NAME

Image::ExifTool::JPEGDigest - Calculate JPEGDigest and JPEGQualityEstimate

SYNOPSIS

This module is used by Image::ExifTool

DESCRIPTION

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.

AUTHOR

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

REFERENCES

https://github.com/ImageMagick/ImageMagick/blob/master/coders/jpeg.c

ACKNOWLEDGEMENTS

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