JP2

JP2 is the baseline image file format defined by the JPEG 2000 standard. It encapsulates a JPEG 2000 codestream.

Identification
JP2 files begin with bytes.

Note that some Adobe applications (most notably Adobe Photoshop) produce JPX (JPEG 2000 Part 2) images that erroneously use the above byte sequence, which makes them (superficially) indistinguishable from JP2 images.

Specifications

 * ISO/IEC 15444-1 Annex I: JP2 file format syntax
 * ITU-T Rec. T.800 (not free to download)
 * JPEG 2000 Committee Drafts → fcd15444-1.pdf
 * Updated ICC profile support, bit depth and resolution clarifications - 2013 amendment to the filespec that extends support of ICC profiles and clarifies use of resolution fields in JP2
 * Updated ICC profile support, bit depth and resolution clarifications - August 2011 draft of above amendment (freely available)
 * BIIF Profile for JPEG 2000
 * JPEG 2000 Profile for the National Digital Newspaper Program (NDNP Profile)

Software
See also JPEG 2000. Note also that the jpylyzer manual includes a detailed breakdown of the JP2 format structure.
 * Konvertor
 * Jpylyzer: JP2 validator and property extractor
 * Compute compression ratio for all JP2s in directory tree (shell script)
 * RAIS Image Server: An IIIF-compliant, 100% open source tile server for JP2 images

Sample files

 * Jp2k test corpus - annotated set of images, primarily intended to demonstrate specific preservation risks


 * Jpylyzer test files - annotated set of images, primarily intended as test dataset in support of jpylyzer development. Includes many (deliberately) corrupted files.


 * JPEG 2000 sample images - sample files for each format in the JPEG 2000 format family


 * openjpeg-data - all files required to run the openjpeg test suite, includes many badly corrupted files

Related formats

 * GeoJP2 is an extension of the JP2 format which allows one to include geospatial metadata in georeferenced JP2 images.

Links

 * JPEG 2000
 * Is JPEG-2000 a Preservation Risk?
 * JP2 entries in OPF File Format Risk Registry - describes some issues with (older versions of) the format spec and issues with specific implementations
 * Six ways to decode a lossy JP2
 * Example JP2 profiles (types of JP2s used by different institutions)
 * Online demonstrator- shows quality differences between similarly-sized images in JPEG, JP2, WebP and BPG formats
 * JP2 Format Preservation Assessment (British Library)
 * Catching and potentially reporting apparent compressed bitstream errors
 * JPEG2000 Is Slow … Or Is It?