NetPBM refers to a collection of command-line utilities that are used to perform various operations on raster image files. Operations include things like format conversion, image resizing and per-pixel operations.

The basic idea behind the NetPBM utilities is that you run one of the applications, listed below, and convert from some raster image format, like a JPEG file, and first convert it into a PBM file (PBM stands for "Portable BitMap"). Then, you can use one of the various filtering operations on the PBM file. After you perform whatever operation is desired, then convert the PBM file back into some other raster image file format, like JPEG.

In other words, the NetPBM utilities use a hub-and-spoke model of format conversion: everything is first converted to PBM format where it can then be manipulated, then converted back to some other raster format for use elsewhere. Note that many commonly used image manipulation tools know about PBM raster formats. PBM is a lossless raster file format, and offers only limited forms of compression.

The Specific Utilities

The following utilities comprise the entire NetPBM collection.