[FFmpeg-devel] donation for snow

Stefan de Konink stefan
Fri Nov 7 05:45:57 CET 2008

On Thu, 6 Nov 2008, Jason Garrett-Glaser wrote:

> That's odd.  My general experience with wavelets is that they give
> much worse "visual quality per PSNR" than DCT-based does.  That is,
> you can get many cases where a fully PSNR-optimal wavelet image is 3db
> PSNR better than a fully PSNR-optimal DCT image (e.g. JPEG2K vs JPEG)
> but the DCT-based one *still* looks better.

the keywords are; psycho-visual model.

Our eyes have preferences and if it is one thing they do not care about it
is noise, but they hate hard unmeaningful edges (best example; linear
interpolation). As long as noise is below the threshold of recognizing
noise as a feature, like dithering is trying to mask, it will be always
prefered over meaningless hard edge features.

But from the standpoint of Wavelets; would postprocessing with
psycho-visual aspects in mind not help to improve the actual
representation opposed to the optimal information carrier?


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