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 for the extended part-2 specifications, published as ISO/IEC 15444-2. The registered MIME types are defined in RFC 3745. For ISO/IEC 15444-1 it is image/jp2.
Comparison of JPEG 2000 with the original JPEG format | |
| Filename extension | .jp2, .j2k, .jpf, .jpm, .jpg2, .j2c, .jpc, .jpx, .mj2 |
|---|---|
| Internet media type | image/jp2, image/jpx, image/jpm, video/mj2 |
| Uniform Type Identifier (UTI) | public.jpeg-2000 |
| Magic number | 00 00 00 0C 6A 50 20 20 0D 0A 87 0A / FF 4F FF 51 |
| Developed by | Joint Photographic Experts Group |
| Type of format | Graphics file format |
| Extended from | JPEG |
| Standard | ISO/IEC 15444 |
| Open format? | Yes |
| Free format? | See ยง Legal status |
| Website | jpeg |
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 still not widely supported in web browsers (other than Safari) as of 2022, and hence is not generally used on the World Wide Web.