The class supports color-mapped images where the image data contains an index into a color table or images where the image data specifies the color directly. It extends FSDefineImage by including alpha channel information for the color table and pixels in the image.
For color-mapped images the color table contains up to 256, 32-bit colors. The image contains one byte for each pixel which is an index into the table to specify the color for that pixel. The color table and the image data are compressed as a single block, with the color table placed before the image.
For images where the color is specified directly, the image data contains 32 bit color values.
The image data is stored in zlib compressed form within the object. For color-mapped images the compressed data contains the color table followed by the image data.
This tag was introduced in Flash 3.