JPEG 2000 libraries for Rust

The image crate doesn’t support JPEG 2000. Two crates fill the gap:

• jpeg2k is a safe wrapper of OpenJPEG. It decodes everything OpenJPEG decodes, supports reduced resolution and region decoding, and converts to image::DynamicImage. It builds OpenJPEG from source (C compiler needed) or links a system copy.
• hayro-jpeg2000 is a pure-Rust decoder written for the hayro PDF renderer. No C code and no unsafe (with the simd feature off), no_std compatible, and it registers itself as a decoding hook for the image crate. It produces 8-bit output and doesn’t encode.

Neither crate is a full encoder. To write JPEG 2000 from Rust, call OpenJPEG through openjpeg-sys or run opj_compress.

• hayro-jpeg2000 hayro-jpeg2000 is a memory-safe, pure-Rust JPEG 2000 decoder. How to add it, decode JP2 and J2K files to 8-bit pixels, convert to PNG with the image crate.
• jpeg2k jpeg2k is a safe Rust wrapper of OpenJPEG for loading JPEG 2000 images. How to add it, convert JP2 to PNG with the image crate.