.

Here''s what the controls in this dialog do:

- Delay (in ticks):

  This field sets the duration of each selected chunk. The time is measured in ticks. The duration of a tick is set in the Header chunk. Animations created by PNG/MNG Construction Set default to having 1000 ticks per second, and as such this field can be regarded as being the duration in milliseconds for these MNG files.

- Change Default Delay:

  If you leave this item unchecked, each chunk sets its own delay. If you enable it, the default delay for the MNG file in question will be set. This makes no difference to conventional animations managed by PNG/MNG Construction Set, as every chunk has a discrete delay value. Leave this item unchecked unless you have a good reason to do otherwise.

- Remove by Background:

  If this item is enabled, each frame will be apinted over with the background color when it's time to move along to the next frame in your animation. This is essential if you create animations with transparent elements. If you see bits of previous frames in your animations, you forgot to enable this item.

- Transparency:

  Click on the Apply button to access the transparency dialog. There's a complete discussion of Transparency elsewhere in this document. Click on the Remove button to remove all transparency from the selected chunks.

- Image Chunk Position options:

  This section allows you to set the Left and Top fields of all the selected Image chunks. If you enable the Absolute option, all the chunks will be set to the values specified. Otherwise, the left and top values will be incremented by the values specified, beginning with the left and top values for the first selected chunk.

Merge

The Merge feature in PNG/MNG Construction Set Chunk menu will allow you to import all the chunks in a MNG file except for the Header and End chunk into the current document window. They will be inserted starting just after the chunk with the insertion caret. Image chunks will be handled using the same logic discussed for inserting individual Image chunks – a dialog may appear prompting you to choose a strategy for handling palette conflicts. See the section of this document dealing with Inserting Chunks for more about this.

You can also merge chunks by opening the file to be merged, selecting the chunks you're interested in and dragging them to the document window they're to be merged into.

MNG to PNG

The MNG to PNG function in the Chunk menu of PNG/MNG Construction Set will extract one frame from a MNG animation and open it as a PNG file in a new document window. You can subsequently save it to disk, or manipulate it as you would a PNG image from any other source.

The MNG to PNG function will copy the IMAGE chunk with the insertion caret to a new PNG document window. If no chunk has the insertion caret, or if the caret is on a chunk of a type other than an IMAGE chunk, it will copy the first IMAGE chunk in your animation.

This function is analogous to the Extract function, but it's less involved to use when you just need a single MNG frame stored as a PNG file.

Movies

PNG/MNG Construction Set will convert AVI and MOV digital video files into animated MNG files, and animated MNG files to AVI and MOV files. It also includes a preview function to help you check out your AVI and MOV files prior to converting them.

Converting digital video files to MNG files is relatively uncomplicated. There are, however, two possible catches to using this feature - MNG files so created can get very large, and may take a while to create. The latter will be especially true if your source digital video file has a lot of frames, or frames with relatively large pixel dimensions. Ten-megabyte digital video files aren't uncommon - ten megabyte MNG files may not suit your target application.

To import a digital video file into an MNG animation, select Import from Movie from the Import submenu of the File menu of PNG/MNG Construction Set. Select a source AVI or MOV file. A dialog will appear to let you choose a color management strategy for your MNG file. Here are the choices and what they mean. The discussion of palettes elsewhere in this document will help you sort some of these out, if a quick read of them leaves you thinking that you should have studied remedial Martian in high school.

- Use Source Image Colors:

  This option will use the existing color depth and palette in your source movie to create a MNG file. This will provide you with the most faithful reproduction of your digital video file, and is the correct choice for almost all situations.

- Dither to the 216-color safe palette:

  This option will dither all the frames in your movie to the 216-color "safe" palette. This is technically the safest choice for movies which will be displayed in web pages – it will introduce some dithering into your movies, but it will avoid radical color shifts even on embarassingly cheap computers. Not very many such computers exist outside garage sales, however, and you might not feel that this safety is worth a substantial loss in image quality.

- Remap to the 216-color safe palette:

  This option will remap all the frames in your movie to the 216-color "safe" palette.

- Dither to the 256-color orthogonal palette:

  This option will dither all the frames in your movie to the 256-color orthogonal palette.

- Remap to the 256-color orthogonal palette:

  This option will remap all the frames in your movie to the 256-color orthogonal palette.

- Dither to Superpalette:

  This option will survey all the frames in your movie and create a palette which best reflects their use of color. All your source frames will be dithered to this palette.

- Remap to Superpalette:

  This option will survey all the frames in your movie and create a palette which best reflects their use of color. All your source frames will be remapped to this palette. The superpalette options – especially Remap to Superpalette – will typically give the Supercompressor more to work with in situations wherein you want to create very small MNG files.

The Depopulate feature of the Movie Options dialog will allow you to selectively discard images in your imported digital video. It performs the same function as Depopulate in the Chunk menu of PNG/MNG Construction Set, but it does so with much more reasonable memory requirements. See the discussion of Depopulate for more about how these controls work.

You can export MNG animations to AVI or MOV movies through the Export to Movie option of the Export submenu of the File menu. For the most part, this will be a fairly transparent process – there are a few things to keep in mind, however.

- You cannot convert palette-color MNG files having differing palettes for some or all of their images to digital video files.

- Each frame in a digital video file must appear for the same length of time. PNG/MNG Construction Set will set the frame delay time for AVI and MOV files at the average delay time of all the frames in your source MNG file.

- You must have at least two Image chunks in your source MNG file to convert to a movie.

- Compressed AVI and MOV files are lossy – they sacrifice some detail for better file compression. You can adjust the amount of detail loss in a digital video file being written by PNG/MNG Construction Set by setting the AVI/MOV Quality Factor value in the Setup dialog. The quality factor can range from 10 to 10000, where 10000 will leave you with almost perfect reproduction and truly enormous digital video files. You can also turn off digital video compression entirely by disabling the Write Compressed AVI/MOV Files option in Setup. This is useful if you'll be creating AVI files to use with Visual BASIC, which can only accept uncompressed AVI files as of this writing.

- If you convert a very small MNG file to digital video, it may not play properly in some applications, as its window will be stretched to allow for a title bar, minimize and maximize buttons and so on. There's nothing actually wrong with the file - this is just how some players handle tiny files.

- Loop chunks are ignored by digital video files - you can't specify looping in a movie.

- Dithered images converted to digital video files will typically lose some quality – set the AVI/MOV Quality Factor set to a high value to minimize this.

- Converting MNG files to movies will almost always result in AVI or MOV files which are several times the size of the source MNG files from whence they have come.

The Preview Movie function of the Movie item of the File menu will let you see what a movie looks like before you convert it to MNG , and check the results of converting to digital video files. It uses the standard Windows MCI functions to play movies.

Codecs

You can set the video compression codec to be used when PNG/MNG Construction Set writes AVI files though the Select Video Compression Codec option in the Setup dialog. If the foregoing sentence didn't frighten you at least a bit, you should probably go back and read it again.

Windows allows AVI files to be written using a variety of compression methods. The logic to implement these methods is stored in blocks of code, called "codecs." You might want to think of a codec as being a black box into which Windows pours data, and out of which comes somewhat less data, the data in question having been compressed.

Windows' codec structure is somewhat chaotic, allowing as it does for codecs from third parties to be added to it. Windows maintains a pool of common codecs which can usually be relied upon to create AVI files that are compatible with other software. These are the codecs you can choose among in PNG/MNG Construction Set's Setup dialog.

The variety of codecs available in the Select Video Compression Codec function will vary between versions of Windows. They typically represent a compromise between video quality and file size – some codecs produce admirably compact files and truly awful video.

PNG/MNG Construction Set installs with default codec options that should result in attractive AVI files. You probably won't want to change this setting unless PNG/MNG Construction Set refuses to convert to the AVI format – indicating that the currently selected codec isn't available, or isn't working properly – you don't like the resulting image quality or file size or the application your AVI files are destined for won't read them.

In the latter case, disabling the Write Compressed AVI/MOV Files option in Setup – which will essentially use no codec at all – is often the quickest way around the morass of Windows' codecs.

Should you wish to reset PNG/MNG Construction Set to its default selection for AVI codecs, choose the Intel Indeo Video 4.4 codec if you're using a version of Windows prior to Windows XP, and the Intel IYUV codec for Windows XP or better.

Opening and Saving PNG and MNG Files

Any PNG or MNG file can be opened into PNG/MNG Construction Set. You can open a file either by selecting the Open item from the File menu of PNG/MNG Construction Set or by clicking on the Open button in the tool bar.

Note that PNG/MNG Construction Set will import images from several popular image file formats, but its Open function will only open PNG and MNG files. For reasons which escape most people who don't live entirely in cyberspace, some graphics on the web are named using the wrong extensions. For example, you might find files named with the extension PNG, when they're really GIF or JPG files. If you attempt to open such a file with PNG/MNG Construction Set, nothing useful will happen. We recommend that you have a look at the Identify Mystery Files function of our Graphic Workshop Professional software to sort these files out.

The Save and Save As functions of the File menu will save your current file to disk.

PNG/MNG Construction Set may append one or more TEXT chunks to the PNG and MNG files it writes. While these are discussed in greater detail elsewhere in the documentation for the software, there are two specific TEXT chunks you might want to keep in mind:

- Unregistered Shareware:

  If you use an unregistered shareware copy of PNG/MNG Construction Set to create a PNG or MNG file, a TEXT chunk to this effect will be added to the file. You can delete these within PNG/MNG Construction Set’s document windows, but they’ll be replaced as soon as you save the file.

  At such time as you register PNG/MNG Construction Set, you can nuke the Unregistered Shareware TEXT chunks in PNG and MNG files you created by opening each one with your registered software, deleting the Unregistered Shareware TEXT chunks and saving the files. Only a registered copy of PNG/MNG Construction Set can successfully delete an Unregistered Shareware TEXT chunk.

- Identify Files:

  By default, every file created by PNG/MNG Construction Set will include a TEXT chunk which identifies who created it. You can disable this feature entirely by switching off Identify Files in the PNG/MNG Construction Set Setup dialog, or configure the software to use text of your own choosing. See the discussion of the Setup dialog for more about the latter.

If you're using an unregistered evaluation copy of PNG/MNG Construction Set past its initial evaluation period, the software will add a watermark to any files it writes to disk. This watermark will appear as a small box with the word DEMO in it, near the center of each image. You will see a warning to this effect before you save a file.

The watermark will not appear in files written by a registered copy of PNG/MNG Construction Set.

The MNG format defines a fairly complex animation standard, and PNG/MNG Construction Set only supports a portion thereof. This won't prove to be a problem for the usual applications of this software. You might encounter some problems if you attempt to open MNG files from other applications. Most software that creates MNG files only supports a portion of the MNG specification – not everyone supports the same portion.

Palettes

In addition to this entry, please see Palettes and Why you Should Fear Them in the Tutorial document.

PNG/MNG Construction Set offers a selection of default palettes, to be used when it creates PNG and MNG chunks which involve palettes.

The default palette for the New function is defined in the Setup dialog. The other functions of PNG/MNG Construction Set which offer default palettes include selection controls for them.

Here's what the default palettes do:

- Black and white:

  This is a two-color palette, predictably including the colors black and white.

- Sixteen-color Windows:

  This is the standard Windows sixteen-color "reserved" palette.

- Orthogonal palettes:

  These are palettes with even dispersals of colors from pure black through pure white. Because of the mathematics of calculating these palettes, none of them include any pure greys, and the 32-color orthogonal palette is somewhat deficient in blues.

- 216-color Netscape:

  This is what's called the Netscape "safe" palette. It includes the 216 colors guaranteed to be available to all web browsers. Note that this palette is equally applicable to Internet Explorer.

- 256-color with Greys:

  This is a 224-color orthogonal palette with 32 pure grey levels added to it.

- 256 Grey Levels:

  This palette consists of 256 shades of grey from pure black to pure white, and no other colors.

In a technical sense, you should always build MNG files for use on the web using the 216-color Netscape safe palette. For reasons discussed in Palettes and Why you Should Fear Them, however, you probably will not wish to do so much of the time.

Here's a bit more palette lore. Some functions of PNG/MNG Construction Set refer to superpalettes. A superpalette is one in which all the source images destined for inclusion in an animated MNG file are surveyed, and a palette is derived for them based on how they all use color. Animations built to a superpalette typically look a lot better than those built to one of the aforementioned canned palettes.

PNG and MNG files can be creates using true color images – there's a complete discussion of true color images in the Introdction to Graphic Files document installed with this software. True color images ignore palettes, allowing for an almost infinite number of colors. The catch in using them, however, is that they usually result in really huge PNG and MNG files, and ones which resist PNG/MNG Construction Set's Supercompressor function.

Some of the effects in the Banners function of PNG/MNG Construction Set offer smooth palettes. These are custom palettes which include the greatest range of colors likely to be used in effects which involve gradations of color. For example, in creating a soft shadow, the shadow will require a lot of slight variations on the shadow color. Smooth palettes will typically provide the most attractive results for those situations where they're applicable.

Overlay

The Overlay function will allow you to create animated MNG files in which one frame appears to float over the movement in some or all of the other frames. The Overlay function is extremely effective, but it does require some forethought to use correctly.

It also helps to understand what it's really up to.

While the example overlay shown here seems to have its text appearing above the wave animation, all that this graphic really consists of is the text painted over every frame. As the text doesn't move and it's never overwritten, it appears to remain motionless and unchanging while the wave moves.

You can use this technique with any still image and a suitable animated background.

To create an overlay:

1. Build your source MNG file with the still image to be overlaid followed by all the frames of the animated background. In fact, the position of the still image relative to all the other images in your MNG file is immaterial, but putting it at the top of the list of chunks makes it easy to keep track of.

2. Select all the chunks in your MNG file by clicking on the Tag All button in the PNG/MNG Construction Set tool bar.

3. Click once on the chunk that will be your still overlay – this will be the first Image chunk in this example. The selection caret should appear.

4. Select Overlay from the Chunk menu. Click on Preview to see what your overlay looks like, or on OK to create a completed overlay animated MNG file.

There's an important catch in the foregoing. The image to be overlaid should have its background made transparent before you create the overlay. In the case of the small example overlay shown here, this has allowed the text to appear without a rectangular background, which would otherwise have obscured the animated wave. If you fail to do this, the Overlay function will warn you that there's no transparency enabled in your overlay image.

The Overlay function cannot be used with MNG files having images which use differing palettes, or images with alpha-channel transparency.

It's worth noting that Overlay only affects those animated frames which are selected. Any frames which are not selected will be copied un-overlaid to the new MNG file being created. You can use this feature to overlay more than one image, or to create overlays which appear and disappear over the course of the complete animation.

Paint Applications

The Image chunk editor includes a Paint function. The Paint function will allow you to edit Image chunk graphics. In fact, what it actually does is to save your image to a temporary BMP file, open the BMP file in a paint application, wait for the Paint application to terminate and then replace the image in question with the one in the temporary BMP file. We too were amazed that this actually works.

By default, the Paint function calls Windows Paint, the low-rent paint application that's installed with Windows.

The Windows Paint application is arguably a good example of the assertion that free software is pretty much worth what it costs. If you have a better paint package installed on your system and you wish to have PNG/MNG Construction Set's Paint function call it rather than Windows Paint, you can arrange this by editing the \Documents and Settings\... Application Data\PNGPRO.INI file.

NOTE: PNG/MNG Construction Set must not be running when you edit PNGPRO.INI. You must use the Windows NotePad application to edit this file, not a formatted word processor, such as Word or WordPad.

To change the paint software for PNG/MNG Construction Set, do the following:

1. With PNG/MNG Construction Set not running, open the Windows Notepad application and use it to open the file \Documents and Settings\... Application Data\PNGPRO.INI.

2. Locate the items

   PaintbrushName = MSPAINT.EXE
   PaintbrushPath = c:\Program Files\Accessories\MSPAINT.EXE

   in this file.

3. Change the PaintbrushName item to the name of the executable file for your paint software. If you're not sure what this is, right-click on the desktop shortcut icon for your paint software and select Properties. Note that this field must contain the executable file name only – not the file and its drive or path.

4. Delete everything after the equal sign in the PaintbrushPath item.

5. Save the file and exit Notepad.

6. Run PNG/MNG Construction Set. A Search for Paintbrush dialog will appear while PNG/MNG Construction Set searches for your paint software. If it's unable to find your paint application, you've made a mistake in reconfiguring PNGPRO.INI. Recheck the foregoing steps.

Suitable alternate paint software for PNG/MNG Construction Set's Paint function must be able to read and write graphics in the BMP format, and open files passed as command-line parameters. Pretty well all the popular image editing packages can do this.

For the most part, we will be unable to help you sort out problems with alternate paint software.

Should you wish to return PNG/MNG Construction Set to its default Paint configuration, repeat the foregoing steps using MSPAINT.EXE for the PaintbrushName item.

If you have both Windows 98 or ME and Windows NT, XP, Vista or 2000 installed on your computer as a dual-boot system, it's possible that PNG/MNG Construction Set may find MSPAINT.EXE for the wrong version of Windows. Should this happen, Windows will complain about not being able to find several required libraries when you use the Paint function. In this case, you must edit PNGPRO.INI, as discussed above, and set the PaintbrushPath item to point to the correct copy of Windows Paint.

By default, PNG/MNG Construction Set will ensure that it has a paint application available every time it runs. If it doesn't find one, it will open the Search for Paintbrush dialog and look for one. In the event that there actually is no paint application installed on your system and you don't need the Paint function, you can prevent it from doing this by disabling the Search for Paintbrush item in the Setup dialog.

Print

The PNG/MNG Construction Set Print function will print all the selected Image chunks in a MNG animation, with multiple pictures per page. The result will look like a photographic contact sheet or a story board. You can optionally have the Print function include the chunk numbers and a page footer with the name of your animation and the current page number.

To use the Print function, select the Image chunks in your current animation that you'd like to print – or click on the Tag All button in the tool bar to select all the chunks. Select Print from the File menu of PNG/MNG Construction Set.

There are several options in the Print dialog, as follows:

Print Chunk Numbers: Enable this option to have the chunk numbers of the Image chunks being printed included in your hard copy.

Print Footer: Enable this option to include a printed footer on each page of your hard copy. The footer will include the name of the MNG file being printed, and the current page number.

Caption / Footer Font: This is the font to be used to print text on your hard copy. You'll want to avoid selecting a particularly wide, ornate or weird typeface.

Chunk Font: This will be the size in points of the chunk number text.

Footer Font: This will be the size in points of the footer text.

The Print function will attempt to print the frames of your animation at a reasonable size, to make them readable while still getting a useful number of pictures on one page.

Note that Print performs the equivalent of a Reconstruct process before it prints an animation – all the frames of your animation will print as they appear in View mode, even if they include transparent elements.

In answer to the obvious question, the overprinted text which states that your pages have been printed with an unregistered copy of PNG/MNG Construction Set will not appear at such time as you register the software.

Properties

The Properties function of PNG/MNG Construction Set will provide you with some statistics about your MNG files.

To use Properties, open a MNG file in PNG/MNG Construction Set and select Properties from the File menu. Properties always applies to the uppermost open document window. It will not work with PNG files.

Properties will provide you with the following information about your MNG files:

Frame Width: The width of the frame of your image or animation in pixels.

Frame Depth: The depth of the frame of your image or animation in pixels.

Chunk Count: The number of chunks in your MNG file.

Image Chunk Count: The number of Image chunks in your MNG file.

File Size: The number of bytes of space your MNG file will occupy when it's stored or downloaded.

Uncompressed Memory: The number of bytes of memory your MNG file will require to store all its image data in memory.

Browser Memory: This is the amount of memory your MNG file will require to unpack and appear as a working animation in a web browser. This value represents an educated guess at best, as different browsers handle animation objects with different strategies. Consider it a worst-case estimate.

Duration: This is the total number of milliseconds of running time of your animation, and the number of seconds this represents.

Protection Matrix

The free and open nature of the web can often see your graphics being passed around cyberspace like drugs in a Frontline documentary. Because it's exceedingly easy to copy pictures from a web page, the pictures you create might effectively wind up in the public domain even if they're your intellectual property.

A lot of lawyers are going to get new BMWs one day soon for sorting this out.

There's no way to prevent the duplication of your web page graphics entirely, but the PNG/MNG Construction Set Protection Matrix function will help discourage it. It breaks a single-image PNG file into a matrix of small tiles. If you include these tiles in your page using the HTML code created by the Protection Matrix generator, the tiles will appear to form a seamless graphic. However, when someone uses the Save Image As function of their web browser to copy your graphic, they'll only get one tile, not the whole image.

A protection matrix can be defeated by someone who's sufficiently determined, of course – one could, for example, just screen-capture your image to a new file. However, using a protection matrix increases the difficulty in swiping your pictures considerably, and will help discourage casual image collectors.

There are several catches to the Protection Matrix feature. Because it creates multiple small PNG files to replace one original PNG file, it will increase the total downloadable file size involved. This will be considerably more apparent for files processed with an unregistered copy of PNG/MNG Construction Set. Secondly, the Protection Matrix function can only work with PNG files, not MNG animations.

Finally, a protection matrix graphic will require that you keep track of a fair number of PNG files, where once there was but a single file. This is, of course, why a protection matrix is effective at protecting your pictures.

To create a protection matrix:

1. Open a PNG file in PNG/MNG Construction Set. The image dimensions for the picture must be at least 96 by 96 pixels.

2. Select the Image chunk and select Protection Matrix from the Chunk menu.

3. The Protection Matrix dialog will allow you to set the characteristics of the matrix to be constructed. The Tile Size control determines how large each tile in your matrix will be. A smaller tile size will create more tiles, and as such an image which is more difficult to copy. Doing so will also create more files, however, and as such increase the download time for your completed image.

4. When a protection matrix is created, PNG/MNG Construction Set will write all the PNG files for your tile images and an HTML document which includes the code to display the tiles as a seamless graphic in your web page. This HTML document can include headers to make it visible in a web browser – this function is handy if you'd like to see what a protection matrix looks like before you add it to your web page. Set the Include HTML Header switch on to have the Protection Matrix function include these headers, or off to have it omit the headers and create an HTML document with just the text you'll need to inhale into your page. Note that if you leave this switch on, you can easily remove the headers later with a text editor.

Click on Save when you're ready to create a protection matrix. The Save As dialog that appears will point to the location and base name for your protection matrix files. The base name will be used to generate your tile files by appending numbers to it. As such, if you select a base file name of PICTURE.PNG, the Protection Matrix function will create new files called PICTURE_1.PNG, PICTURE_2.PNG, PICTURE_3.PNG and so on.

The Protection Matrix function will also create an HTML document using the base file name you select. In this case, it would be called PICTURE.HTML.

NOTE: Protection Matrix does not check for the existence of previous files when it creates tiles. It will overwrite existing files of the same name if they exist.

Once Protection Matrix is finished writing tiles, click on Done. You can now add the matrix code from the HTML document it created to your web page. Note that this is actually an HTML table. You'll need to be able to edit the HTML document for your web page directly to do this. If you created a your protection matrix with the Include HTML Headers switch on, be sure to delete the headers before you add this code to your web page.

Reconstruct

The PNG/MNG Construction Set Supercompressor function – and several other animation optimizers – reduce the size of MNG files by removing image information which is redundant from one chunk to the next. In effect, they prune away parts of your image frames which duplicate pixels in previous images. While this allows for smaller files, it makes such supercompressed animations decidedly tricky to edit, resize or otherwise manipulate.

The Reconstruct feature will un-supercompress animations, restoring them to a sequence of complete frames of identical pixel dimensions. It will remove transparency and un-prune frames which have been reduced. The resulting animation will be effectively what the PNG/MNG Construction Set Animation Wizard would have created for you from an initial sequence of still frames.

In using Reconstruct, note that:

1. Your reconstructed MNG animation will appear identical to your source animation if you use the PNG/MNG Construction Set view function to see it in action. You'll probably notice changes in the pixel dimensions of some of the frames.

2. If you save a reconstructed MNG animation to disk, it will likely be a lot larger than the supercompressed animation it started out as.

Once you have modified a reconstructed animation, you can run it through the Supercompressor function of PNG/MNG Construction Set to reduce its file size again.

Resize

The Resize function in the PNG/MNG Construction Set Chunk menu will allow you to change the size of one or more images in a PNG or MNG file. You can resize images by size or factor – that is, you can resize them to specific pixel dimensions or you can resize them by a percentage. Note that resizing to a factor of 100 percent has no effect. Resizing to a factor of 50 percent will result in a graphic which is half the size of the original. Resizing to a factor of 200 percent will result in a graphic which is twice the size of the original.

In resizing down, the Resize function throws away some of the pixels in your source image. In resizing up, it duplicates some of the pixels. As such, resizing always introduces some image degradation into your graphics. Use it carefully.

The Antialias option of the Resize document will improve the appearance of resized images be interpolating between pixels. This only works for true-color images. The resulting images will probably exhibit slightly poorer compression. See the discussion of alti-aliasing elsewhere in this document.

A brief digression about image filtering: In resizing images with the antialiased resize function, you can determine how the resize logic will handle the pixels affected by resizing by choosing an appropriate filter. Resizing filters are somewhat less frightening than they seem, if you understand what they're up to.

Your choice of filters will determine the tradeoff between detail retention and color smoothing in your resized graphic.

It's easiest to see what the resize filters are up to if you consider what happens when you resize an image to make it larger. A filter that performs a large amount of smoothing will sample pixels over a larger area, and as such create a smoother resize. However, in doing so, it will also tend to merge the details of your image, resulting in a softer final picture.

Here's a quick overview of the available resize filters:

Point: The Point filter performs no filtering – it does straight interpolation, with no attempt to minimize the appearance of resizing artifacts. This will result in the sharpest possible resized image, but not necessarily the most attractive one.

Box: The Box filter averages adjacent pixels. It results in minimal artifacts if the final image dimensions will be an integral multiple or sub-multiple of the original image dimensions.

Triangle: The Triangle filter works like the Box filter, but it weights the pixels it averages based on their distance from the pixel it's working on. This results in less noticeable resizing artifacts, albeit with slightly less detail retention.

Hermite: The Hermite filter works like the Triangle filter, but it adds more weight to pixels that are closer to the source pixel being calculated from. This results in slightly better detail retention.

Catrom: The Catrom filter works like the Hermite filter, with a still more non-linear weighting curve. It improves detail retention, while reducing the tendency for edge details to echo across adjacent areas.

Gaussian: The Gaussian filter blurs high-frequency details, resulting in poor detail retention but a great deal of resizing artifact removal.

Cubic and Quadratic: The Cubic and Quadratic filters work much like the Gaussian filter, but with still better artifact removal, and still more noticeable blurring. They're somewhat quicker, as well. Cubic is the blurrier of the two.

Mitchell: The Mitchell filter is compromise between the Gaussian, Cubic and Quadratic filters. It exhibits reasonable artifact removal with modest blurring.

Sinc: The Sinc filter weights pixel values at integral distances from the source pixel at zero, which minimizes blurring. However, this has the effect of making edge details echo across adjacent areas more noticeably.

Bessel: The Bessel filter works like the Sinc filter, but in two dimensions.

Lanczos, Blackman, Hanning and Hamming: The Lanczos, Blackman, Hanning and Hamming filters work like the Bessel filter, but with different weighting curves and different numbers of lobes. They usually result in a reasonable tradeoff between detail retention and resizing artifact suppression.

The Lanczos filter is a good choice for resizing photorealistic images down, 'specially if you'd rather than not damage your brain trying to get all of the foregoing by the throat. The Mitchell filter is a good choice for resizing photorealistic images up. Select the Automatic option in the Filter combo to have PNG/MNG Construction Set select one of the forgoing, depending upon how you'll be resizing your pictures.

NOTE: This function only affects the selected chunks in the current document window. To apply it to all the chunks in a MNG file, click on the Tag All button.

Reverse

The Reverse function will reverse the order of the Image chunks in a MNG file. It does not affect the position of other chunks, which will retain their original order.

Setup

The Setup dialog can be accessed by selecting Setup from the File menu, or by clicking on the Setup button in the tool bar.

- Animation Wizard Thumbnails:

  This item sets the size of the thumbnail images in the Animation Wizard.

- Anti-alias Density:

  This item sets the degree of aggressiveness with which PNG/MNG Construction Set will apply anti-aliasing in those functions for which it's available. Increasing this value will increase the degree of anti-alias compensation. See this discussion of anti-aliasing elsewhere in this document.

- AVI/MOV Quality Factor:

  This item sets the quality factor for writing AVI and MOV files. It can range from 100 for unspeakably ugly to 10000 for almost perfect reproduction. See the discussion of movies elsewhere in this document for more about this value.

- Choose Theme:

  Click on this button to select the current theme.

- Classic Animation Wizard:

  Enable this item to have PNG/MNG Construction Set display the original Animation Wizard.

- Default Palette:

  This item sets the initial palette for new PLTE chunks. There are a number of palette options. See the discussion of palettes elsewhere in this document.

  - 256 colors: This palette has an even dispersal of colors between black and white.

  - 256 colors with grey: This palette has an even dispersal of colors between black and white, but it includes 32 levels of grey.

  - 216 colors/safe: This is the palette web browsers use to remap color images to for a 256-color machine.

  - 32, 64 and 128 colors: These are evenly dispersed palettes. The 32-color palette is a bit deficient in blues.

  - 16 colors: This is the sixteen-color Windows palette.

  - 2 colors: This palette includes all the colors of the rainbow, provided they're black and white.

- Default Background Color:

  This item sets the color to be used as a background for displaying PNG and MNG files if no explicit background color is set.

- Default View Mode:

  This item sets the default view mode for new document windows. See the discussion of the tool bar elsewhere in this document.

- Display Interlaced:

  If this switch is enabled, Image chunks with interlaced images will display in interlaced order in View windows.

- Fast Color Matching:

  If this switch is enabled, PNG/MNG Construction Set will use color matching which is fast, but less accurate. Disable this switch for better dithering and closer color matches.

- Identify Files:

  If this option is enabled, PNG/MNG Construction Set will add a TEXT chunk to each PNG and MNG file it writes. The TEXT chunk will identify of the owner of the copy of PNG/MNG Construction Set that wrote the file. If you're a registered user of the software, this will be your registration name and the company you work for, as entered when you installed Windows. If you're using an unregistered copy of PNG/MNG Construction Set, this will be your name and company as entered when you installed Windows, or a message stating that this information could not be found. Alternately, you can supply your own text for this chunk. See the discussion of Identification Text File.

- Identification Text File:

  You can configure PNG/MNG Construction Set to add a TEXT chunk with your choice of text in it to every file you create. To do this, create your text in a plain ASCII text file using the Windows Notepad application. Save the file in your PNG/MNG Construction Set parent directory. Having done so, select this file using the Browse button of the Identification Text File field. Make sure the Identify Files option has been enabled.

  The text file pointed to by Identification Text File must be plain ASCII text, not a word processor document. It can contain up to 16000 characters, although few users of your PNG and MNG files will thank you for including anything like this much comment text in them. Tabs will be replaced by single spaces.

- Interlace Delay:

  This item sets the number of thousandths of a second to wait between lines when an interlaced image is displayed. This value will be ignored if the Display Interlace item is not enabled. Animated graphics don't display as interlaced.

- Maximize Paint:

  Enable this item to cause Windows Paint to be maximized when it's called from an Image chunk editor. Disable it to allow Windows Paint to open normally.

- Optimum Vertical Windows:

  Enable this item to have PNG/MNG Construction Set's document windows adjusted to use as much of the vertical window space as possible. Disable it to have them created at the default size for a document window. Note that if this item is enabled, the default vertical window size will leave a gap between it and the bottom of the PNG/MNG Construction Set application window to allow for minimized documents.

- PNG Compression:

  PNG and MNG files use lossless compression. The compression value, ranging from one through nine, sets the agressiveness of the compression. Higher compression values will typically result in smaller files, but will require longer to save the files to disk when you select Save or Save As in PNG/MNG Construction Set.

- Registration Code:

  Your registration code is provided when you register PNG/MNG Construction Set. If you received PNG/MNG Construction Set on an Alchemy Mindworks CD-ROM, it's on your invoice in the line item for PNG/MNG Construction Set. It will look like this:

  PNG/MNG Construction Set Pro REG # 12345-12-67890-88 $24.99

  If you have received a confirmation e-mail message after registering PNG/MNG Construction Set, it will appear in this message, like this:

  1 PNG/MNG Construction Set Pro REG CODE 12345-12-67890-88

  PNG/MNG Construction Set registration codes are all 17 characters long, in the form of one five-digit group of numbers, a dash, one two-digit group of numbers, a dash, a second five-digit group on numbers, a dash and a final two-digit group of numbers. You must enter your code exactly in the Registration Code field to successfully register PNG/MNG Construction Set. The dashes separating the digit groups are not entered.

  Note: Once it has been entered, your registration code will not be displayed by PNG/MNG Construction Set. If you have cause to re-install PNG/MNG Construction Set in the future, you will require your registration name and code. Write them down now and store them in a safe place.

- Registration Name:

  Your registration code is a complex checksum based on the characters of your name. If your name is not entered correctly in the Registration Name field, your registration code will not be accepted. Your registration name is printed on your invoice and is included in the confirmation e-mail message you received when you registered PNG/MNG Construction Set. It must be entered exactly - all the characters, spaces and punctuation in your registration name as it is provided to you must match what you enter in the Registration Name field.

- Select Video Compression Codec:

  Click on this button to select an alternate video compression codec for writing AVI files. Be sure to see the discussion of AVI codecs prior to doing so. Note that the dialog that will open when you click on this button is supplied by Windows, rather than by PNG/MNG Construction Set, and it may present you with options in addition to the codec selector, depending upon the version of Windows you're running. Settings other than the Compressor list will be ignored by PNG/MNG Construction Set.

- Search for Paintbrush:

  If this item is enabled and Windows Paint – the MSPAINT.EXE file – is not found when PNG/MNG Construction Set boots up, the software will search your had drive for it. Disable this item if Windows Paint is not on your system. Note that if you have Windows Paint on your system, and PNG/MNG Construction Set has located it, this item will be ignored.

- Show Startup Window:

  Enable this item to have the startup logo window displayed when PNG/MNG Construction Set boots up.

- Show Tip of the Day:

  Enable this item to have the tip of the day displayed when PNG/MNG Construction Set boots up.

- SWF Crush True Color:

  Enable this item to have true-color MNG animations exported to the SWF format written with fifteen-bit pixels, for the minimum possible file size. Disable it to have them written with 32-bit pixels, for the best possible color resolution. The setting of this item will be ignored if you're exporting MNG animations have 256 or fewer colors.

- View Mode Tool Bar:

  Enable this item to have the View window display a tool bar with buttons to start, close, pause, rewind and step through your current animation.

- View Stack Size:

  This is the size of stack for nested loops in View mode. Unless you're doing something really, really unusual, you shouldn't need anything like the default 1024 entries.

- Warn Before Deleting IDATs:

  Enable this item to be warned if you click on the Delete button or hit Del when you have selected an IDAT chunk in a PNG document window.

- Warn Before Deleting Multiple Chunks:

  Enable this item to be warned if you click on the Delete button or hit Del when you have multiple chunks selected in a document window.

- Warn Before Deleting PLTEs:

  Enable this item to be warned if you click on the Delete button or hit Del when you have selected an PLTE chunk in a PNG document window.

- Warn Before Displaying Manual:

  Enable this item to be warned before the on-line manual is displayed.

- Warn for Non-transparent Overlays:

  Enable this item to be warned if you attempt to create an overlay without transparency enabled.

- Warn Merging Different Color Types:

  Enable this item to be warned if you attempt to use the Merge function to combine MNG files with different color types.

- Warn on GIF Transparency:

  Enable this option to have the Export to GIF function of PNG/MNG Construction Set warn you when it's about to potentially crunch the transparency of whatever it's been asked to export.

- Watch Animation Wizard folders:

  Enable this item to have Animation Wizard's navigation and file panes update themselves automatically if another application changes the contents of the folder Animation Wizard is pointing to.

- Wizard Preserve Transparency:

  Enable this item to have Animation Wizard preserve the transparent elements in source GIF and PNG files when it builds an aniation. See the discussion of preserving transparency in the section of this document that deals with Animation Wizard.

- Wizard Transparent Mask:

  Click on this color button to select the color Animation Wizard will use to mask transparent areas in the animations it builds.

- Write Compressed AVI/MOV Files:

  Enable this item to have the MNG to Movie feature of PNG/MNG Construction Set write compressed AVI and MOV files. See Movies for more about this option. Disable this item if you'll be creating AVI files to use with Visual BASIC, which can only accept uncompressed AVI files as of this writing.

Shadow

The source animation for this example was created by the 3D Effects #1 Plugin Set for GIF Construction Set Professional and PNG/MNG Construction Set

The Shadow function will add shadows to your existing MNG animations to make them seem to be animating above the surface they appear before. This function is a bit sneaky, and you'll enjoy the best possible results in using it if you understand what it's actually up to.

The Shadow function processes each frame of an animation. Any pixels which are transparent are considered to be the animation's background. Any pixels which aren't transparent are considered to be the object that's about to cast a shadow.

It creates a shadow image based on the object pixels, blurs it and then assembles the shadow and the original object against a solid-color background.

In order for Shadow to work, then, you'll need to provide it with an animation having a transparent background for every frame. The animation it creates, with a shadow, will not have any transparent elements.

Here are a few other things to keep in mind about the Shadow function:

1. Shadow will work with MNG animations having up to 24 bits of color – this includes true-color and paletted images. The MNG files it creates will have 24 bits of color no matter what the color depth of the source animation was.
2. Shadow will not work with MNG animations which use alpha-channel transparency.
3. Shadow reduces paletted image transparency to either fully transparent or fully opaque.
4. The elements added to an animation by Shadow are exactly the sorts of graphics MNG's compression structure is easily fooled by. Expect your file sizes to increase somewhat.
5. Shadow removes any image Horizontal Position and Vertical Position offsets. This won't affect the appearance of your animations per se, but it can contribute to the size of your final files.

In selecting a source animation for Shadow, try to use graphics built against solid-color backgrounds similar in color to the final background color for your new animation. Light colors typically work best. If the background color of your source animation is markedly different from that of the animation you'll have Shadow create, you'll probably notice colored fringes around the object casting a shadow – pixels that were close to the transparent color of your source animation, but not close enough to be transparent.

To use Shadow, open a suitable source MNG file in a PNG/MNG Construction Set document window. Make sure it has transparent elements in every Image chunk. Select Shadow from the Chunk menu.

Here's what the controls in the Shadow dialog do:

Shadow Opacity: Shadow opacity determines how dark your shadow will be, and as such, how much it will appear to obscure the background it's cast against.

Shadow Softness: This is the amount by which your shadow will be blurred. Set it to zero for a hard shadow.

Shadow Offset: This is the number of pixels to move the shadow your object casts away from the object itself.

Background: This is the color Shadow will use as the background of the animation it will create.

Direction: Select the direction of the light that will cast the shadow to be created. The lower right option usually looks the most natural.

Of necessity, Shadow will increase the dimensions of your animation to leave room for its shadows. You might want to use the Crop function to remove some of this padding, depending on the final effect you're after.

Spin

The Spin function in the Edit menu will rotate an existing image in two dimensions. It can be used to create animated MNG animations which look like a spinning wheel or other revolving object seen face-on.

NOTE: The Spin function only rotates in two dimensions. Think of a phonograph record, or if you're too young to have seen one outside a museum, think of a CD-ROM viewed from above. This is distinct from rotation in three dimensions, which requires a three-dimensional modeling package, ray tracing and several hours of rendering time. PNG/MNG Construction Set can do the former – it cannot do the latter, nor is it likely to any time soon. If you contact us about how to do three-dimensional rotation using the Spin function, we will with the greatest regret be forced to dispatch the oft-mentioned leather-winged demon of the night to do something unspeakably nasty to you.

Here's what the Spin dialog's controls do:

- Select:

  Before you can use the Spin function, you must decide what you want to spin. The Select button will allow you to select a source image file. Source images scan be drawn from any of the supported file types listed elsewhere in this document.

- Direction:

  You can specify clockwise or counterclockwise rotation.

- Steps:

  The Steps value determines the number of degrees each image in your final file will be rotated, and as such, the number of frames in your final MNG file. This can range from 2 to 360. More steps will result in smoother animation, but with larger final files and slower movement.

- Delay:

  The Delay option sets the number of 1000ths of a second between cells for a spin effect.

- Loop:

  The Loop option determines whether the spin effect will repeat indefinitely or only rotate once.

- Transparent Background:

  The Transparent Background option sets the background color to be transparent for the spin effect you're creating.

- Maximum Rotation Quality:

  Enable this option to create animations with the best possible image quality. This will require considerably more processing time. If you disable this option, you'll probably notice a few jagged lines in your rotated graphics.

- Remap to Default Palette:

  The Remap to Default Palette option will cause your source image to be adjusted to use the currently selected default palette, as configured in the Setup dialog.

- Background:

  The Background color button sets the background to be used in creating spin effects.

- Test:

  The Test button will let you preview your graphic.

- Destination Rectangle:

  These controls determine the size of the area in which your graphic will rotate. The Maximum option will create a final MNG file which is big enough to include all the rotated parts of your source image. The Minimum option will create a final MNG file which only encompasses the area that's common to all the rotated frames. The Original option will create a final MNG file which has the same dimensions as your source image.

- Palette Compression:

  If the palette compression option is enabled, your MNG file will be stored with the least possible color depth.

Note that rotating a bitmap will usually impose some rotation artifacts on it – you might find that your image is slightly degraded at some rotation angles. This will be a lot more apparent if you use dithered source images.

Status Panels

NOTE: The Electronic Signs #2 Plugin, available from Alchemy Mindworks, offers numerous additional sign styles, along with optinal two-line signs, more text effects, an extended character set and countless other seriously cool features.

The Status Panel function in the PNG/MNG Construction Set Edit menu Signs section will allow you to create scrolling banners which resemble the displays found in various bits of consumer technology. You can program PNG/MNG Construction Set's status panels for color changes, adjustable playback speed and varying dimensions.

The text for a status panel is displayed in blue pixels by default. You can change the display color at any point in the text by embedding a color code. Color codes consist of the @ sign followed by a letter. Here are the legal color codes:

- @R - red
- @G - green
- @B - blue
- @C - cyan
- @M - magenta
- @Y - yellow
- @W - white
- @D - default

Here's some example coded text:

This text is @Rred, @Ggreen, @Bblue, @Ccyan, @Mmagenta, @Yyellow, @Wand white.

This is what the colors would appear as in the Status Panel function:

You can include as many color changes as you like in a sign, as long as the total text length including the color codes is no greater than 260 characters.

Here's what the controls in the Status Panel function do:

Loop: If this item is enabled, your animated status panel will continually repeat itself. If it is not enabled, this animation will cycle once and stop.

Fit to Text: If this item is enabled, PNG/MNG Construction Set will create a status panel just wide enough to display your entire text string. If it's disabled, the width of your status panel will be determined by the Columns setting.

Show Cursor: If this item is enabled, a cursor will appear before the text being displayed by the Teletype effect, as in the example status panel at the beginning of this section.

Soft Shadow: If this item is enabled, PNG/MNG Construction Set will create a status panel with a soft shadow behind it, like the one at the beginning of this section.

Columns: This field sets the number of vertical columns of lights in the status panel to be created if Fit to Text is disabled. Large values will result in wider panels.

Delay: This field sets the delay in 1/1000ths of a second between images. Increase this value to slow down the scrolling of a status panel.

Pause: This field sets the additional delay time for those frames which display complete text and a blank panel at the end for the Scroll effect.

Shadow Softness: If you have enabled the Soft Shadow option, above, this item will let you define the degree of softness for the soft shadow around your status panel.

Shadow Offset: If you have enabled the Soft Shadow option, above, this item will let you define offset of the shadow, and hence the apparent distance of your status panel above the surface of your web page. If you encounter real technology with its status display hovering above the rest of the hardware like this, you'll want to get in touch with the manufacturer's warrantee department ASAP.

Shadow Density: If you have enabled the Soft Shadow option, above, this item will let you define the density of the shadow.

Effect: This field selects the display effect to be generated, as follows:

Scroll: Your text will scroll into the panel area.

Teletype: Your text will appear one character at a time, with an optional cursor.

Color Overrides: As was noted earlier, you can change the colors used to display the characters of the text in a status panel. The Color Overrides control group allows you to define the actual colors used. For example, the @Y code tells the Status Panel function to display the text following it in yellow. In fact, what it really does is tell it to define the text following it using the color defined by the yellow color button in the Color Overrides control group. If you click on the yellow color button and select shocking electric purple, the text following the @Y code will be displayed in shocking electric purple.

This is not to say that shocking electric purple text is likely to impress anyone.

You can redefine all the colors if you like. Note that the names of the color buttons in the Color Overrides control group also include the @ codes the buttons refer to – this can be handy if you make radical changes to the color assignments, and forget what the original buttons looked like.

In addition to setting the colors used by the Status Panel color codes, the Color Overrides control group also includes color buttons to define the background color – it doesn't have to be gray – and the default color, the color that will be used if no @ codes are present in your text.

The text in a status panel can consist of any printable ASCII characters between ASCII 32, a space, and ASCII 126, a tilde. Any other characters will be displayed as a double dagger symbol.

The Status Panel dialog will remember the values you set in it between sessions. In the event that you click too often upon the buttons of the Color Overrides control group, and you wish to reset the Status Panel function to its default settings, hold down the Shift key when you select the Status Panel function from the PNG/MNG Construction Set Edit menu.

Keep in mind that while the Status Panel function will remember its settings between sessions, allowing you to effectively make changes to your most recent status panel by rebuilding it, it cannot open previously-built status panel animations and edit them. Once you build a status panel animation, it's just a sequence of graphics, with no editable text.

The Status Panel function is limited to building panels with one line of text, but you're not stuck with this. You can build multiple signs, save them to individual MNG files and then use the Combine function of PNG/MNG Construction Set to assemble them into a single animation with multiple messages. If you do this, keep in mind that all the signs will need to be of the same dimensions. Disable the Fit to Text option.

You'll probably want to select the True Color option in the Combine dialog if you do this.

A word about file size: The Status Panel function will produce fairly large MNG files if it's left to its own devices. Its animations, however, include a lot of redundant image data between frames, and they supercompress extremely effectively. Use the Supercompress function in the File menu of PNG/MNG Construction Set with the Prune Overlapping Frames and Redundancy Compression options enabled and your status panel animations will be squeezed down to a fraction of their former immensity.

Supercompressor

If you're creating MNG animations for an application in which file size is a consideration, you can probably reduce their size with the PNG/MNG Construction Set supercompressor.

It's important to keep in mind what the supercompressor is really up to. All MNG files are compressed. The supercompressor will attempt to meddle with the chunks in your MNG files to make them more compressible. In some cases it can do quite a bit in this respect, and in others it will be wholly ineffective. If there's nothing to squeeze out of your MNG file, the supercompressor will not make it any smaller.

The supercompressor makes MNG files smaller by doing one or more of the following to them:

Palette Compression: Palette compression is only applicable to images having 256 or fewer colors – true-color images don't have palettes, and as such, no palettes to compress. In applying palette compression, the supercompressor will survey each image in an animation and delete those colors from the palettes thereof which aren't actually referenced by any pixels. If it finds enough unused colors, it be able to make the palette smaller, and hence recompress the file with a lower color depth.

Prune Overlapping Frames: If an animation consists of multiple frames in which only the area in the middle of each frame actually contains action that changes, the supercompressor will prune away the edges of the frames and move what's left down and to the right so it appears in the correct location.

Redundancy Compression: If an animation consists of multiple frames with a lot of identical areas, the supercompressor will replace the identical pixels with a transparent color. Since all the replaced pixels will be one color – the transparent color – and areas of pixels that are all the same color typically compress better than areas of pixels that are a variety of colors, the resulting MNG file will get smaller.

Chunk Stripping: MNG files don't need TEXT or ZTXT chunks to display themselves. The supercompressor can remove them for you.

The supercompressor will not change the way your animation appears, but it might well change what the individual frames look like. It's a profoundly good idea to save your original source images under a different file name when you use the supercompressor. Once an animation has been supercompressed, it will often be very, very difficult to edit.

The supercompressor will not perform pruning or redundancy compression on MNG files which have one or more images with transparency enabled. These functions will also be disabled if your animation includes both paletted and true-color images.

To use the supercompressor, open a MNG file in PNG/MNG Construction Set and select Supercompressor from the File menu. Note that you can disable any compression types you don't want to use, and the supercompressor will disable any compression types it decides are inappropriate for your MNG file. Click on Start to begin compressing. The OK button will be enabled when the supercompressor is done. When you click on OK, your supercompressed graphic will open in a new document window.

If the supercompressor can’t find anything to squeeze out of your MNG file, it will tell you so and the OK button will not be enabled.

NOTE: The supercompressor is good, but it’s not God. It can’t take a half-megabyte bloated pig of a MNG file and Jenny Craig it down to ten kilobytes just ‘coz you really need a small file. Really huge complex animations typically require a rethink to get them down to manageable dimensions.

System Information

The System Information dialog will provide you with an overview of the configuration of your computer. This can be useful in unraveling configuration issues. It includes the following:

- Screen Width and Screen Depth:

  These are the dimensions in pixels of your current screen display mode.

- Network Present:

  If this field is set to Yes, Windows is of the opinion that your computer is connected to a network of some sort.

- Slow Machine:

  This field indicates Windows' assessment of the speed of your computer – don't take it personally.

- Windows Version:

  This is the internal version number for your installation of Windows.

- Machine Owner:

  This is the owner name used when you installed Windows.

- Organization:

  This is the organization or company name used when you installed Windows.

- Color Depth:

  The last item in the System Information dialog indicates the number of colors which your current Windows screen driver can display without dithering. If this number is 256 or less, PNG/MNG Construction Set is running a lot slower and looking a lot uglier than it needs to. See the Drivers document for help in reconfiguring your Windows screen driver.

Text Chunks

If you double click on a TEXT or ZTXT chunk, a Text chunk editor will appear. You can modify the text in a Text chunk by editing the contents of this dialog.

The Format button changes the font used to display the text in PNG/MNG Construction Set’s Text chunk editors. It does not affect how it will appear in other applications which might display your Text chunks.

PNG/MNG Construction Set may append one or more TEXT chunks to the PNG and MNG files it writes. While these are discussed in greater detail elsewhere in this document, there are two specific TEXT chunks you might want to keep in mind:

Unregistered Shareware: If you use an unregistered shareware copy of PNG/MNG Construction Set to create a PNG or MNG file, a TEXT chunk to this effect will be added to the file. You can delete these within PNG/MNG Construction Set’s document windows, but they’ll be replaced as soon as you save the file.

At such time as you register PNG/MNG Construction Set, you can nuke the Unregistered Shareware TEXT chunks in PNG and MNG files you created by opening each one with your registered software, deleting the Unregistered Shareware TEXT chunks and saving the files. Only a registered copy of PNG/MNG Construction Set can successfully delete an Unregistered Shareware TEXT chunk.

Identify Files: By default, every file created by PNG/MNG Construction Set will include a TEXT chunk which identifies who created it. You can disable this feature entirely by switching off Identify Files in the PNG/MNG Construction Set Setup dialog, or configure the software to use text of your own choosing. See the discussion of the Setup dialog for more about the latter.

Themes

The tool bar buttons and several other graphic elements that appear throughout PNG/MNG Construction Set are referred to collectively as a "theme." As this may imply, if you don't like the theme PNG/MNG Construction Set installs with, you can change it.

To change the current theme, click on the wrench button in the tool bar to open the Setup dialog. Click on the Choose Theme button in the browser tab. A dialog will open to show you the available themes.

Click on the new theme you'd like to have PNG/MNG Construction Set use and click on OK. You must exit and restart PNG/MNG Construction Set to make your new theme active.

It's worth noting that, as cool as they are, the shaded graphics in PNG/MNG Construction Set's default theme require time and system resources to initialize. This contributes to the time PNG/MNG Construction Set requires to boot up. On a 1.5 gigahertz system with half a megabyte of memory, initializing the tool bar requires less than a quarter of a second – probably nothing to get into a lather over. If you're running PNG/MNG Construction Set on a very slow system, or one with perilously little memory, you might want to select one of the simpler themes, such as Retro, which require much less initialization.

Admittedly, if you're running PNG/MNG Construction Set on a system for which the initialization time of your tool bar theme becomes an issue, you have much larger matters to be concerned with.

PNG/MNG Construction Set's themes reside in a folder named theme in the parent directory of PNG/MNG Construction Set. It took weeks to think that one up, and we're considering applying for a patent on it. The themes are stored in files named like this:

THEME_Contemporary.DLL

The bit after "THEME_" is the name of the theme as it will appear in PNG/MNG Construction Set.

It's a grotesquely bad idea to rename, delete or attempt to modify the theme files.

As of this writing, there are a no plans to release the details of PNG/MNG Construction Set's theme files, and as such users of the software will not be able to create their own themes. This having been said, we'd be interesting in hearing from anyone with a good idea for one – preferably with the graphics to go along with it.

Lots of other applications use themes, including Windows itself. Alchemy Mindworks' theme files are specific to our applications. You can't install them in other software, or use the themes from other software in PNG/MNG Construction Set.

Finally, it's worth noting that in the event that PNG/MNG Construction Set's themes get deleted or thoroughly mangled by mysterious forces of darkness – you've got to hate it when they do that – PNG/MNG Construction Set will run with an internal theme that looks a lot like the Retro theme option, and it will tell you about it every time it boots up. You can remedy this situation by selecting a new theme in the Setup dialog, as discussed earlier, or if all the themes are toast, by reinstalling PNG/MNG Construction Set. This is something of a fail-safe, and should never actually happen.

Tile

The Tile function will create a new animation having the dimensions set by the Width and Depth fields of the Tile window, and your source animation tiled over its area. This is similar to the effect of a tiled web page background.

The Preview button in the Tile window will let you see what your tiles look like before you build a final animation.

This function is useful in creating a tiled area for use in other applications, such as Alchemy Mindworks' Animation Workshop. If you just want a tiled web page background, you should use a single tile, as a GIF file created with GIF Construction Set Professional, and add it to the BODY element in your HTML document.

Tool Bar

The PNG/MNG Construction Set tool bar provides access to the most commonly used functions supported by the software. All its buttons duplicate functions available in the main menu, but buttons are easier to get at than menus. The tool bar buttons have associated tip windows – if you forget what a button does, place your mouse cursor over it for a moment and a window will appear to explain its function.

The functions dispatched by the tool bar always pertain to the topmost document window if you have multiple documents open. The tool bar buttons which process chunks will be disabled if no files are selected in the topmost document window. The button colors you see may vary, depending on the currently selected button color set.

Here are all the tool bar buttons. Each of these functions is explained in detail elsewhere in this document. Your tool bar graphics may differ from the ones shown here, depending upon your choice of Themes.

Open: Opens a PNG or MNG file into a new document window.

Save: Saves the currently active document window to disk.

View: Views the PNG or MNG file in the current document window.

Animation Wizard: Activates the Animation Wizard, as discussed elsewhere in this document.

Insert Chunk: Inserts one or more chunks after the insertion caret in the current document window.

Delete Chunk: Deletes all the selected chunks in the current document window.

Select All: Selects all the chunks in the current document window.

Unselect All: Unselects all the chunks in the current document window.

Manage: Manages all the selected chunks.

Help: Displays the contents of the Help for PNG/MNG Construction Set.

Setup: Accesses the Setup dialog for PNG/MNG Construction Set.

Exit: Exits PNG/MNG Construction Set.

NOTE: Some of the tools in the tool bar require that one or more chunks in the current document window be selected before they'll become active. Some only work for PNG or MNG files, but not both.

The View Mode combo box at the left side of the tool bar selects the degree of zoom used to display the preview images in the current document window. The default view mode, 100 Percent, will display the images in a PNG or MNG file at their natural size. There's a limit to the dimensions of a Windows list box item, and PNG/MNG Construction Set will not allow you to select a view mode that will exceed this. If you attempt to do it, it will reset the View Mode combo box to a lower value.

The Text Only view mode will display just the descriptive chunk captions for a file, and no preview images. PNG/MNG Construction Set will automatically select this mode if you attempt to view a really enormous PNG or MNG image.

Transparency

INTERIM RELEASE NOTE: The mask editor for alpha channel transparency is not implemented in the current release. As of this writing, the major web browsers only support hard transparency, wherein transparent elements are wholly transparent or not transparent at all. Grey-scale transparency is not implemented as yet. Full alpha-channel viewing is supported for PNG files, and alpha channel images can be imported from PNG, BMP and TGA source files.

Images in PNG and MNG files can optionally include transparent elements. If you're familiar with how GIF files handle transparency, be aware that the whole works is substantially different for PNG and MNG files. Under GIF, each image was allowed one transparent color, and transparent elements could only be wholly transparent. PNG and MNG images use what's called "alpha channel" transparency, which allows for multiple transparent colors or pixels, with each one being able to support a specified degree of transparency. This allows PNG and MNG graphics to blend with their backgrounds.

Transparency is available in different forms for the different graphic types supported by PNG and MNG files. Specifically:

- Grey-scale images without alpha transparency can have one grey level designated as being wholly transparent. All other grey levels are opaque.

- True color images without alpha transparency can have one color designed as being wholly transparent. All other colors are opaque.

- Palette-mapped images can have as many colors as exist in their palettes designated as being completely transparent or transparent to a specified degree.

- Grey scale images and true color images with alpha channel transparency can have every pixel set to a specified degree of transparency.

If you're unsure which type of image you're trying to add transparency to, check its PNG image header – the IHDR chunk for a PNG file, or the Header tab in the Image editor for a MNG file.

NOTE: Transparent images are always displayed against a background color in PNG/MNG Construction Set. This color will be replaced by the background of your web page when you add your PNG and MNG graphics to an HTML document. The background color that PNG/MNG Construction Set uses will be defined by the bKGD chunk for PNG files or by the BACK chunk for MNG files, if these chunks are present, or by the Default Background Color in the PNG/MNG Construction Set Setup dialog if a background color chunk cannot be located. The Default Background Color value is initially set to white. To properly view your graphics with transparency, you might have to either add suitable background color chunks to your PNG or MNG files, or set the Default Background Color value in Setup to a color which is visible in the transparent areas. The color used by the background of your web pages would be a good choice.

To add transparency to a palette-mapped image in a PNG file:

1. If there is no tRNS chunk presently in the file, click on the plus button in the tool bar and insert one. Note that PNG/MNG Construction Set will position your new tRNS chunk correctly no matter what the currently selected chunk is. Don't worry about the initial number of transparent colors.

2. Double-click on the tRNS chunk to access its editor.

3. Click on the eyedropper tool. A window with your graphic will open. Click somewhere in the area you wish to make transparent. You might see a message which says that the color you have selected is not in the transparency list. Click on Yes to add it.

4. Set the Alpha Level for your selected color to zero to make that color transparent. The alpha level can range from zero for fully transparent to 255 for fully opaque, with intermediate values generating intermediate degrees of transparency.

5. If you want to make another color transparent, use the eyedropper tool to select it or select it from the list of transparent colors and set its Alpha Level value.

To add transparency to a palette-mapped image in a MNG file:

1. Double-click on the Image chunk in question to access its editor.

2. Select the Transparency tab and enable its Active switch if necessary.

3. Click on the eyedropper tool. A window with your graphic will open. Click somewhere in the area you wish to make transparent. You might see a message which says that the color you have selected is not in the transparency list. Click on Yes to add it.

4. Set the Alpha Level for your selected color to zero to make that color transparent. The alpha level can range from zero for fully transparent to 255 for fully opaque, with intermediate values generating intermediate degrees of transparency.

5. If you want to make another color transparent, use the eyedropper tool to select it or select it from the list of transparent colors and set its Alpha Level value.

To add transparency to a true color or grey scale image in a PNG file:

1. If there is no tRNS chunk presently in the file, click on the plus button in the tool bar and insert one. Note that PNG/MNG Construction Set will position your new tRNS chunk correctly no matter what the currently selected chunk is.

2. Double-click on the tRNS chunk to access its editor.

3. Click on the eyedropper tool. A window with your graphic will open. Click somewhere in the area you wish to make transparent. Alternately, click on the color button and use the More options to enter the red, green and blue values of the color you want to make transparent.

To add transparency to a true color or grey scale image in a MNG file:

1. Double-click on the Image chunk in question to access its editor.

2. Select the Transparency tab and enable its Active switch if necessary.

3. Click on the eyedropper tool. A window with your graphic will open. Click somewhere in the area you wish to make transparent. Alternately, click on the color button and use the More options to enter the red, green and blue values of the color you want to make transparent.

NOTE: Simple transparency for true color and grey scale images usually requires that you manually paint the area to be transparent with a single solid color. Even minute variations in the color of a transparent area can cause some pixels to be transparent, and some to be opaque.

See the discussion of the Alpha Channel Mask Editor elsewhere in this document for more information about setting the transparency for images with alpha channel transparency.

Transitions

NOTE: In addition to the transitions available in the internal Transitions function of PNG/MNG Construction Set, you can access forty more transitions with the Transitions #2 and Transitions #3 plugins, available from Alchemy Mindworks.

The Transitions function in the Edit menu will create animated transitions between multiple still images. These can range from simple wipes and dissolves to complex special effects.

You can add as many images as you like to the Transition function and have it create a final animated MNG file which contains all the frames of the effects you've chosen. Here are a few examples of the Transition function at work – the permutations available to move between pictures are diverse.

Several examples of the effects available in the Transitions function of PNG/MNG Construction Set. These image fragments have been drawn from the Alchemy Mindworks Indecent Images CD_ROM. The source graphics are copyright © Christies Images.

To create a transition, select Transitions from the Edit menu of PNG/MNG Construction Set. Click on the Add button. A File Open dialog will appear to select source image files. You can build a transition from any combination of the file types PNG/MNG Construction Set recognizes, including PNG, JPG and BMP.

You can click and drag selections around the Transitions list box.

Once you have added the source images for your transition, select a default transition. Here's what the transition types do:

- Chunks:

  Your images will dissolve in a sequence of chunks which increase in size.

- Dissolve:

  Your images will fade from one graphic to the next.

- Interlace:

  Your images will dissolve in a complex interlace of pixels.

- None:

  Your images will transition from one graphic to the with no animation. This is a quick way to make slide shows.

- Radar:

  Your images will transition from one graphic to the next in a pie-shaped segment that gradually expands.

- Raster:

  Your images will transition from one graphic to the next as a sequence of bars. There are horizontal and vertical rasters available.

- Roll:

  Your images will transition from one graphic to the next by rolling one image above the previous one. This looks like paper emerging from a photocopier.

- Sandstorm:

  Your images will transition from one graphic to the next in a random scattering of pixels.

- Spinners:

  Your images will appear to rotate on a moving sign. There are four spinner options, one for each direction.

- Split:

  Your images will transition from one graphic to the next by splitting into two. There are horizontal and vertical splits available.

- Tile:

  Your images will transition from one graphic to the next in a random scattering of square tiles.

- Wipe:

  Your images will transition from one graphic to the next by wiping. There are four wipe options, one from each direction.

There are several other controls in the Transitions dialog:

- Delay:

  This defines the number of hundredths of a second between images in your transition. Increase this value to slow your animation down.

- Pause:

  This defines the delay for images between transitions. It should typically be somewhat longer than Delay.

- Dither:

  Enable this item to have your transition images dithered to the selected palette. Disable this item to have them remapped. Dithering will provide somewhat better color management, especially for photorealistic subjects, at the cost of some image resolution.

- Custom Palette:

  Enable this item to have a superpalette created for your transition. Disable it to use the selected palette for your final animated transition.

- Anti-alias:

  Enable this item to have your transition images anti-aliased. See the discussion of anti-aliasing elsewhere in this document for more about this feature.

- True Color:

  Enable this item to have the Image chunks in your final animation handled as true-color graphic, with no remapping or dithering. This will unquestionably result in a more attractive animation, albeit with the likelihood that your final MNG file could get a tad enormous.

- Palette:

  This defines the default palette from which the matt color for your transition will be drawn, and to which it will be dithered or remapped if you don't enable Custom Palette. Note that while this palette selector supports palettes with fewer than 216 colors, some of the transition effects will look very strange indeed.

- Matt Color:

  All the frames in a transition must have the same dimensions in pixels. If you attempt to create a transition with source images of various dimensions, your final transition will have the dimensions of the largest of your source images, with the smaller images insert into a matt of a color defined by this item.

- Advanced:

  The Advanced button will provide you with access to a number of controls to fine-tune parameters of the Transitions dialog. It's a good idea not to mess with these unless you understand what they're up to.

  - Sandstorm Chunk Size:

    This is the number of points that will be painted per frame for the Sandstorm transition. Increasing this value will create fewer frames, but with coarser action.

  - Horizontal Step:

    This is how far transitions which move horizontally will shift in one frame. This affects effects like Horizontal Wipe and Horizontal Raster.

  - Vertical Step:

    This is how far transitions which move horizontally will shift in one frame. This affects effects like Vertical Wipe and Vertical Raster.

  - Chunk Spacing:

    This is the distance in pixels between the expanding tiles in the Chunks transition.

  - Raster Size:

    This is the thickness in pixels of the lines in the Raster transitions.

  - Tile Size:

    This is the size in pixels of the tiles in the Tile transition.

  - Tile Chunk Size:

    This is the number of tiles that will be painted per frame for the Tile transition. Increasing this value will create fewer frames, but with coarser action.

  - Dissolve Step Size:

    This is the amount of blending per frame in the Dissolve transition. Increasing this value will produce dissolves with fewer steps but with coarser action.

  - Radar Start Angle:

    This is the angle at which the Radar effect begins, in degrees.

  - Radar Step Angle:

    This is the amount by which the Radar effect moves per frame, in degrees.

NOTE: The Transitions function is capable of creating some alarmingly large MNG files. Complex transitions may add many new frames to your animation, in addition to those of your source images. In creating transitions with PNG/MNG Construction Set, start with a small number of images with modest pixel dimensions. Supercompressor will make some transition MNG files markedly smaller – and others will just laugh at it.
The Transitions function does not have a finite upper limit for either the size or the dimensions of the images it can support. However, if you feed it a large number of images with lots of pixels, it will probably create a final MNG file that's too big to be of much use. It might also run out of memory in extreme cases.

Underlay

The Underlay function will allow you to create animated MNG files in which one frame appears to be a constant background behind your animation. It's the conceptual opposite of the Overlay function. As with Overlay, the Underlay function is extremely effective, but it does require some forethought to use correctly.

It also helps to understand what it's really up to.

While the example underlay shown here seems to have its grid appearing below the spinning world animation, all that this graphic really consists of is the globe painted over the grid in every frame. As the grid doesn't move and it's never overwritten, it appears to remain motionless and unchanging while the globe spins above it.

You can use this technique with any still image and a suitable animated foreground.

To create an underlay:

1. Build your source MNG file with the still image to be overlaid followed by all the frames of the animated foreground. In fact, the position of the still image relative to all the other images in your MNG file is immaterial, but putting it at the top of the list of chunks makes it easy to keep track of.

2. Select all the chunks in your MNG file by clicking on the Tag All button in the PNG/MNG Construction Set tool bar.

3. Click once on the chunk that will be your still underlay – this will be the first Image chunk in this example. The selection caret should appear.

4. Select Underlay from the Chunk menu. Click on Preview to see what your underlay looks like, or on OK to create a completed underlay animated MNG file.

There's an important catch in the foregoing. The images of the animation to appear above your background should have their backgrounds made transparent before you select the Underlay function. In the case of the small example underlay shown here, this has allowed the globe to appear without a rectangular background, which would otherwise have obscured the background grid.

The Underlay function cannot be used with MNG files having images which use alpha-channel transparency.

It's worth noting that Underlay only affects those animated frames which are selected. Any frames which are not selected will be copied un-underlaid to the new MNG file being created. You can use this feature to underlay more than one image, or to create underlays which appear and disappear over the course of the complete animation.

Undo

The Undo item of the Edit menu will undo the most recent change you've made to the file in the uppermost document window. This item will be disabled if there's nothing to undo.

Upgrade Manager

The Upgrade Manager function can be found in the Help menu of PNG/MNG Construction Set. It will assist you in keeping your installation of PNG/MNG Construction Set up to date.

Your computer will need access to the Internet to use the Upgrade Manager.

The Upgrade Manager functions are:

Policy: This item will open a document outlining the current Alchemy Mindworks upgrade policy. Please be sure you read it before you use the other Upgrade Manager features.

Upgrade Registration Now: This item will open the Alchemy Mindworks secure server e-commerce page to let you purchase a registration upgrade – and anything else you like the look of while you're in a spending mood. Note that you'll require your registration name to complete your registration upgrade. See the About dialog in the Help menu of PNG/MNG Construction Set – it appears right after the text Registered To.

Download Upgrade: This item will access the software version database on the Alchemy Mindworks web server and tell you if your software is out of date. In the event that there's a downloadable upgrade available, it will provide you with a link to the appropriate installer. Note that while this function sends some information about your software to the Alchemy Mindworks web server – it pretty much has to if it's to check the version of your installation – there's nothing particularly sneaky going on, and none of the information that's exchanged with our server will be logged, recorded or distributed to third parties.

View

The View function of the PNG/MNG Construction Set Chunk menu can also be accessed through the View button in the tool bar. Select View to view a still image or an animation. The View mode will display all the animated elements of your MNG files, including transparency.

Click with your right mouse button to exit a View window.

If you have the View Mode Tool Bar item enabled in Setup, the View window will appear with a set of buttons below the animation it displays. These behave as follows:

Open: Play: Starts a previously-paused animation.

Close: Closes the View window.

Pause: Pauses a running animation.

Rewind: Pauses the current animation and rewinds it to its first Image chunk.

Step forward: Pauses the current animation and steps forward by one Image chunk.

Step backward: Pauses the current animation and steps backward by one Image chunk.

Note that if you have the View Mode Tool Bar option enabled, the minimum width of the View window will be expanded to allow all the tool bar buttons to be displayed. Your animation may appear in a larger area than it actually occupies.

This document and all the other documentation included with PNG/MNG Construction Set is copyright © 1995 – 2009 Alchemy Mindworks. It may not be reproduced in whole or in part or transmitted in any form save as a component part of the PNG/MNG Construction Set software without the explicit written permission of the copyright holder. Unauthorized use of this document or any portion thereof may result in severe criminal and civil penalties. Alchemy Mindworks accepts no responsibility for any loss, damage or expense caused by your use of the information in this document, however it occurs. This product is marketed under license from Alchemy Mindworks Corporation.