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Old 21st April 2012, 17:57   #12  |  Link
poisondeathray
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Join Date: Sep 2007
Posts: 5,346
Quote:
Originally Posted by sneaker_ger View Post
I don't know where that error comes from. If you upscale using PointResize by factor 2 and downscale by factor 2 again, you get the same result. Either chromaresample="point" does not do what I think it does, or it has something to do with the MPEG-2-chroma-placement. Will try to make a test to reproduce the issue myself, but I stand by my original statement that this is algorithm dependent and it is possible to do it without additional blurriness, but not without color skewing (putting some edge cases aside).
There was some discusion here about whether or not "PointResize" in avisynth was true nearest neighbor
http://forum.doom9.org/showthread.php?p=1569907

On a practical level, this loss occurs, even in other programs that use "nearest neighbor" - so how do it without bluriness or other detrimental effets like aliased edges in any program???

You can use the YV12 mpeg2 clip provided above in the mediafire link as a test example

Last edited by poisondeathray; 21st April 2012 at 18:00.
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