I am forwarding to the list a mail that I send to one of the
subscribers, related to codecs comparison.
Perhaps the material will be helpful to some of you.
<p>Regards,
<p>
----
Gabriel Bouvigne
www.mp3-tech.org
personal page: http://gabriel.mp3-tech.org
<strong>attached mail follows:</strong><hr noshade>
Hello
I just looked at your vp3/mp4 comparison.
In this test you used psnr to compute differences between original and
coded samples.
You mentionned some drawbacks of psnr. I totally agree with the fact
that a few differences (lets say a small lumi difference) might give a
very bad psnr.
That is why a few years ago, I made a small tool to bypass those problems.
The tool is a difference comparator for color images. This tool allows
you to use several test criterions:
*luminance
*chrominance
*local emerging of pixels
*correllation with neighbours
*contour
This tool is limited on the size of input pictures, so you have to crop
images first.
I think that this tool might be usefull to you.
It is available on gabriel.mp3-tech.org.
I do not have time anymore to work on it (source code is available), but
if you need some information I can help you.
<p>Regards,
<p>
----
Gabriel Bouvigne
www.mp3-tech.org
personal page: http://gabriel.mp3-tech.org
<p><p>--- >8 ----
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