Difference between 4:2:2 and 4:1:1 is the alignment of chroma sample position. See the figure.
The HVS(Human Visual System) has poor response to chrominance spatial detail compared to its response to luminance spatial detail. This property can be exploited to reduce bandwidth requirements by subsampling the chroma components. The most commonly used subsampling patterns are illustrated in Figure. In 4:2:2 subsampling, the chroma components are subsampled by a factor of 2 horizontally. This gives a reduction of about 33% in the overall raw data rate. In 4:1:1 subsampling, the chroma components are subsampled by a factor of 4 horizontally, giving a reduction of 50%. In 4:2:0 subsampling, the chroma components are subsampled by a factor of 2 both horizontally and vertically, giving a reduction of 50% in the overall raw data rate.
2 comments:
Could you please explain the nomenclature?
Just see the figure above the blog. You will understand the difference between the YUV 4:2:0 and YUV 4:1:1.
See the chroma sample position corresponding to the luma sample position in both the cases
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