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WPM Image

Robert Jordan edited this page Mar 17, 2020 · 1 revision

The structure of this is not fully understood, or even encountered in the CatSystem2 assembly. This image format can be created from the WGC.exe in the CatSystem2 toolset.

File Structure

Data Type Value Description
char[4] "WPM" File Signature
uint32 FileLength Length of this file, excludes end padding
uint32 Width Width of the image
uint32 Height Height of the image
uint32 CompressedLength Compressed length of image data
uint32 DecompressedLength Decompressed length of image data
byte[CompressedLength] ImageData Zlib compressed image data, 1-byte blue channel
padding8 Padding Padding to 8-byte boundary of file end

Image Data

There seems to be nothing special about this image format. The uncompressed data contains just the blue channel bytes of the source image. Attempting to convert an image with all 0's in the blue channel will just yield black. There is no padding between scanlines.

It's possible using the blue channel is an old method for converting to grayscale. Because most images look fine when the blue channel is copied to red and green as well.

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