Another relatively simple format, that is apparently additionally superior to PNG in terms of compression and speed, is the Quite OK Image format (QOI): https:

Another relatively simple format, that is apparently additionally superior to PNG in terms of compression and speed, is the Quite OK Image format (QOI): https://qoiformat.org/ https://qoiformat.org/ (And OT, but interesting, regarding their acronyms: P -> Q N -> O G->->I ...so close!)