NAME

Image::JPEG::EstimateQuality - Estimate quality of JPEG images.

SYNOPSIS

use Image::JPEG::EstimateQuality;

jpeg_quality('filename.jpg');   # => 1..100 integer value
jpeg_quality(FILEHANDLE);
jpeg_quality(\$image_data);

DESCRIPTION

Image::JPEG::EstimateQuality determines quality of JPEG file. It's approximate value because the quality is not stored in the file explicitly. This module calculates quality from luminance quantization table stored in the file.

METHODS

• jpeg_quality($stuff)

  Returns quality (1-100) of JPEG file.

    scalar:     filename
    scalarref:  JPEG data itself
    file-glob:  file handle
  

SCRIPT

A script jpeg-quality distributed with the module prints the quality of a JPEG specified on the command line:

jpeg-quality image.jpg
90

LICENSE

Copyright (C) ITO Nobuaki.

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

AUTHOR

ITO Nobuaki daydream.trippers@gmail.com