GIF files provide an easy way to export drawings and simple animations for use in web pages. Standard GIF files are simply compressed bitmaps.
An animated GIF (sometimes referred to as a GIF89a) offers a simple way to export short animation sequences. Flash optimizes an animated GIF, storing only frame-to-frame changes.
Flash exports the first frame in the movie as a GIF, unless you mark a different keyframe for export by entering the frame label #Static. Flash exports all the frames in the current movie to an animated GIF unless you specify a range of frames for export by entering the frame labels #First and #Last in the appropriate keyframes.
Flash can generate an image map for a GIF so buttons that link to URLs in the original movie continue to function as links in the image. Place the frame label #Map in the keyframe in which you want to create the image map. If you don't create a frame label, Flash creates an image map using the buttons in the last frame of the movie. To create an image map the $IM template variable must be present in the template you select. See Creating an image map.
Use the controls in the GIF panel of the Publish Settings dialog box to change the following settings:
Dimensions Sets the size of the exported bitmap image to the number of pixels you enter in the Width and Height fields. If you turn on Match Movie, the entries in the Width and Height fields have no effect and Flash makes the GIF the same size as the movie. Flash ensures that the size you specify always has the same aspect ratio as your original image.
Playback Determines if Flash creates a static image, or an animation. Click Static to export a still image. Click Animated to export an animated GIF. If you choose Animated, choose either Loop Continuously, or enter a number of repetitions.
Options Specify a range of appearance settings for the exported GIF.
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Optimize Colors removes any unused colors from the color table of a GIF file. This can reduce the size of a GIF file by 1000-1500 bytes with no sacrifice in image quality. It does, however, cause a small increase in the memory requirements. Note that this option has no effect with an Adaptive palette. |
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Smooth enables or disables anti-aliasing in the exported bitmap. Smoothing produces a higher-quality bitmapped image. Text display quality is poor without anti-aliasing. However, a halo of gray pixels may appear around an anti-aliased image placed on a colored background. Export without smoothing if a halo appears, or if you are creating a transparent GIF that will be placed over a multicolored background. Turning this option off makes GIF files smaller. |
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Interlace makes the exported GIF display in a browser incrementally as it downloads. An interlaced GIF provides the user with basic graphic content before the file has completely downloaded and may download faster over a slow network connection. Do not interlace an animated GIF. |
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Dither Solids applies dithering to solid colors as well as gradients and images. See the definition of dithering that follows. |
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Remove Gradients converts all gradients fills in the movie to solid colors using the first color in the gradient. Gradients increase the size of a GIF and often are of poor quality. When using this option you must choose the first color of your gradients carefully to prevent unexpected results. The default is false. |
Transparent Determines how the background of a movie and alpha (transparency) settings in Flash are converted to GIF. Choose one of the following options from the pop-up menu:
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Opaque makes the background of the movie opaque. |
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Transparent makes the background transparent. |
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Alpha makes all the colors below the threshold alpha value completely transparent (invisible). Colors with alpha values above the threshold are left as they are. Enter a value between 0 and 255 in the Threshold box to the right. A value of 128 corresponds to 50% alpha. |
Dither Enables or disables dithering and specifies the method. Dithering displays pixels of a range of similar colors to simulate colors not available in the current palette. With dithering off, Flash replaces colors not in the basic color table with the solid color from the table that most closely approximates the specified color; not dithering can produce smaller files, but check the results to see if the colors are satisfactory. Dithering can help if a transparent image contains artifacts. Dithering increases the files size. Choose from the following dithering options:
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None disables dithering. |
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Ordered provides good quality dithering with the least possible file size increase. |
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Diffusion provides the best quality dithering but increases file size and processing time more than Ordered dithering. It also only works with the Web 216 color palette selected. |
Palette Type Defines the color palette to use for the image. Choose from the following options:
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Web 216 uses the standard 216 color browser-safe color palette to create the GIF image. This provides good image quality and the fastest processing on the server. |
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Adaptive analyzes the colors in the image and creates a unique color table for the particular GIF. This creates the most accurate color for the image but the resulting file size is larger than a GIF created with the Web 216 palette. You can reduce the size of a GIF created with an adaptive palette by decreasing the number of colors in the palette (see the Max Colors option that follows). An adaptive palette works best for systems displaying thousands or millions of colors. |
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Web Snap Adaptive is the same as the Adaptive palette option except that it converts close colors to the Web 216 color palette. The resulting color palette is optimized for the image, but when possible, Flash uses colors from Web 216. This produces better colors for the image when the Web 216 palette is active on a 256-color system. |
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Custom lets you specify a palette that you have optimized for the current image. This provides the same processing speed as the Web 216 palette. To use this option you must be familiar with creating and using custom palettes. To choose a custom palette, click the button labeled with the ellipsis (...) to the right of the Palette box at the bottom of the dialog box and select a palette file. Flash supports palettes saved in the ACT format. This is the same format exported by Macromedia Fireworks and other leading graphics applications. |
Max Colors Sets the number of colors used in the GIF image. Choosing a smaller number of colors can produce a smaller file, but may degrade the colors in the image. You can specify a value for the maximum colors only when you have selected Adaptive or Web Snap as the Palette Type option.