Codec adapter
j2k-metal exposes Apple Metal-backed JPEG 2000 / HTJ2K decode and encode-stage adapter APIs.
cargo add j2k-metal
Metal JPEG2000 Rust
Metal JPEG2000 Rust
J2K provides Apple Metal adapter crates for supported JPEG 2000 / HTJ2K device-output and encode-stage paths, plus supported coefficient-domain stages of JPEG-to-HTJ2K transcode workflows on macOS.
Release status: j2k 0.8.0 is published on crates.io; see the release policy for support details.
JPEG input adapter
j2k-jpeg-metal provides Metal-backed JPEG decode surfaces and selected baseline encode paths.
cargo add j2k-jpeg-metal
Transcode adapter
j2k-transcode-metal accelerates supported coefficient-domain stages of JPEG-to-HTJ2K transcode on macOS; packetization remains outside those transform stages.
cargo add j2k-transcode-metal
Supported shape policy
Metal support is selective. Explicit Metal requests are strict and return unsupported-request errors for shapes outside the adapter's supported path.
Metal adapters sit under the same codec support boundary as the public crate: JPEG 2000 Part 1, JP2 still-image files, HTJ2K Part 15, and JPH still-image files. CPU remains the portable correctness baseline for unsupported or unbenchmarked shapes.
Current public benchmark evidence is in docs/benchmark-evidence.md. Metal performance claims should cite hardware, commands, supported shape, skipped rows, and publication_eligible=true from the benchmark/adoption tooling.