Plan 9 Image
From Just Solve the File Format Problem
The Plan 9 image format is used in the Plan 9 from Bell Labs operating system. It does appear to have been used in Bell Labs before Plan 9's creation, but no name was given to it.
A Plan 9 image file can be either compressed or uncompressed. The uncompressed format starts with 5 groups of 12 bytes indicating image information in plaintext. The compressed format starts with the string compressed\n, then 7 groups of 12 bytes indicating image information in plaintext. The remainder of the image format is the pixel data itself, formatted as determined by the previous info, either uncompressed, or compressed using LZ77, respectively.
