Image Processing Reference
In-Depth Information
Luma samples
Chroma samples
Figure 5-29
4:4:4 sampling.
Luma samples
Chroma samples
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Ignored
Sampled
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Figure 5-30
4:2:2 sampling.
Luma samples
Chroma samples
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Figure 5-31
4:1:1 sampling.
This example is different. The 4:2:0 sampling pattern takes a group of four chroma
values and averages them. Because this uses color information from two lines, some per-
sistence is required to accomplish this kind of sampling because the lines are in different
fields when an interlaced image is being sampled.
Another sampling scheme is the Y'UV arrangement, which averages the whole sam-
ple area for chroma into one large superpixel.
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