phpman > perldoc > 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 2003-2022, 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)