YUV vs YCbCr vs RGB (Color Space)
In the confusing world of retro video standards, so many existed before things became standardised and common.
In an effort to break down the confusion, I will attempt to explain each standard and meaning in various sections.
RGB and YUV are not video standards or connectors like composite, component or VGA, they are color spaces. They define how color information can be stored/calculated. They do not refer to actual physical connectors or wires.
RGB is pure red green and blue information, so the best it can be. The color value of each channel of color on their own, to give pure RGB values.
YUV stands for Luminance (Y), blue luminance (U) and red luminance (V). It is primarily used in analog video signals like component.
YUV is a basic color model used in analog color TV broadcasting.
A great read up on RGB and YUV and the differences can be read here.
- Y is the luminance or "brightness" (greyscale) component (or the picture in black and white).
- U is the blue luminance value (i.e. how much blue should be in the picture) with a scaling factor applied.
- V is the red luminance value (i.e. how much red should be in the picture) with a scaling factor applied.
YCbCr is a scaled and offset version of the YUV color space, used in digital video applications.
YCbCr is just YUV represented differently. Whereas YUV is luminance and RB luminance, YCbCr is luminance and color difference (red minus luminance, and blue minus luminance).
- Y is the luminance or "brightness" (greyscale) component (or the picture in black and white).
- Cb (U) is the difference between blue and Y (i.e. B - Y)
- Cr (V) is the difference between red and Y (i.e. R- Y)
All DVDs, Blu-rays, cable boxes, satellite sets, and RF tuners natively transmit/store YCbCr.Â
At some point before the information is displayed on the final monitor/display, the YUV/YCbCr will get converted to RGB (with the exception of CRT displays which natively use YUV), and then the final RGB values are used to directly control the pixels on screen.
Very often incorrectly written online (almost everywhere), it is mentioned YPbPr is the analog version version of YCbCr.
It is easy to see the confusion, as YCbCr is a color space, whereas YPbPr is the name given to the physical component video cable (Y, Pb, Pr) used to transmit YCbCr color.
So more accurately, YPbPr refers to the physical component cable used to transmit YCbCr video color information.
Often YCbCr and YPbPr are used interchangeably.
A great visual reference from the link above of each channel of color information is below.
And how YUV signals combine to form the final color image.
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