OpenJPEG is an open-source library to encode and decode JPEG 2000 images.

[3] It was subsequently adopted by ImageMagick instead of JasPer in 6.8.8-2[4] and approved as new reference software for this standard in July 2015.

[5] OpenJPEG is a fork of libj2k, a JPEG-2000 codec library written by David Janssens during his master thesis at University of Louvain (UCLouvain) in 2001.

In April 2016 Grok was forked from libopenjp2 by Aaron Boxer under the more restrictive AGPL.

[6] He was aiming to close up to the performance of the much more efficient proprietary Kakadu library.