After much trepidation and *far* more work and proofreading than we initially expected, we have written a massive deep-dive into how JPEG files work, including showing you how to build a decoder and encoder from scratch. All of this as a result of someone shitposting here on fedi!
a free idea for someone to steal -- what if there existed a "pixel art"-like drawing program that enabled artists to paint directly with DCT basis functions? how can direct access to high-frequency macroblocks be used artistically?