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The human eye is more sensitive to intensity ("average RGB") than to color. You can drop most of the color info from a picture without significantly degrading
by sillysaurus 13y ago
The human eye is more sensitive to intensity ("average RGB") than to color. You can drop most of the color info from a picture without significantly degrading its viewing quality.
One way to do that is to transform from (r,g,b) to (intensity, chroma1, chroma2) and then downsize the chroma1 and chroma2 channels by half. When you then transform back into (r,g,b), humans can't hardly tell the difference. Whereas if you tried to do that with the intensity channel, the picture would look awful.
- lifthrasiir 13y agoChroma subsampling is not the only way to achieve the compression, and noahl's description equally applies to the monochromatic video.
- deleted 13y ago[deleted]
- atondwal 13y agoAlso note: Daala is [lossless](https://git.xiph.org/?p=daala.git;a=blob;f=doc/design.tex;h=7a2bd470fe9d4ec58544a4ed103b28fe0f6f39d0;hb=HEAD#l50 https://git.xiph.org/?p=daala.git;a=blob;f=doc/design.tex;h=...)