[Ffmpeg-devel] [PATCH] DV image quality improvement
Sat Feb 25 22:45:10 CET 2006
I agree that PSNR is not the be-all-and-end-all of quality
I wish to reiterate however that this particular patch produces a
noticeable reduction in DCT quantization artifacts ("mosquito
netting"). It is easiest to see by doing an A/B comparison, flipping
between frames created with and without the patch.
* Christian Iversen (chrivers at iversen-net.dk) wrote:
> On Saturday 25 February 2006 21:18, Dan Maas wrote:
> > The attached (very small) patch improves image quality from ffmpeg's
> > DV encoder, increasing PSNR by about 3dB on the BBC's test footage.
> Not at all commenting on the quality of the patch in question (which is
> probably great), when are "we" (meaning "you" :-) going to stop using PSNR as
> a quality measure? There is only a quite weak correlation between percieved
> image quality and PSNR.
> There are other quality measures available that will give much better results.
> A difference of 3dB really proves very, very little about how good the result
> Could any sort of consensus about this be reached? I think there is potential
> for the ffmpeg developers to discover that certain "improvements" from the
> past in reality does little or nothing for the image quality. Of course, this
> is all conjecture until somebody tries out the other methods :-)
> (And I'm sorry, I just don't have the time at the moment. Would make for a
> very interesting project though)
> Christian Iversen
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