What is a PGM file?
PGM files, also known as Portable Graymap, is a grayscale image and is one amongst the many defined in the Netpbm project. Users can store these images in two forms, either in plain text or binary. Plain text format can contain only one picture, whereas the binary PGMs can hold multiple ones. You can differentiate between the two by looking into their header. If it is the former, it will have the string “P2”, whereas the latter one will have “P5” instead.
These files can either be encoded with one or two bytes (8 or 16 bits) per pixel and contains a header and various number grids representing different shades of the color gray. The number ‘0’ defines black, whereas ‘65536’ represents white. It belongs to the raster image category Jef Poskanzer is the developer credited with its discovery.
How to Open PGM Files
How to Make PGM Files
Exact steps for creating PGM files will vary by program and operating system. Download one of the above listed programs and you should be able to follow typical procedure for opening files or creating files from the File menu. Typically you will select File > Open or File > New and continue through the prompts. Some programs may follow a different procedure for either creation or opening of files.