The MPEG-2 Codec - A Practical Guide to Video and Audio Compression - page 219

Format Luma (Y') Chroma (R-Y')

Chroma (B-Y')

4:2:0

4:2:2

4:4:4

Figure 11-1 Sampling windows.

11.5 Quantization Improvements

Not much changes with quantization between MPEG-1 and MPEG-2 apart from the pre-
cision of the numbers used for coefficients. Allowing the coefficients to be specified to a
higher precision will result in more subtle shading in the encoded image. This should
reduce contouring artifacts, but it does not seem to eliminate them entirely since encoding

MPEG-1 slices MPEG-2 slices

Figure 11-2 MPEG-1 and MPEG-2 slices compared.