JPEG 2000

JPEG 2000 (JP2) is an image compression standard and coding system. It was developed from 1997 to 2000 by a Joint Photographic Experts Group committee chaired by Touradj Ebrahimi (later the JPEG president), with the intention of superseding their original JPEG standard (created in 1992), which is based on a discrete cosine transform (DCT), with a newly designed, wavelet-based method. The standardized filename extension is '.jp2' for ISO/IEC 15444-1 conforming files and .jpx or .jpf for the extended part-2 specifications, published as ISO/IEC 15444-2. The MIME types for JPEG 2000 are defined in RFC 3745. The MIME type for JPEG 2000 (ISO/IEC 15444-1) is image/jp2.

The JPEG 2000 project was motivated by Ricoh's submission in 1995 of the CREW (Compression with Reversible Embedded Wavelets) algorithm to the standardization effort of JPEG LS. Ultimately the LOCO-I algorithm was selected as the basis for JPEG LS, but many of the features of CREW ended up in the JPEG 2000 standard.

JPEG 2000 codestreams are regions of interest that offer several mechanisms to support spatial random access or region of interest access at varying degrees of granularity. It is possible to store different parts of the same picture using different quality.

JPEG 2000 is a compression standard based on a discrete wavelet transform (DWT). The standard could be adapted for motion imaging video compression with the Motion JPEG 2000 extension. JPEG 2000 technology was selected as the video coding standard for digital cinema in 2004. However, JPEG 2000 is generally not supported in web browsers for web pages as of 2024, and hence is not generally used on the World Wide Web. Nevertheless, for those with PDF support, web browsers generally support JPEG 2000 in PDFs.

Unlike the legacy .jpg format, which offers basic image compression without support for embedded metadata or access control, JPEG 2000 introduces advanced container options such as .jp2 and .jpf. Of these, the .jpf extension offers a significantly more powerful and extensible framework. It supports high-fidelity wavelet compression, layered and tiled image structures, region-of-interest encoding, and remote streaming via the JPEG 2000 Interactive Protocol (JPIP).

The .jpf extension can be used to embed machine-readable consent flags, secure face hashes, and cryptographic signatures. This format can be used along with JPIP for time-limited, revocable access to visual data.