[FFmpeg-devel] donation for snow

[Michael Niedermayer]

On Wed, Nov 19, 2008 at 03:28:47PM -0800, Jason Garrett-Glaser wrote:
> 2008/11/6 Michael Niedermayer <michaelni at gmx.at>:
> > On Thu, Nov 06, 2008 at 04:39:45PM -0800, Baptiste Coudurier wrote:
> >> Jason Garrett-Glaser wrote:
> >> >> Do you have any comparision data ? I would, too, be interested in having
> >> >> these comparisions, also knowing which jp2k encoder was used, test
> >> >> material, etc...
> >> >
> >> > I remember being linked to a paper on the topic a while back which had
> >> > the numbers I was using (though I don't remember them exactly).
> >> > However, I don't trust PSNR anyways, and if you wanted to do a real
> >> > comparison, I would say that a visual test would be the only one worth
> >> > bothering with.
> >>
> >> I understand, what puzzles me is that D-Cinema guys, who are know to be
> >> really picky about picture quality (choosing 12 bit XYZ is a thing),
> >> chose jp2k over other codecs, having done many extensive visual tests
> >> (they don't trust PSNR, Im not sure they care about it).
> >
> > heres a comparission, i hope ill find more. The one i meant was older,
> > ill try to find some more latr ...
> >
> > http://wftp3.itu.int/av-arch/jvt-site/2007_04_SanJose/JVT-W110.zip
> >
> > a brief look found in the pdf (the xls are just crashing my openoffice)
> > "
> >  Results ? SVC against JPEG2000
> >  Similar PSNR for 1088p25
> >  Visual comparisons to be performed for each resolution
> > "
> >
> > Based on this and that wavelet artifacts look more pleasing than
> > blocking artifacts i suspect but may be wrong that j2k beats h264 SVC for
> > intra coding.
> 
> I know its been a while, but I just did a small JPEG-2K vs JPG vs x264
> comparison for unrelated reasons, so I figured I'd post it.  It can be
> found here:
> 
> http://forum.doom9.org/showpost.php?p=1214866&postcount=12
> 
> The results are embarrassing.

jpeg2k is targeted on natural images, its performance with other images
may not be competetive.

Besides, the length of the command lines used makes me think the amount
of effort spend in finetuning/choosing optimal encoding parameters has
not been equally distributed.
Also h264 using all the rd, psy and pp stuff, jpeg2k should do too or
h264 should not ...

Anyway, iam not trying to defend j2k or wavelets but you are hand picking
images and parameters to make j2k look like crap, this surely does confirm
that j2k can be very significantly worse than jpeg but says little about the
average behavior. Which may or may not be better than h264, though iam pretty
sure jpeg2k will perform vastly better than its predecessor jpeg on the
average natural image.

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I have never wished to cater to the crowd; for what I know they do not
approve, and what they approve I do not know. -- Epicurus
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