PBM
Also known as: Portable Bitmap, .pbm file, Netpbm bitmap
PBM (Portable Bitmap) is the black-and-white member of the Netpbm family. It stores a 1-bit image — each pixel is simply on or off — in a deliberately simple format that is easy for programs to read and write.
- Netpbm bitmap format for black-and-white images
- Has both ASCII and binary variants
- Pairs with PGM (gray) and PPM (color)
How PBM works
PBM holds only black-and-white pixels with no shades of gray or color. It comes in a human-readable ASCII variant and a compact binary variant, both very simple to parse.
It is the bitmap tier of Netpbm, which also includes PGM (grayscale) and PPM (color). The trio is popular as an intermediate format in image-processing scripts.
Using PBM files
PBM is a working format, not a delivery one. Netpbm and many editors read it; convert to PNG when you need a small, widely compatible file to share.