YUV

The model YUV defines a colorimetric Espace in three components. The first represents the Luminance and the two others represent the Chrominance. YUV is used in the systems of televisual diffusion STAKE and NTSC. The system SECAM uses as for him colorimetric space YDbDr, derived from YUV.

Model YUV approaches much more human perception of the colors that the standard RVB used in the data-processing imagery, but not as much as the colorimetric space HSV.

In the treatment of the video signals color, one adjusts the coefficients of the signals U and V so that the peak value with peak is equal to the maximum value of Y, is 0,7 V.

Equations

Signal YUV is created since a source RVB (red, green and blue). The values of R, V and B are added according to their relative weight to obtain signal Y. This last represents the Luminance source. The signal U is obtained by withdrawing Y of the blue signal origin; in a similar way V is obtained by withdrawing Y of the red signal. What can be obtained easily with an analogical circuit.

The following equations can be used to derive Y , U and V starting from the components R , V and B :

However, the limits authorized on U and V depend on Y .

RVB with YUV:

YUV with RVB:

or by using these matrices:

$\ begin {bmatrix} Y \ \ U \ \ V \ end {bmatrix}$

\ begin {bmatrix} 0,299 & 0,587 & 0,114 \ \ -0,147 & -0,289 & 0,436 \ \ 0,615 & -0,515 & -0,100 \ end {bmatrix} \ begin {bmatrix} R \ \ V \ \ B \ end {bmatrix}

$\ begin {bmatrix} R \ \ V \ \ B \ end {bmatrix}$

\ begin {bmatrix} 1 & -0,000 \, 04 & 1,140 \ \ 1 & -0,395 & -0,581 \ \ 1 & 2,032 & -0,000 \, 5 \ end {bmatrix} \ begin {bmatrix} Y \ \ U \ \ V \ end {bmatrix}

Let us note that these coefficients are empirical.

See too

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