Grok (JPEG 2000) explained

Grok
Developer:	Aaron Boxer
Latest Release Version:	14.1.0
Latest Release Date:	^[1]
Programming Language:	C++
Operating System:	macOS, Windows, POSIX
Platform:	x86-64, AArch64
Replaces:	libopenjp2
Language:	English
Genre:	Graphics software
License:	AGPL v3

Grok is a computer software library to encode and decode images in the JPEG 2000 format. It is designed for stability, high performance, and low memory usage. Grok is free and open-source software released under the GNU Affero General Public License (AGPL) version 3.

Grok was forked from OpenJPEG's libopenjp2 in April 2016 by Aaron Boxer under a copyleft license.^[2] One of his goals was to close the performance gap with the more efficient but proprietary Kakadu.^{[3] [4]} Grok fully implements the ISO/IEC 15444-1 technical standard. As of 2024, the newer, complexity-reduced High-Throughput JPEG 2000 standard (HTJ2K, ISO/IEC 15444-15, ITU-T T.814) has been implemented, with both encoding and decoding support available.

Features

• support for High-Throughput JPEG 2000 (HTJ2K) encode/decode
• fast random-access sub-image decoding using TLM markers
• full encode/decode support for ICC colour profiles
• full encode/decode support for XML, IPTC, XMP and EXIF meta-data
• full encode/decode support for monochrome, sRGB, palette, YCC, extended YCC, CIELab and CMYK colour spaces
• full encode/decode support for JPEG, PNG, BMP, TIFF, RAW, PNM and PAM image formats
• full encode/decode support for 1–16 bit precision images
• supported platforms: Linux x86-64, Linux AArch64, Windows, macOS and WebAssembly

Integration

Grok has been integrated into a number of other open source projects, including:

• Cantaloupe image server
• IIPSrv image server
• Horos medical image viewer

Further reading

• "JPEG2000 Image Compression Fundamentals, Standards and Practice", by David S. Taubman, Michael W. Marcellin.
• JPEG 2000 for Long-term Preservation: JP2 as a Preservation Format. 10.1045/may2011-vanderknijff. Johan van der Knijff. D-Lib Magazine . 2011 . 17 . 5/6 . free.
• Generating lossy access JP2s from lossless preservation masters. Johan van der Knijff. 2022.

External links

• • User guide

Notes and References

1. Web site: Releases · GrokImageCompression/grok . github.com . 2024-10-23.
2. https://openjpeg.narkive.com/xHDPBR7a/grok-jpeg-2000-discussion-group
3. https://encode.su/threads/2477-Grok-JPEG-2000-Codec
4. https://chafey.blogspot.com/2016/09/jpeg2000-decoding-performance.html