pbm
What is a .pbm file?
image/x-portable-bitmap
PBM (Portable Bitmap) is the simplest Netpbm format, storing 1-bit black-and-white images as ASCII or packed binary bits after a short text header. It uses no compression and represents each pixel as a single on or off value. It is used for bilevel masks and toolchain intermediates.
How to use a .pbm file
Use an example PBM to test bilevel image parsing, bit-packing handling, and pipelines that produce or consume black-and-white masks.