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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.
The IC T C P color representation scheme is conceptually related to the LMS color space, as the color transformation from RGB to IC T C P is defined by first converting RGB to LMS with a 3×3 matrix transformation, then applying the nonlinearity function, and then converting the nonlinear signals to IC T C P using another 3×3 matrix ...
For example, applying a histogram equalization directly to the channels in an RGB image would alter the color balance of the image. Instead, the histogram equalization is applied to the Y channel of the YIQ or YUV representation of the image, which only normalizes the brightness levels of the image.
For example, when an ordinary RGB digital image is compressed via the JPEG standard, the RGB color space is first converted (by a rotation matrix) to a YCbCr color space, because the three components in that space have less correlation redundancy and because the chrominance components can then be subsampled by a factor of 2 or 4 to further ...
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.
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.
Judd was the first to employ this type of transformation, and many others were to follow. Converting this RGB space to chromaticities one finds [4] [clarification needed The following formulae do not agree with u=R/(R+G+B) and v=G/(R+G+B)] Judd's UCS, with the Planckian locus and the isotherms from 1,000K to 10,000K, perpendicular to the locus.
As the value increases above 50%, it has the effect of tinting, and full lightness produces white. At zero saturation, lightness controls the resulting shade of gray. A value of zero still produces black, and full lightness still produces white. The midpoint value results in the "middle" shade of gray, with an RGB value of (128,128,128).