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YCbCr is sometimes abbreviated to YCC.Typically the terms Y′CbCr, YCbCr, YPbPr and YUV are used interchangeably, leading to some confusion. The main difference is that YPbPr is used with analog images and YCbCr with digital images, leading to different scaling values for U max and V max (in YCbCr both are ) when converting to/from YUV.
HSV is a transformation of an RGB color space, and its components and colorimetry are relative to the RGB color space from which it was derived. HSL ( h ue, s aturation, l ightness/ l uminance), also known as HLS or HSI (hue, saturation, i ntensity) is quite similar to HSV , with "lightness" replacing "brightness".
RGB use in color space definitions employ primaries (and often a white point) based on the RGB color model, to map to real world color. Applying Grassmann's law of light additivity, the range of colors that can be produced are those enclosed within the triangle on the chromaticity diagram defined using the primaries as vertices .
The analogue YUV and digital YCbCr refer to a variety of linear methods to try to separate lightness from chroma signals in an RGB input using linear combination. As the input RGB values are gamma-corrected, such a separation does not truly produce lightness and two chroma signals, but a "luma" signal and two "chrominance" signals instead.
Saturation, or the lack of it, produces tones of the reference hue that converge on the zero-saturation shade of gray, which is determined by the lightness. The following examples uses the hues red, orange, and yellow at midpoint lightness with decreasing saturation. The resulting RGB value and the total intensity is shown.
The three values of the YCoCg color model are calculated as follows from the three color values of the RGB color model: [2] [] = [] [] The values of Y are in the range from 0 to 1, while Co and Cg are in the range of −0.5 to 0.5, as is typical with "YCC" color models such as YCbCr.
The scope of the terms Y′UV, YUV, YCbCr, YPbPr, etc., is sometimes ambiguous and overlapping. Y′UV is the separation used in PAL. YDbDr is the format used in SECAM and PAL-N, unusually based on non-gamma-corrected (linear) RGB, making the Y component true luminance. Y′IQ is the format used in NTSC television.
Like YC B C R, it is based on gamma corrected RGB primaries; the two are numerically equivalent but YP B P R is designed for use in analog systems while YC B C R is intended for digital video. [1] The EOTF (gamma correction) may be different from common sRGB EOTF and BT.1886 EOTF.