My Unofficial CR2 File Structure says:

Compressed files use zlib compression.

Of course, gzip is based on zlib compression but most file compression/decompression software these days supports this compression (WinZip, StuffIt, etc.).   WinZip and StuffIt do the decompression but use their own compression algorithms in that direction.  Penguinisto's script should get you going. :)

C makes it easy to shoot yourself in the foot. C++ makes it harder, but when you do, you blow your whole leg off.

 -- Bjarne Stroustrup

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