Definition of RGB, YUV, and YCbCr

1 YUV and RGB Color Space Transformation
After considering the Nonlinear Characteristics of Human Visual System and cathode ray tube (CRT), the correspondence between RGB and YUV can be expressed in the following equation:
Y = 0.299r + 0.587G + 0.114b
U =-0.147r-0.289G + 0.436b
V = 0.615r-0.515g-0.100b
Or, in the form of a matrix,


2 ycrcb and RGB Color Space Transformation
The color space transformation in the number field is different from the color space transformation in the simulation field. Their components are represented by Y, Cr, and CB. The Conversion Relationship with RGB space is as follows:
Y = 0.299r + 0.578G + 0.114b
Cr = (0.500r-0.4187g-0.0813b) + 128
CB = (-0.1687r-0.3313G + 0.500b) + 128
Or, in the form of a matrix,

Note: YUV and Y, Cr, CB
For Digital Circuits: The difference between YUV and Y, Cr and CB is only 128. YUV has no negative values. The highest bits of Y, Cr and CB are symbol bits, u = Cr + 128; V = CB + 128.

 

5.3.3 yiq and RGB Color Space Transformation
The correspondence between RGB and yiq is represented by the following equation:
Y = 0.299r + 0.587G + 0.114b
I = 0.596r-0.275G-0.321b
Q = maid-0.523G + 0.311b
Or, in the form of a matrix,
YUV (also known as ycrcb) is a color encoding method used by European television systems ). YUV is mainly used to optimize the transmission of color video signals, so that it is backward compatible with vintage black and white TVs. Compared with RGB video signal transmission, RGB requires three independent video signals to be transmitted at the same time.

In YUV, "Y" indicates the brightness (luminance or Luma), that is, the gray scale value, while "u" and "V" indicate the color (chrominance or chroma ), it describes the image color and saturation, and is used to specify the color of a pixel. The "brightness" is created through the RGB input signal by overlapping specific parts of the RGB signal. "Color" defines two aspects of color-tone and saturation, which are represented by Cr and CB respectively. Among them, Cr reflects the difference between the red part of the RGB input signal and the brightness value of the RGB signal, while CB reflects the difference between the blue part of the RGB input signal and the brightness value of the RGB signal, this is the so-called color difference signal, that is, we often say that the component signal (Y, r-y, B-Y ).
In professional fields, "y cb Cr" indicates digital chromatic aberration signals rather than analog chromatic aberration signals. Chromatic Aberration signal y, R-Y, B-Y signal is generally called Y, Cr, CB; used to Y, Cr, CB is a digital (PCM) chromatic aberration signal, the simulated color difference signal is Y, PR, and Pb. Therefore, we often see y, Cr, and CB inside the DVD player, while the output color difference is Y, PR, PB or YUV; YUV is the general name of the color difference signal in the European television system pal, including numbers and analog color difference signals are called YUV, so when you see YUV, you need to think of it as Y, R-Y, B-Y signal in the PAL system, it may be digital (PCM) YUV, it may be analog YUV.