scascino4/dither

dither is a small command line tool written in C that applies ordered dithering to convert an image into a 16 color palette styled after old VGA graphics. Instead of smoothly blending colors the way modern displays do, it approximates shading and gradients by arranging pixels of a fixed set of colors in patterns, which is the classic way retro computers displayed images with limited color hardware. The color palette itself is defined in a source file called palette.h. If you want the tool to output different colors, you edit that file directly, then rebuild the program and run it again. There is no command line flag or configuration file for choosing colors, so changing the palette means changing and recompiling the code. Building the tool is done with a single build script, which produces an executable at build/dither. Using it is just as simple: you pass an input image and an output filename, and the tool writes a dithered version of that image using the configured palette. The README shows this with an example that converts a JPEG photo into a dithered JPEG output. The project is small in scope. It is not a general purpose image editor and it does not document options like adjustable color counts or alternate dithering algorithms. It is best suited to someone who wants a straightforward, no-frills way to give an image a retro, limited-palette look from the command line, or who wants to study a compact example of ordered dithering implemented in C.