This crate provides access to OpenJPEG's JPEG2000 decoder.
Please be advised that using C code means this crate is likely vulnerable to various memory exploits, e.g. see http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-8332 for an actual example from the past.
As soon as someone writes an efficient JPEG2000 decoder in pure Rust you should probably switch over to that.
Run the examples from within the examples directory, using cargo run --example name.
Most of the code in this repository is provided under the GPL license (check out the relevant's files headers for more details).
However note that this crate links statically to OpenJPEG which has its own (permissive) license, which you can find at openjp2-sys/libopenjpeg/LICENSE (you might have to check out the git submodule first).