|
|
|
GIF Construction Set Professional is a GIF animator. At its simplest level, it can assemble the source images of an animation sequence into an animated GIF file, suitable for use on a web page. This is a bit like the observation that at its simplest level, an XJS Jaguar can be useful for picking up a few groceries. GIF Construction Set Professional represents the state of the art of GIF animation software. Among its many features are:
There is, of course, a lot more to GIF Construction Set Professional. However, the software has been structured to let you use as much or as little of it as you need, without having the rest of it get in your way. GIF Construction Set Professional has a very short learning curve. It’s worth noting that GIF animation as it appears on the web is something of a compromise. The GIF format was not really designed for this function, and it has been pressed into service for use on the web more through expediency than because of a perfect fit to the requirements of the Internet. While GIF Construction Set Professional will usually manage to shield you from the vicissitudes of the GIF format, you will need to know a few things about the nature of GIF files to make your animations behave themselves. In reading this document, keep in mind that it’s a tutorial, rather than an exhaustive reference. It’s intended to help you get up to speed with GIF Construction Set Professional as quickly as possible. To this end, it deliberately omits a fair bit about the software’s more esoteric features. You can find an encyclopedic discussion of absolutely everything there is to know about GIF Construction Set Professional in the Reference document installed with this software. Secondly, if you’re in breathless hurry to start generating animations, you might want to check out the Quick Start document installed with GIF Construction Set Professional. It’s a still more abbreviated tutorial, ideal for people who regard reading extensive documentation as a character flaw. You know who you are. If you're really new to graphics, be sure to read the Introduction to Graphics document installed with GIF Construction Set Professional. It will familiarize you with the concepts upon which this software is based, and save your walls from considerable potential damage caused by you banging your head against them. This document will make a few references to configuring GIF Construction Set Professional. While it’s worth keeping in mind the software characteristics which can be configured, you needn’t actually change anything to use this tutorial. There’s a complete discussion of the configuration options for GIF Construction Set Professional in the Reference document.
Something Really Important Here’s the single most important thing you need to know about GIF files. If you read nothing else in the documentation for GIF Construction Set Professional, read this. An image as it’s seen by your eye, and by things like digital cameras, scanners and most decent imaging software, is represented as "true color." True-color images have a virtually unlimited number of available colors from which to draw. In a computer’s sense, a virtually unlimited number is 16,777,216 colors, which is close enough to infinity for the purpose of this discussion. These "true-color" images are also referred to as "24-bit" images, because two raised to the power of 24 is 16,777,216. Somewhere in the heady days of your youth there no doubt lurks a prematurely-bald highschool mathematics teacher who would find this highly significant. Because the GIF format harkens back to the adolescence of personal computers, wherein only rich people could afford systems with four megabytes of memory, GIF files can support a maximum of 256 colors, down somewhat from 16,777,216. In order to represent a true-color image in a GIF file, some way must be found to do so using no more than 256 colors. This is from whence almost all the problems with GIF files on the web arise. There is a way to squeeze a true-color image into a GIF file. It involves several steps. It’s worth noting that you won’t have to do any of this yourself – GIF Construction Set Professional will handle it for you – but you might be called upon to decide which of a variety of options to tell it to select.
In creating an animation, it’s often the case that multiple true-color images, each having its own range of colors, need be squeezed into the claustrophobic back seat of the GIF format. GIF files for use on the web must apply the same 256-color palette to all the images in an animation. GIF Construction Set Professional deals with this issue by deriving the best possible palette for all the images in an animation, what is called a "superpalette." Once again, you need not know how all this works, as long as you know what it means. GIF Construction Set Professional will import images to create your animations with from most of the popular image file formats. These include GIF, PNG, PCX, BMP and JPG. The GIF format, as has been discussed, can support images having no more than 256 colors. As such, using GIF source images to build your animations is likely to confront you with the least dire color problems of the sort discussed here. By comparison, all images stored in JPG files have 16,777,216 possible colors. Using JPG files as source images can require that you be somewhat more aware of how GIF Construction Set Professional will deal with too many colors. A great deal more will be said of this later. PNG, BMP and PCX files can contain images having anywhere from two to 16,777,216 colors. If you plan to work with source images in a variety of file formats, we strongly recommend that you check out Alchemy Mindworks’ Graphic Workshop Professional software.
About Image Dimensions Bitmap or "raster" images – the type of graphics which are stored in GIF files – have dimensions which can only be expressed in pixels. A pixel is one of the colored dots that comprise a graphic. A pixel is as big as the device which displays it wants it to be. A pixel displayed on your monitor will be ablut 1/75th of an inch across. A pixel printed on a laser printer might be 1/300th of an inch across. The same graphic displayed on your monitor and printed on a laser printer will be a lot smaller in the printed output for this reason. Because it’s impossible to say how big a pixel is in an absolute sense, it’s also impossible to assign specific dimensions in inches to a graphic. You might note that a graphic occupies a two inch by three inch area of your monitor, but this is largely meaningless unless the party to whom you communicate this observation has the same brand of monitor, configured identically to yours. Some applications allow you to work with bitmapped graphics like GIF files in inches or millimeters, but this is an illusion perpetrated for the convenience of people who don’t much like the idea of objects with no fixed size. Software like this typically assumes that your graphics will be displayed at a specific resolution – that of your monitor or printer – and it calculates their image dimensions accordingly. GIF Construction Set Professional always displays image dimensions in pixels.
Inside a GIF File The most constructive analogy for a GIF file is a strip of movie film. Just as a movie is really a sequence of still images, so too is a GIF file a sequence of still computer graphics. There are several important distinctions, however:
The individual bits that make up a GIF file are called its "blocks." Each GIF file consists of several of the following blocks:
There are actually several additional types of blocks defined for the GIF format, but they’re not relevant to GIF files as they appear on the web, and they can be safely ignored for the moment.
GIF Construction Set Professional's Blocks GIF Construction Set Professional manages GIF blocks in a way which will keep you from having to deal with some of the really grotty aspects of GIF files. Specifically:
While GIF Construction Set Professional will open conventional GIF files, and it creates conventional GIF files when you save an animation, it hides any Loop and Control blocks while you’re working on an animation. This will present you with fewer blocks to keep track of – a worthy consideration if you’re juggling the elements of a complex animation – and it will obviate the possibility of getting the Loop and Control blocks of your animations in the wrong place. Users of earlier versions of GIF Construction Set should note that this differs from the way the software used to work. As will be discussed later in this document, each block in a GIF file can be edited – you can change block parameters such as the number of times a Loop block goes around or the number of pixels an Image block is offset from the upper left corner of the image area of an animation. Because an Image block includes its attendant Control block as far as GIF Construction Set Professional is concerned, editing an Image block also gives you access to all its Control block parameters. This, too, will be dealt with in greater detail shortly.
Open and View an Existing Animation The simplest thing GIF Construction Set Professional is likely to be called upon to do is to open an existing GIF animation and allow you to watch it do its stuff. There are several GIF animations included with the GIF Construction Set Professional software. The simplest of these is BALL.GIF. To open BALL.GIF:
The BALL.GIF file will open in a document window. You’ll see its Header block followed by a sequence of Image blocks, each displaying the graphic it contains. You might have to scroll the document window to see all the cells. To view the BALL.GIF animation, click on the View button in the tool bar. A window will appear with the animated ball in it. When you get tired of the animated ball – something that should occur fairly quickly unless you’re having a remarkably dull day – click in the animation window with your right mouse button to close it. The EXAMPLE2.GIF file included with GIF Construction Set Professional is another animation. You can open and view it the same way as you did BALL.GIF. Note that when you open EXAMPLE2.GIF, the document window for BALL.GIF remains where you initially opened it. GIF Construction Set Professional allows you to have as many open animation documents as you like. You can find an unlimited selection of animations on the web. If you encounter an animation you’d like to keep as you’re surfing the web, click on it with your right mouse button. A menu will appear – select Save Image As to save it to your hard drive as a GIF file. You can then open the GIF file you’ve saved in GIF Construction Set Professional, as discussed above. This works for both Netscape and Explorer.
Let's Build an Animation In creating an animation "from scratch," it’s best to think of yourself as the animation artist, and of GIF Construction Set Professional as the animation camera. It’s your responsibility to create the source images which will form the action in your animation. GIF Construction Set Professional will put them together for you. In fact, GIF Construction Set Professional will do a lot of animating too, but we’ll deal with this later. For the purpose of this exercise, we’re going to create an animation from a sequence of cells provided with GIF Construction Set Professional. The source cells are stored in the files CELL0.GIF through CELL7.GIF. Note that while this exercise will use source images stored in the GIF format, you can build animations from JPG, BMP, PCX, PNG and TGA files as well. The easiest way to build an animation is to use GIF Construction Set Professional’s "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 GIF file.
The Animation Wizard dialog behaves a bit like Windows Explorer. It includes three panels. The leftmost panel is a navigation tree to select the folder on your hard drive where your source images reside. The center panel will display a list of all the available image files in the folder you select with the left panel. The right panel will display the list of images you've selected to build your animation with – it will be empty when the wizard first appears. As an aside, you can return all the configurable items of the Animation Wizard to their default state by holding down the Shift key when you click on the magic wand button in the GIF Construction Set Professional tool bar. If you experimented with the wizard before you got to this tutorial, you might want to do this now to make sure it's set up properly. The Animation Wizard includes a fair number of configurable settings, but they default to values which will create attractive animations without any immediate need to adjust them. The discussion of the Animation Wizard in the Reference document accompanying this application will describe all its features in detail, once you've mastered its basic operation. The first time you open the Animation Wizard, it will point itself at the parent directory into which you installed GIF Construction Set Professional. Notice that the GIF Construction Set Professional folder in the left navigation tree panel is open. You should see five files listed in the center panel, the first of which will be BALL.GIF. The source images for this example reside in the html folder below the GIF Construction Set Professional parent directory. Locate the html entry immediately below the GIF Construction Set Professional item in the left panel and click on it. The contents of the center panel will change, showing you the BALL.GIF graphic at various degrees of rotation.
You need to select the files CELL0.GIF through CELL7.GIF in the center panel. To do this:
If you make a mistake in selecting your source files, right-click in the middle panel and select Select None from the menu that appears to unselect all the files and try again. Once you've successfully selected all eight source files in the center panel, click on the Add button in the Animation Wizard tool bar. Your selected graphics will be copied to the right panel. You're now ready to build your animation. Click on Build. You'll see the status bar move at the bottom of the GIF Construction Set Professional application window – fairly quickly, as this is not a particularly involved animation – and the Animation Wizard window will close after a moment or two. Your completed animation will appear in a new GIF Construction Set Professional document window. Click on the View button – the sunglasses button – to see it animate. Note that each animation created by Animation Wizard will be assigned a unique file name. The Save As function will let you change this to a name of your choice. It's a really good idea to name your animation files with descriptive names. 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 GIF Construction Set Professional 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 GIF Construction Set Professional.
How Transparency Works One of the reasons GIF files are used on web pages is their ability to manage image transparency. A transparent image is one in which some areas of the picture to be displayed are transparent and will allow the background color or background texture of your web page to appear. Using transparency, for example, you can create an irregularly-shaped image and have it appear as such on your web page without a rectangular frame around it. Transparency can be a bit frustrating if you don’t understand what it’s really up to. GIF files manage color through "palettes," as has been touched on earlier. This means that in a 256-color GIF file, each pixel represents a number from zero through 255, rather than a specific color. Each number is an index into the palette for the image. This means that if a pixel holds the number 10, and color number ten in the palette is white, the pixel will be white. If color number ten in the palette is bright purple, the pixel will be ugly. While funky and not a little confusing, this arrangement allows GIF files to store pictures using less file space than would otherwise be the case. A transparent GIF file is one in which one of the available palette colors has been defined as being transparent. For example, if color number ten were to be defined as transparent, any pixels which were painted in color ten would not appear when the image was displayed. This is where transparency can get a bit peculiar. If color number ten is white and you define color number ten as being the transparent color, all the white areas will become transparent. At least, this will be true if all the white areas in your graphic are actually painted in color number ten. If color number eleven happens to be white as well, and some of the white areas are painted in color number eleven, only some of the white areas in your picture will ultimately display as transparent. Pictures which have been dithered to get them into the available color depth of a GIF file often include areas of alternating pixels of very similar colors. Attempting to apply transparency to such an image may leave you with a pattern of dots overlaying your transparent areas. The GIF format allows only a single transparent color per image. This is the sort of stuff to make grown men weep, heroes quaver and little old ladies pull Uzis out of their oversize tote-bags to kill their poodles with. As a rule, transparency isn’t usually workable in photorealistic GIF images unless you edit the images with a paint package to tidy up any stray colors that might be lurking about in your otherwise transparent areas. If you create a transparent GIF file with GIF Construction Set Professional and view it only to find that not everything you don’t want to see is in fact transparent, some retouching is in order. GIF Construction Set Professional has a built-in paint function which is exceedingly handy for this, as we’ll get to presently. You should keep in mind that when a non-transparent animation is displayed by a web browser, each frame overwrites the previous one. In displaying a transparent GIF file, some areas of the image being painted will not overwrite the previous images, as they’ll be transparent. This can result in animations which seem to leave bits of themselves behind. To avoid this, each image of an animated GIF file must be overwritten by the background color or texture of your web page before it is replaced by the next image. This is called "removing by background." We’ll see how this is enabled shortly. It’s worth keeping in mind that not all applications which display GIF files handle transparency. If you want to view a transparent animated GIF file correctly, use GIF Construction Set Professional, Graphic Workshop Professional or your web browser. Finally, when GIF Construction Set Professional displays a transparent GIF file, it does so against a background of the background color for the GIF file in question. The background color is defined in the Header block for each GIF file – we’ll look at editing the Header block parameters in a moment. This differs from the way transparency is handled by a web browser, which will ignore the background color of a GIF file and display it against the background of your web page. In working with transparent GIF files in GIF Construction Set Professional, it’s a really good idea to set the background color to something really ugly that you’d never use in your images. At the very least, it should contrast markedly from the color of the areas you wish to make transparent. Having done so, it will be easy to spot which areas are really transparent, and which are just painted in a color similar to the color you’ve defined as transparent. We’ll look at how to add transparency to existing GIF files later in this document.
Editing the Header Block You can edit the parameters of most of the blocks in a GIF file using GIF Construction Set Professional. The exception is a type of block called an Application block, something which has not been touched on thus far. Application blocks are what GIF files use to hold mysterious contents which only certain applications know how to work with. GIF Construction Set Professional will refuse edit these blocks. To edit a block, double-click on it in the document window for its animation. The appropriate editor window will appear.
If you double-click on the Header block for the BALL.GIF animation, you’ll see the Header block editor. There’s not all that much you’ll want to do to the Header blocks of animations as a rule. Here’s a quick overview of the controls and what they do.
Editing Image Blocks Each frame of your GIF file is represented as an Image block. If you double click on an Image block in the document window for an animation, an Image block editor will appear. Seasoned users of GIF Construction Set will note that the Image block editor also includes a Control block editor bolted onto the side.
Editing Comment Blocks Comment blocks are the only other block type you’re likely to encounter in working with GIF files for the web. You’ll find a Comment block at the end of the list of blocks for BALL.GIF. If you double click on a Comment block, a Comment block editor will appear. You can modify the text in a Comment block by editing the contents of this dialog. The Format button changes the font used to display the text in GIF Construction Set Professional’s Comment editors. It does not affect how it will appear in other applications which might display your comment blocks. GIF Construction Set Professional may append one or more comment blocks to the GIF files it writes. While these are discussed in greater detail elsewhere in the documentation for the software, there are two specific Comment blocks you might want to keep in mind:
Adding Blocks to a GIF File If you create animations through Animation Wizard, chances are all the blocks that you’ll need in your GIF files will be in place as soon as Animation Wizard stops waving its wand and casting its spells. There are instances in which you might want to add blocks to a GIF file by hand, however. Specifically, you can use GIF Construction Set Professional’s block insertion functions to add still more images to an animation, and to add Comment blocks to a GIF file. In fact, the block insertion function also supports a third type of blocks, called "Plain Text" blocks. Plain Text blocks are not supported by all web browsers, and should not be used if you’re creating GIF files for use on the web. When you see text in a GIF file, you’re really looking at a graphic which looks like characters. Let’s insert a Comment block into BALL.GIF. If you click on the Header block of BALL.GIF, you’ll find that a blue or red line will appear along the bottom of the block. 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 block into a GIF file with GIF Construction Set Professional, the new block will appear after the block which currently has the insertion caret. The insertion caret will appear on the block you’ve most recently clicked on. With the insertion caret visible in the Header block, you can insert a block after the Header block either by:
or
In either case, a menu will appear. Select Comment as the type of the new block to be inserted. A Comment block will appear after the Header block in BALL.GIF. You can edit the text in your new Comment block by double clicking on it, as discussed earlier. The other common use of the Insert Block function is inserting Image blocks into an existing GIF file. This behaves the same way as Comment block insertion, save that you will be prompted for a file name to read your new image from, and most likely with a Palette dialog once your new image has been read. This latter dialog will allow you to tell GIF Construction Set Professional how to deal with an image having a color palette which differs from that of the GIF file you’re trying to insert it into. Palettes will be discussed in greater detail later in this document. Consult the Reference document for more about the options in the Palette dialog.
Deleting Blocks from a GIF File You can delete any block except the Header from a GIF file. Click on the block in question to select it and click on the minus button in the tool bar, or hit the Del key on your keyboard. Note that all the selected blocks in the GIF file in the uppermost document window will be deleted by the Delete function. The number of currently selected blocks is displayed in the status bar at the bottom of the GIF Construction Set Professional application window. If you delete a block 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, GIF Construction Set Professional will warn you if you’re about to delete more than one block.
Adding Transparency to a Still GIF File GIF files converted from other formats or saved from paint applications typically do not include transparency information. If you need a transparent still GIF file, you can enable transparency for an existing graphic with GIF Construction Set Professional. Here’s how to do it:
You can save your transparent GIF file through the Save or Save As items of the File menu.
Supercompressing a GIF File In creating GIF animations for the web, it’s important to make the final GIF files that are referenced by your HTML documents as small as possible. The unspeakable, breathtaking excellence of your animations won’t impress anyone if they lapse into comas while waiting for your GIF files to download. In some cases, it’s possible for sufficiently sneaky software to squeeze some unnecessary pixels out of your animations and in so doing create smaller GIF files. The sufficiently sneaky software is the Supercompressor function in GIF Construction Set Professional. It’s important to keep in mind what Supercompressor is really up to. All GIF files are compressed. Supercompressor attempts to meddle with the blocks in your GIF files to make them more compressible. In some cases it can do quite a bit in this respect, and in others it’s wholly ineffective. If there’s nothing to squeeze out of your GIF file, Supercompressor will not make it any smaller. Supercompressor makes GIF files smaller by doing one or more of the following to them:
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’s will often be very, very difficult to edit. The Supercompressor will not perform pruning or redundancy compression on GIF files which have one or more Image blocks with transparency enabled. To use the Supercompressor, open a GIF file in GIF Construction Set Professional and select Supercompressor from the File menu. Note that you can disable any compression types you don’t want to use, and Supercompressor will disable any compression types it decides are inappropriate for your GIF 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 GIF file, it will tell you so and the OK button will not be enabled.
Investigating Banners There are a number of enormously fun toys in the Edit menu of GIF Construction Set Professional, including Banners, Transitions, Wide-Palette GIF, LED Signs and Spin. To a large extent, these are beyond the scope of this tutorial. However, you might want to have a quick look at the simplest of them, Banners, to get a feel for what you can do with them. The Banners function 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 GIF Construction Set Professional. 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:
With the exception of Teletype and Scanners, 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.
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 GIF Construction Set Professional document window. You can save it to disk by selecting Save As from the File menu.
GIF Construction Set is a powerful and exceedingly flexible application for creating web page graphics. To make the most of it, be sure to check out the Reference document and the other documentation files included with this package. This document and all the other documentation included with GIF Construction Set Professional is copyright © 1995 – 2007 Alchemy Mindworks. It may not be reproduced in whole or in part or transmitted in any form save as a component part of the GIF Construction Set Professional 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.
|
|
|
|