The BMP files in the Star Trek 25th Anniversary store 2D graphics for use anywhere in the game. The file format is quite simple: it starts with two 16-bit little-endian unsigned integers that tell you the x and y coordinate for the center of mass of the sprite, and then two more 16-bit little-endian unsigned integers for the x and y resolution of the image. After that it is a stream of bytes which are the palette index for each pixel (indexing into the PALETTE.PAL palette for most images except those viewed on the bridge during space combat). The color index 0x00 is reserved for transparent pixels. This format includes all level background images and character sprites.
You can find a download of all of the BMP files extracted and converted to png (using PALETTE.PAL, even when that is the wrong choice--you'll know when!) in this zip file.
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