Re^3: Using Perl and the GIMP to compare images

This might be of help. Didn't find it on CPAN the first time around.
In the Imager distro, Imager::Filters

Image Difference

You can create a new image that is the difference between 2 other images.

  my $diff = $img->difference(other=>$other_img);

For each pixel in $img that is different to the pixel 
in $other_img, the pixel from $other_img is given, 
otherwise the pixel is transparent black.

This can be used for debugging image differences 
("Where are they different?"), and for optimizing 
animated GIFs.

-Lee

perl digital dash (in progress)

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