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Luma and colour differences

This chapter describes colour coding systems that are used to convey image data derived from additive RGB primaries. I outline nonlinear R′G′B′, explain the formation of luma, denoted Y′, as a weighted sum of these nonlinear signals, and introduce the colour difference (chroma) components [B′-Y′, R′-Y′], [C B , C R ], and [P B, P R].

The design of a video coding system is necessarily rooted in detailed knowledge of human colour perception. However, once this knowledge is embodied in a coding system, what remains is physics, mathematics, and signal processing. This chapter concerns only the latter domains.

Colour acuity

A monochrome video system ideally senses relative luminance, described on page 256. Luminance ...

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