2002-07-09 21:36:37 +00:00
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artifact types:
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ringing
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2010-04-12 10:56:17 +00:00
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wave or noise like patterns around sharp edges
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bad: sinc, lanczos (with high filter length)
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acceptable: lanczos (with low filter length), cubic, spline
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ok: area, (fast)blinear, gauss, point
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2002-07-09 21:36:37 +00:00
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blur
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2010-04-12 10:56:17 +00:00
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loss of detail / high frequency
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bad: gauss with high variance
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acceptable: (fast)bilinear, area
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ok: others
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2002-07-09 21:36:37 +00:00
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2005-08-23 16:22:13 +00:00
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aliasing (only downscale)
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2010-04-12 10:56:17 +00:00
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straight lines look like staircases
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areas of high detail look worse
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regular patterns turn into a funny looking mess (moire patterns)
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bad: fast bilinear, point, gauss with low variance
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acceptable: area
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ok: others
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2002-07-09 21:36:37 +00:00
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blocky (upscale only)
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2010-04-12 10:56:17 +00:00
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looks like the image is made of rectangular blocks like a mosaic
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bad: point
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ok: others
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2002-07-09 21:36:37 +00:00
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2005-08-23 16:22:13 +00:00
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recommendations: (based upon my personal opinion many ppl might disagree ...)
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2002-07-09 21:36:37 +00:00
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---------------------------------------------------------------------
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2009-05-13 02:58:57 +00:00
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2005-08-23 16:22:13 +00:00
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the recommended scalers for upscaling:
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2002-07-09 21:36:37 +00:00
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fast_bilinear, point if speed is important
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cubic, spline, lanczos if quality is important
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2005-08-23 16:22:13 +00:00
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the recommended scalers for downscaling:
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2002-07-09 21:36:37 +00:00
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fast_bilinear, point if speed is important
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gauss, bilinear if quality is important
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cubic, spline, lanczos if a sharper picture is important
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2009-05-13 02:58:57 +00:00
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note: when encoding at a limited amount of bits (not constant quantizer)
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then a slightly blurred input might look better after decoding than a slightly
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2005-08-23 16:22:13 +00:00
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sharpened one, especially for lower bitrates
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2002-07-09 21:36:37 +00:00
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2005-08-23 16:22:13 +00:00
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sws numbers / names / artifact types
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2002-07-09 21:36:37 +00:00
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-------------------------------------------------------------------------
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r ringing
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b blurry
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a aliasing (downscale only)
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m mosaic (blocky) (upscale only)
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2010-04-12 10:56:17 +00:00
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-sws 0 fast bilinear bA
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-sws 1 bilinear b
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-sws 2 bicubic high sharpness r
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low sharpness b
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-sws 3 experimental ????
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-sws 4 nearest neighbour AM
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-sws 5 area ba
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-sws 6 luma bicubic / chroma bilinear r
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-sws 7 gauss low sharpness B
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high sharpness AM
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-sws 8 sinc R
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-sws 9 lanczos long filter R
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short filter b
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-sws 10 bicubic spline r
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2002-07-09 21:36:37 +00:00
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2009-05-13 02:58:57 +00:00
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Notes:
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2010-04-12 10:56:17 +00:00
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area upscale is identical to bilinear
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