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

       Copyright 2003-2018, Phil Harvey (phil at owl.phy.queensu.ca)

       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.

SEE ALSO

       "JPEG Tags" in Image::ExifTool::TagNames, Image::ExifTool(3pm)