j2k

JPEG 2000 Part 1 and HTJ2K Part 15 public CPU codec facade for J2K.

This crate exposes inspection, decode, encode, lossless J2K-to-HTJ2K recode, still-image container wrapping, and device-decode planning backed by the native J2K engine.

The primary adoption claim is a safe Rust public API with audited unsafe implementation boundaries and CPU as the portable correctness baseline. GPU-backed routes are optional and selected only for supported, benchmark-backed shapes; single-frame HTJ2K host-output encode stays CPU by default.

The public support boundary is raw J2K/J2C codestreams, JP2 still-image files, raw HTJ2K codestreams, and JPH still-image files. JPX / JPEG 2000 Part 2 extensions are not part of this crate's support claim unless required for standard JP2/JPH still-image correctness.

Shared encode-stage SPI types are re-exported at the crate root for CUDA, Metal, and transcode adapter interoperability. They are hidden from normal Rustdoc and are not the primary end-user encode API. Concrete device surfaces and runtime integration are provided by the j2k-cuda and j2k-metal crates.

For CPU JPEG 2000 / HTJ2K application code, use this crate directly. GPU-backed applications should also depend on the concrete adapter crate for their target backend.

Decode strictness

j2k_native::DecodeSettings::default() remains lenient for compatibility. Lenient mode may tolerate recoverable optional container metadata problems that DecodeSettings::strict() rejects. Public j2k decode outcomes report J2kDecodeWarning::LenientDecodeMode when the retained lenient default is used; callers that need fail-closed validation should construct native images with DecodeSettings::strict() or treat that warning as nonpublishable input.

Links

• API docs: https://docs.rs/j2k
• Repository: https://github.com/frames-sg/j2k
• Support policy: https://github.com/frames-sg/j2k/blob/main/docs/public-support.md