QOI is a new losless RGB(A) image format that provides a very simple and fast encoding and decoding algorithm while having comparable compression performance to PNG. It does straightforward integer manipulation only and has a fully byte-aligned memory structure making it exceedingly suitable for low-latency and low-CPU use.
Its specification and reference implementation are completely open, and its simplicity allows it to be described in a single-page PDF document (see URL).

QOI source code (C): https://github.com/phoboslab/qoi
QOI implementation in Rust: https://github.com/aldanor/qoi-rust