This module converts a color float image to another coordinate system.
The default coordinate system is RGB, that is, three planes recording
the Red, Green and Blue component.
One can change the coordinate system to be YUV, following the 
CCIR 601-1 recommendation.
\index{color space!RGB}
\index{color space!YUV}
\index{color space!HSI}
\index{color space!HSV}
Be careful when converting an image from RGB to YUV : most modules 
dealing with color images are waiting RGB images and not YUV.
