Optimizing animations
You can apply optimization settings to animated images just as you do to nonanimated images. You should always optimize an animation in GIF format because GIF is the only format in ImageReady that supports the display of animated images on the Web.
Note: While you can optimize an image that includes animation in JPEG or PNG format, these formats do not support animation. The resulting Web page will display only the current frame of the animation.
In addition to the standard optimization options for GIF format, you can optimize frames to include only areas that change from frame to frame. (This greatly reduces the file size of the animated GIF.) ImageReady also applies a special dithering technique to animations to ensure that dither patterns are consistent across all frames and to prevent flickering during playback. Due to these additional optimization functions, ImageReady may require more time to optimize an animated GIF than to optimize a standard GIF.
To optimize an animated image:
- Choose Optimize Animation from the Animation palette menu.
- Set the following options:
- Bounding Box to crop each frame to the area that has changed from the preceding frame. Animation files created using this option are smaller but are incompatible with GIF editors that do not support the option. (This option is selected by default and is recommended.)
- Redundant Pixel Removal to make transparent all pixels in a frame that are unchanged from the preceding frame. This option is selected by default and is recommended. The Transparency option in the Optimize palette must be selected for redundant pixel removal to work. (See Optimization options for GIF and PNG-8 formats.)
- Click OK.
- Apply optimization settings. (See Optimizing images.)
Important: Set the frame disposal method to Automatic when using the Redundant Pixel Removal option. (See Setting the frame disposal method.)
When optimizing the colors in an animation, use the Adaptive, Perceptual, or Selective palette. This ensures that the colors are consistent across frames. (See Generating a color table.)