Image::ExifTool::JPEGDigest

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 2003−2020, Phil Harvey (philharvey66 at gmail.com)

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)