Difference between revisions of "YCbCr"
m (YUV moved to YCbCr: common digital video is always YCbCr; YUV is a different codec, which is uses in analog PAL, not in digital video)
Revision as of 06:17, 17 September 2006
Many modern video codecs rely on a YUV colorspace. 'YUV' is a frustrating acronym since it is so difficult to guess what the letters could possibly stand for. The colorspace was originally known as YCbCr, with the 'b' and 'r' characters written as subscripts. This is what the components represent:
- Y = luminance, or intensity
- U = Cb = blue chrominance value
- V = Cr = red chrominance value
Where is green represented? Green can be derived from the Y, U, and V values.
Note that with most RGB colorspaces, every single pixel has a different R, G, and B sample. The same is not true with YUV colorspaces. YUV operates on the empirical evidence that the human eye is more sensitive to variations in the intensity of a pixel rather than variations in color. Thus, every pixel in a YUV image has an associated Y sample, but groups of pixels share U and V samples.
For information on specific YUV formats, see the YUV formats category page.