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Diffstat (limited to 'DOCS/OUTDATED-tech/swscaler_methods.txt')
| -rw-r--r-- | DOCS/OUTDATED-tech/swscaler_methods.txt | 68 |
1 files changed, 0 insertions, 68 deletions
diff --git a/DOCS/OUTDATED-tech/swscaler_methods.txt b/DOCS/OUTDATED-tech/swscaler_methods.txt deleted file mode 100644 index 24d2b11835..0000000000 --- a/DOCS/OUTDATED-tech/swscaler_methods.txt +++ /dev/null @@ -1,68 +0,0 @@ - -artifact types: ---------------------------------------------------------------------- -ringing - wave or noise like patterns around sharp edges - bad: sinc, lanczos (with high filter length) - acceptable: lanczos (with low filter length), cubic, spline - ok: area, (fast)blinear, gauss, point - -blur - loss of detail / high frequency - bad: gauss with high variance - acceptable: (fast)bilinear, area - ok: others - -aliasing (only downscale) - straight lines look like staircases - areas of high detail look worse - regular patterns turn into a funny looking mess (moire patterns) - bad: fast bilinear, point, gauss with low variance - acceptable: area - ok: others - -blocky (upscale only) - looks like the image is made of rectangular blocks like a mosaic - bad: point - ok: others - -recommendations: (based upon my personal opinion many ppl might disagree ...) ---------------------------------------------------------------------- - -the recommended scalers for upscaling: -fast_bilinear, point if speed is important -cubic, spline, lanczos if quality is important - -the recommended scalers for downscaling: -fast_bilinear, point if speed is important -gauss, bilinear if quality is important -cubic, spline, lanczos if a sharper picture is important - -note: when encoding at a limited amount of bits (not constant quantizer) -then a slightly blurred input might look better after decoding than a slightly -sharpened one, especially for lower bitrates - -sws numbers / names / artifact types -------------------------------------------------------------------------- -r ringing -b blurry -a aliasing (downscale only) -m mosaic (blocky) (upscale only) - --sws 0 fast bilinear bA --sws 1 bilinear b --sws 2 bicubic high sharpness r - low sharpness b --sws 3 experimental ???? --sws 4 nearest neighbour AM --sws 5 area ba --sws 6 luma bicubic / chroma bilinear r --sws 7 gauss low sharpness B - high sharpness AM --sws 8 sinc R --sws 9 lanczos long filter R - short filter b --sws 10 bicubic spline r - -Notes: - area upscale is identical to bilinear |