YDbDr
YDbDr, sometimes written YDBDR, is the colour space used in the SÉCAM analog terrestrial colour television broadcasting standard, which is used in France and some countries of the former Eastern Bloc. It is very close to YUV (PAL) and its related colour spaces such as YIQ (NTSC), YPbPr and YCbCr.
YDbDr is composed of three components - 
, 
and 
. is the luminance, and are the chrominance components, representing the red and blue colour differences.
Formulas
The three component signals are created from an original RGB (red, green and blue) source. The weighted values of 
, 
and 
are added together to produce a single signal, representing the overall brightness, or luminance, of that spot. The signal is then created by subtracting the from the blue signal of the original RGB, and then scaling; and by subtracting the from the red, and then scaling by a different factor.
These formulae approximate the conversion between the RGB colour space and YDbDr.
From RGB to YDbDr:
From YDbDr to RGB:
