YDbDr, sometimes written

YD_BD_R

, is the colour space used in the

SECAM SECAM, also written SÉCAM (, ''Séquentiel de couleur à mémoire'', French for ''sequential colour memory''), is an analog color television system that was used in France, Russia and some other countries or territories of Europe and Africa. ...

(adopted in

France France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...

and some countries of the former

Eastern Bloc The Eastern Bloc, also known as the Communist Bloc (Combloc), the Socialist Bloc, the Workers Bloc, and the Soviet Bloc, was an unofficial coalition of communist states of Central and Eastern Europe, Asia, Africa, and Latin America that were a ...

) analog colour

television Television (TV) is a telecommunication medium for transmitting moving images and sound. Additionally, the term can refer to a physical television set rather than the medium of transmission. Television is a mass medium for advertising, ...

broadcasting standard. It is very close to YUV (used on the PAL system) and its related colour spaces such as

YIQ YIQ is the color space used by the analog NTSC color TV system. ''I'' stands for ''in-phase'', while ''Q'' stands for ''quadrature'', referring to the components used in quadrature amplitude modulation. Other TV systems used different color spa ...

(used on the

NTSC NTSC (from National Television System Committee) is the first American standard for analog television, published and adopted in 1941. In 1961, it was assigned the designation System M. It is also known as EIA standard 170. In 1953, a second ...

system), YPbPr and

YCbCr YCbCr, Y′CbCr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in digital video and digital photography, photography systems. Like YPbPr, YPBPR, it is based on RGB primaries; the two ...

YD_BD_R

is composed of three components:

Y

D_B

and

D_R

Y

is the

luminance Luminance is a photometric measure of the luminous intensity per unit area of light travelling in a given direction. It describes the amount of light that passes through, is emitted from, or is reflected from a particular area, and falls wit ...

D_B

and

D_R

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

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

. :

\begin
R, G, B, Y &\in \left 0, 1 \right \
D_B, D_R &\in \left -1.333, 1.333 \right end

From RGB to YDbDr: :

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

From YDbDr to RGB: :

\begin
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 R \\ G \\ B \end &=
\begin 1 & 0.000092303716148 & -0.525912630661865 \\
1 & -0.129132898890509 & 0.267899328207599 \\
1 & 0.664679059978955 & -0.000079202543533 \end
\begin Y \\ D_B \\ D_R \end\end

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: :

\begin
D_B &= + 3.059 U\\
D_R &= - 2.169 V\end

References

* Shi, Yun Q. and Sun, Huifang ''Image and Video Compression for Multimedia Engineering'', CRC Press, 2000 {{Color space Color space

Formulas

See also

References