subsampling

But often it's most useful to make your data smaller by calculating some sort of summary statistics instead of subsampling.

The WebP authors are actually working on improving chroma subsampling, because VP8 limits WebP to 2x2.

With chroma subsampling there's tradeoff - either bleed black into color areas or bleed color outside.

Lossy image compression typically operates using a combination of planar modifications (like subsampling) and block-level modifications.

Chroma subsampling is not the only way to achieve the compression, and noahl's description equally applies to the monochromatic video.

While it does make red less dull at 2x2 chroma subsampling, it does also blur red (or orange) into (white) backgrounds.

You do see this in inner cities occasionally (like London) but again, your looking at a racist subsampling of the population.

Also, for AA you would need subsampling that is times slower than the methods that allow to draw AA lines without it.

IMO the linked study is pretty much useless, because of enforced 4:2:0 chroma subsampling.

There's also no real discussion or example of what chroma subsampling looks like.

They've even eliminated potential differences coming from colorspace conversion and chroma subsampling.

Unless they can all do 4:4:4, you have to pick a subsampling that they can all do and compare them at that so it's like-for-like.