XPM to PGM Converter

XPM (X PixMap) is a color image format for the X Window System, developed by Arnaud Le Hors at GROUPE BULL beginning in 1989 as the color successor to the monochrome XBM format. Like XBM, XPM files are valid C source code — each file defines the image as a static array of character strings, where the header strings specify width, height, number of colors, and characters per pixel, the color definition strings map character codes to color values (supporting X11 color names, hexadecimal RGB, and symbolic color types like 'background' and 'foreground'), and the pixel strings encode each row as a sequence of character codes that index the color palette. This ASCII art representation makes XPM images human-readable: one can often see the image content directly in the text of the source file. The format went through three revisions: XPM1 (1989, compatible with X10), XPM2 (simplified syntax), and XPM3 (1991, the current version with the static char* syntax and extended color specification). XPM was the standard format for X Window application icons, splash screens, pixmap buttons, and themed UI elements throughout the 1990s and 2000s. One advantage is the combined benefits of being a valid C source file and a color image: XPM files can be compiled into applications, edited in any text editor, processed by text tools, and version-controlled, while supporting up to 256 colors with transparency (using the 'None' color keyword). The X11 ecosystem's reliance on XPM ensures broad tool support. XPM files are handled by all X11 toolkits, ImageMagick, GIMP, and web browsers (legacy support).