[Ffmpeg-devel] upsampling of subsampled video data

Attila Kinali attila
Tue Sep 12 21:24:36 CEST 2006

On Tue, 12 Sep 2006 21:04:03 +0200
Michael Niedermayer <michaelni at gmx.at> wrote:

> > Most hardware does bicubic interpolation. Lanczos/sinc would be more
> > theoretically correct but gauss is the most artifact-immune and also
> > IMO the most theoretically correct since it's the only filter that's
> > radially decreasing in both spatial and frequency domains. But
> > probably anything more than bicubic is too expensive to do in
> > hardware.
> i think a theoretically optimal scaler would first classify each output
> sample depending on its surrounding input somehow in one of several 
> categories (based on edge direction and or variance for example) and then
> apply depending on that a (possibly precomputed) optimal linear filter

Could you elaborate this a little bit? Especialy on how you would
do classification and why you would apply different filters
(and if you feel like it, which filter would you apply in
which case?).

			Attila Kinali
egp ist vergleichbar mit einem ikea bausatz fuer flugzeugtraeger
			-- reeler in +kaosu

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