YCbCr
A digital image/video representation that separates a luma-like Y' component from two color-difference components, enabling chroma subsampling.
Data casually called "YUV" in digital video is often actually Y'CbCr. Y'UV refers to an analog component-video model, while Y'CbCr is a digital representation of luma and color-difference components. The distinction matters in codecs, pixel formats, and color-conversion code.
What 4:2:0 Actually Says
4:2:0 describes chroma sampling density relative to the luma grid; it is not a generic statement that "half the color is removed." Chroma siting, matrix coefficients, signal range, and transfer characteristics are also needed for an unambiguous RGB conversion.
Mixing BT.601, BT.709, and BT.2020 matrix assumptions in a video-processing pipeline can produce visible color shifts.
Source
- https://www.itu.int/epublications/publication/itu-t-h-suppl-19-2021-04-usage-of-video-signal-type-code-points