openjpeg を Homebrew, apk, dnf, MacPorts, Nix でインストール

プロジェクトリンク

• ホームページ
• リポジトリ

コマンドとエイリアス

• opj_compress
• opj_decompress
• opj_dump

プロジェクトの歴史

OpenJPEG comes from the Universite catholique de Louvain image and signal-processing community and is maintained as a BSD-licensed codec library plus command-line applications. The project describes its purpose plainly: provide an open-source implementation of the JPEG 2000 still-image compression standard.

The package became more significant after the reference-software recognition because JPEG 2000 has a standards-heavy ecosystem: JP2/J2K codestreams, conformance expectations, archival image workflows, medical and cultural-heritage imaging, and codec comparisons against proprietary implementations such as Kakadu.

採用の歴史

The IIIF community's 2017 OpenJPEG Improvement Project is a good adoption marker. Cultural-heritage institutions including Wellcome Library, Stanford University, the University of Michigan, the National Library of the Netherlands, and UCLA funded work to improve OpenJPEG performance, scalability, security, robustness, region-of-interest decoding, and memory footprint for production image repositories.

That adoption story is narrower than a general-purpose image library such as libpng, but deeper in archives and standards-driven imaging. OpenJPEG matters where JPEG 2000's tiling, multi-resolution access, and lossless compression properties are worth the operational complexity.

使われ方

Developers use OpenJPEG through libopenjp2 or through tools such as opj_compress and opj_decompress. The project documentation describes opj_compress as reading image formats such as BMP, PGM, PNG, TIFF, RAW, TGA, and others and writing JPEG 2000 output, while opj_decompress converts JPEG 2000 inputs such as .j2k, .jp2, .j2c, and .jpt into common image formats.

In package-manager terms, openjpeg is both a leaf tool for people converting images and a dependency for larger imaging stacks. It gives downstream software a permissively licensed JPEG 2000 implementation without requiring users to fetch a vendor SDK.

パッケージ好きにとっての重要性

OpenJPEG is the sort of dependency package that quietly decides whether an image stack can read JP2 files. It is small compared with Java or OpenLDAP, but it sits at the intersection of standards, archival workflows, security-sensitive image parsing, and optional codec support in larger applications.

The package is also notable because codec packages carry file-format risk. A JPEG 2000 decoder is exposed to untrusted binary data, so package maintainers care about upstream activity, fuzzing, CVE fixes, ABI stability, and whether downstreams bundle or dynamically link libopenjp2.

タイムライン

• April/May 2015: OpenJPEG was recognized by ISO/IEC and ITU-T as JPEG 2000 reference software.
• 2017: the IIIF community announced a funded OpenJPEG Improvement Project focused on production-readiness for digital image repositories.
• OpenJPEG 2.x: the command-line tools were renamed to opj_compress and opj_decompress, replacing the OpenJPEG 1.x image_to_j2k and j2k_to_image names.

Related projects

• OpenJPEG is related to JPEG 2000 Part 1, JP2/J2K tooling, Grok, Kakadu, IIIF image servers, ImageMagick-style image pipelines, and newer HTJ2K work where traditional JPEG 2000 performance is a bottleneck.

ソース

• https://github.com/uclouvain/openjpeg
• https://github.com/uclouvain/openjpeg/wiki/DocJ2KCodec
• https://iiif.io/news/2017/04/27/openjpeg-improvement/
• https://www.openjpeg.org/
• https://www.openjpeg.org/doxygen