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Chrominance (chroma or C for short) is the signal used in video systems to convey the color information of the picture (see YUV color model), separately from the accompanying luma signal (or Y' for short). Chrominance is usually represented as two color-difference components: U = B′ − Y′ (blue − luma) and V = R′ − Y′ (red − luma ...
Y′UV, also written YUV, is the color model found in the PAL analogue color TV standard. A color is described as a Y′ component ( luma ) and two chroma components U and V. The prime symbol (') denotes that the luma is calculated from gamma-corrected RGB input and that it is different from true luminance . [ 1 ]
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.
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. YUV: as human eyes have lower resolution in their color perception, it is more economic to put more of the bandwidth in encoding Luma. The same principle is used in YCC.
I and Q represent the chrominance information, with I indicating (roughly) orange-blue contrast, and Q indicating purple-green contrast. I and Q can be thought of as a second pair of axes on the same graph as the YUV color space, rotated 33°; therefore IQ and UV represent different coordinate systems on the same plane.
Skin damage due to sun exposure is very wavelength dependent over the UV range 295 to 325 nm, with power at the shorter wavelength causing around 30 times as much damage as the longer one. In the calculation of UV Index , a weighting curve is used which is known as the McKinlay-Diffey Erythema action spectrum. [1]
Mineral sunscreens form a barrier between the skin and the sun's rays, while chemical sunscreens bind to the top layer of skin and transform UV rays into heat that disperses, said researcher Dr ...
All luminance–chrominance formats used in the different TV and video standards such as YIQ for NTSC, YUV for PAL, YD B D R for SECAM, and YP B P R for component video use color difference signals, by which RGB color images can be encoded for broadcasting/recording and later decoded into RGB again to display them. These intermediate formats ...