Showing posts with label Conversion between RGB and YUV. Show all posts
Showing posts with label Conversion between RGB and YUV. Show all posts

Friday, May 24, 2013

Conversion between RGB and YUV

Microsoft's answer to Conversion between RGB and YUV

Converting RGB888 to YUV

The following formulas define the conversion from RGB to YUV:

Y = ( (  66 * R + 129 * G +  25 * B + 128) >> 8) +  16
U = ( ( -38 * R -  74 * G + 112 * B + 128) >> 8) + 128
V = ( ( 112 * R -  94 * G -  18 * B + 128) >> 8) + 128
These formulas produce 8-bit results using coefficients that require no more than 8 bits of (unsigned) precision. Intermediate results require up to 16 bits of precision.

Converting 8-bit YUV to RGB888

The following coefficients are used in conversion process:

C = Y - 16
D = U - 128
E = V - 128
Using the previous coefficients and noting that clip() denotes clipping a value to the range of 0 to 255, the following formulas provide the conversion from YUV to RGB:

R = clip(( 298 * C           + 409 * E + 128) >> 8)
G = clip(( 298 * C - 100 * D - 208 * E + 128) >> 8)
B = clip(( 298 * C + 516 * D           + 128) >> 8)