1 | initial version |
An YUV image is composed of three channels: luminance/luma (Y/Y'), chroma blue (U), chroma red (V).
If your image is in YUV space and appears grayscale, it has no blue and red components, only luminance, zero blue and red components. Or if your image is in RGB space and grayscale, its R, G and B values are not too diverse, e.g. (R,G,B) = (120,115,123).
Conversion is done by: