pgmb_io, a Python code which reads and writes files in the binary Portable Gray Map (PGM) format for 2D grayscale graphics information.

There are many graphics programs, such as XV and GIMP, that can display images in this format, or translate them to other formats such as BMP, GIF, JPEG, MacPaint, X Window, and so on.


The computer code and data files described and made available on this web page are distributed under the MIT license


pgmb_io is available in a C version and a C++ version and a Python version.

Related Data and Programs:

pbmb_io, a Python code which handles the Portable Bit Map (PBM) format.

pgmb, a data directory which contains examples of binary Portable Gray Map (PGM) files.

pgma_io, a Python code which handles the ASCII Portable Gray Map (PGM) format.

ppmb_io, a Python code which handles the binary Portable Pixel Map (PPM) format.


  1. the NETPBM homepage.

Source Code:

Last revised on 29 January 2020.