jp2

JP2 refers to the JPEG 2000 file format, a wrapper used to store a JPEG 2000 codestream along with color information and metadata. Defined as part of ISO/IEC 15444, the JP2 format uses a box-based structure that includes a signature box and a file-type box to organize data and attributes. Files typically carry the .jp2 extension, though related JPEG 2000 content may use other wrappers such as .j2k.

JPEG 2000 is a wavelet-based image compression standard designed as an alternative to the original JPEG. It supports both lossless and lossy compression, accommodates multiple image components and color spaces, and offers features such as progressive decoding, region-of-interest coding, and tiling. The core processing is performed by Embedded Block Coding with Optimized Truncation (EBCOT), and the entropy coding uses context-adaptive arithmetic coding. The standard also supports metadata in XML or other schemes, alpha channels, and robust color management.

JP2 and the JPEG 2000 family find use in professional contexts including digital cinema, medical imaging, and geospatial applications. In cinema, JPEG 2000 is used for distribution masters and digital cinema packages. In healthcare, JPEG 2000 is employed in certain imaging workflows and DICOM contexts. Archiving and archival-quality workflows value its high quality and lossless capabilities. Software implementations include OpenJPEG, JasPer, and Kakadu, along with various commercial tools; hardware decoders exist for specialized workflows.

Adoption outside professional settings has been limited by the format’s complexity, historical licensing considerations, and comparatively slower encoding times. Browser and consumer software support for JP2 remains limited relative to standard JPEG, contributing to its niche usage in many web and consumer applications.