PEP: A New Ultra-Efficient Compression Format for Pixel Art

PEP is a novel image compression format specifically designed for low-color pixel art (≤16 colors is optimal, up to 256 colors are supported). It uses "Prediction by Partial Matching, Order-2" compression, which is 2-10x slower than GIF, PNG, and QOI, but often compresses images 20-50% smaller than GIF/PNG (and multiple times smaller than QOI). If compressed image size matters, PEP is for you. It sits somewhere between GIF and WEBP in terms of speed/compression tradeoff. This is currently experimental, but a C header is provided for use.