YDbDr

 ( Color Space ) 

YDbDr, sometimes written $YD\_BD\_R$, is the colour space

used in the SECAM (adopted in France and some countries of the former Eastern Bloc) analog colour television broadcasting standard.

(2019). 9781351578646, CRC Press. . ISBN 9781351578646

Richard C. Dorf (2018). 9781420003086, CRC Press. . ISBN 9781420003086

It is very close to YUV (used on the PAL system) and its related colour spaces such as YIQ (used on the NTSC system), YPbPr and YCbCr.

(2002). 9780471379423, Wiley. . ISBN 9780471379423

(2008). 9780387326689, Springer Science & Business Media. . ISBN 9780387326689

$YD\_BD\_R$ is composed of three components: $Y$, $D\_B$ and $D\_R$. $Y$ is the luminance, $D\_B$ and $D\_R$ are the chrominance components, representing the R-Y and B-Y.

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Formulas The three component signals are created from an original $RGB$ (red, green and blue) source. The weighted values of $R$, $G$ and $B$ are added together to produce a single $Y$ signal, representing the overall brightness, or luminance, of that spot. The $D\_B$ signal is then created by subtracting the $Y$ from the blue signal of the original $RGB$, and then scaling; and $D\_R$ by subtracting the $Y$ from the red, and then scaling by a different factor.

These formulae approximate the conversion between the RGB colour space and $YD\_BD\_R$.

$\backslash begin\{align\}$

R, G, B, Y &\in \left\\ D_B, D_R &\in \left\end{align}

From RGB to YDbDr:

$\backslash begin\{align\}$

Y &= +0.299 R +0.587 G +0.114 B\\ D_B &= -0.450 R -0.883 G +1.333 B\\ D_R &= -1.333 R +1.116 G +0.217B\\ \begin{bmatrix} Y \\ D_B \\ D_R \end{bmatrix} &= \begin{bmatrix} 0.299 & 0.587 & 0.114 \\ -0.450 & -0.883 & 1.333 \\ -1.333 & 1.116 & 0.217 \end{bmatrix} \begin{bmatrix} R \\ G \\ B \end{bmatrix}\end{align}

From YDbDr to RGB:

$\backslash begin\{align\}$

R &= Y +0.000092303716148 D_B -0.525912630661865 D_R\\ G &= Y -0.129132898890509 D_B +0.267899328207599 D_R\\ B &= Y +0.664679059978955 D_B -0.000079202543533 D_R\\ \begin{bmatrix} R \\ G \\ B \end{bmatrix} &= \begin{bmatrix} 1 & 0.000092303716148 & -0.525912630661865 \\ 1 & -0.129132898890509 & 0.267899328207599 \\ 1 & 0.664679059978955 & -0.000079202543533 \end{bmatrix} \begin{bmatrix} Y \\ D_B \\ D_R \end{bmatrix}\end{align}

You may note that the $Y$ component of $YD\_BD\_R$ is the same as the $Y$ component of $Y$$U$$V$. $D\_B$ and $D\_R$ are related to the $U$ and $V$ components of the YUV colour space as follows:

$\backslash begin\{align\}$

D_B &= + 3.059 U\\ D_R &= - 2.169 V\end{align}

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See also

• YUV - related colour system

• Shi, Yun Q. and Sun, Huifang Image and Video Compression for Multimedia Engineering, CRC Press, 2000

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