Image::ExifTool::JPEGDigest(3) Calculate JPEGDigest and JPEGQualityEstimate


This module is used by Image::ExifTool


This module contains a lookup for values of the JPEG DQT digest, allowing some image identification from JPEG data alone. It also calculates an estimated JPEG quality if requested.


Copyright 2003-2016, Phil Harvey (phil at

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.


Thanks to Jens Duttke for most of the work that went into this module, and to Franz Buchinger for the values he added.