Freedom251 › Image Compression Software
OpenJPEG
What OpenJPEG is
OpenJPEG is a free, open-source JPEG 2000 codec written in C. It provides an API and runs on Linux, macOS, Windows, and self-hosted setups. Batch processing is available. The opj_compress utility accepts BMP, PGM, PGX, PNG, PNM, PPM, RAW, RAWL, TGA, and TIF files, then produces J2K, JP2, or J2C output. Its documentation describes both lossy and lossless workflows, using one lossless quality layer by default while also supporting compression-ratio and quality-in-dB layers. OpenJPIP adds JPEG 2000 Part 9 features such as JPIP over HTTP, image indexing, and region-of-interest requests. The project identifies OpenJPEG as JPEG 2000 Reference Software recognized by ISO/IEC and ITU-T. It uses the two-clause BSD license, allowing commercial modification with copyright retained in source or binary documentation. Version 2.5.4 is listed as latest, although the repository says it is unmaintained.
Who it suits
OpenJPEG suits developers and organizations that need JPEG 2000 encoding, decoding, or related server features across desktop, API, or self-hosted environments. Its broad input and output format support also fits batch image conversion.
What it does well
- Free under the two-clause BSD license
- Supports lossy and lossless compression
- Batch processing and API access included
- OpenJPIP supports region-of-interest requests
- Runs on Linux, macOS, Windows, and self-hosted setups
What to know first
- Repository is described as unmaintained
- Removed components have unknown working status
- Installation requires building from source instructions
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| OpenJPEG | BSD 2-clause license · commercial use allowed | Free |
As openjpeg.org lists them, read 11 Oct 2026. The maker's own page has the final word.
Verdict
OpenJPEG combines broad image-format support with JPEG 2000 compression, API access, and OpenJPIP features. The stated unmaintained repository status is an important consideration for deployment planning.
Facts from OpenJPEG's own pages
- API access
- Yes · openjpeg.org, 24 Sept 2026
- API stability
- The project says it strives to provide a stable API/ABI and exposes a limited subset of functions. · github.com, 11 Oct 2026
- Batch processing
- Yes · openjpeg.org, 24 Sept 2026
- Build
- The installation documentation points users to build and installation instructions in the source tree. · github.com, 11 Oct 2026
- Compression
- The opj_compress program converts supported image files to JPEG 2000 files. · github.com, 11 Oct 2026
- Compression modes
- both · openjpeg.org, 24 Sept 2026
- Free plan
- Yes · openjpeg.org, 24 Sept 2026
- Input formats
- The documented compressor accepts BMP, PGM, PGX, PNG, PNM, PPM, RAW, RAWL, TGA and TIF inputs. · github.com, 11 Oct 2026
- JPIP
- OpenJPIP implements JPEG 2000 Part 9 features including JPIP over HTTP, image indexing and region-of-interest requests. · github.com, 11 Oct 2026
- License
- The two-clause BSD license permits use and modification, including for commercial applications, with copyright retained in source or binary documentation. · openjpeg.org, 11 Oct 2026
- Lossy and lossless
- The compressor documentation describes compression-ratio and quality-in-dB layers and says the default is one lossless quality layer. · github.com, 11 Oct 2026
- Maintainer
- The project site says the Image and Signal Processing Group at Université de Louvain maintains the library. · openjpeg.org, 11 Oct 2026
- Output formats
- The documented compressor can output J2K, JP2 and J2C formats. · github.com, 11 Oct 2026
- Project status
- The repository README says the repository should be considered unmaintained and that no committer currently feels responsible for regularly reviewing tickets or pull requests. · github.com, 11 Oct 2026
- Purpose
- OpenJPEG is an open-source JPEG 2000 codec written in C. · openjpeg.org, 11 Oct 2026
- Reference software
- The project says it is officially recognized by ISO/IEC and ITU-T as JPEG 2000 Reference Software. · openjpeg.org, 11 Oct 2026
- Release
- The project site lists version 2.5.4 as its latest release. · openjpeg.org, 11 Oct 2026
- Removed components
- The repository says openjpwl, openjp3d and openmj2 were removed after release 2.4.0 and their building and working state is unknown. · github.com, 11 Oct 2026
- Supported formats
- BMP,PGM,PGX,PNG,PNM,PPM,RAW,RAWL,TGA,TIF,J2K,JP2,J2C,JPT · openjpeg.org, 24 Sept 2026
Where OpenJPEG stands on Freedom251
- Image Compression Software#38 of 85