Compressed Digital video is used, from recording/shotting to broadcasting/streming. The codec’s jungle is a real source of science and can generate difficult workflow. But sometimes they can be destructive and there will be data loss we wouldn’t pick up. One of the method of data loss is the chromatic sub-sampling. Let’s see how it works.
With 4 :4 :4 there is no sub-sampling… it happens!
With 4:2:2 we reduced to 1/3 of the quantity of information to store. Naked eye cannot see/notice it.
With 4:2:0 we reduced to 1/2 of the quantity of information to store. Naked eye cannot see it.