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http://en.wikipedia.org/wiki/YCbCr

YCbCr is a family of color spaces used in video systems. Y is the luma component and Cb and Cr the blue and red chroma components. It is often confused with the YUV color space, and typically the terms YCbCr and YUV are used interchangeably, leading to confusion. In fact, when referring to signals in digital form, the term "YUV" probably really means "YCbCr" more often than not. YCbCr is sometimes abbreviated to YCC....