.ppm File — Portable Pixmap

PPM (Portable Pixmap) is a color image format in the Netpbm family, storing uncompressed RGB pixel data with a minimal header. PPM files can be written in ASCII text (P3 format) where each RGB value is a decimal number separated by whitespace, or raw binary (P6 format) for more compact storage. The header consists of just the magic number, image dimensions, and maximum color value. This extreme simplicity makes PPM trivial to generate from any programming language — creating an image requires just writing a text header followed by RGB values. PPM is extensively used in computer science courses for teaching image processing, computer graphics, and file I/O concepts. Scientific computing and image research also use PPM as a simple interchange format. The Netpbm toolkit provides hundreds of command-line tools for converting between PPM and other formats, applying filters, and processing images in Unix pipelines. While PPM files are very large compared to compressed formats, their simplicity and lack of dependencies make them invaluable for quick image generation in scripts and educational contexts.