- Extension
- .pgm
- .fax
- Format
- Binary
- Binary
- Category
- Raster Image
- Fax
- Developer
- Jef Poskanzer
- ITU-T
- Description
- A PGM file is a grayscale image file saved in the portable gray map (PGM) format and encoded with one or two bytes (8 or 16 bits) per pixel. It contains header information and a grid of numbers that represent different shades of gray from black (0) to white (up to 65,536). PGM files are typically stored in ASCII text format, but also have a binary representation.
- This format is used to compress TIFF images when sending them via fax machines. This format helps reduce the data transmission time. Group 3 eliminates redundant data during compression in order to reduce file size. The standard 10:1 compression ratio may be increased to the user's preferences, but it can lead to a significant loss of image quality.
- MIME Type
- image/x-portable-graymap
- application/vnd.fax
