> btw, i have a color conversion problem
> and as people spoke about YUV/RGB colormaps,
> i may ask for an advice here :
>
> i'm using color conversions from effectv, the formulas are :
>
> /*
>  * conversion from YUV to RGB
>  *   r = 1.164*(y-16) + 1.596*(v-128);
>  *   g = 1.164*(y-16) - 0.813*(v-128) - 0.391*(u-128);
>  *   b = 1.164*(y-16)                 + 2.018*(u-128);
>  * conversion from RGB to YUV
>  *   y =  0.257*r + 0.504*g + 0.098*b + 16
>  *   u = -0.148*r - 0.291*g + 0.439*b + 128
>  *   v =  0.439*r - 0.368*g - 0.071*b + 128
>  */
>

i use exactly the same formula for conversion from the rgb colour model from
v4l and i've noticed some differences too compared to directly capturing in
yuv.. maybe the standard is not that standard?

this page mentions another formula, along side the one above. maybe you can
try that one?

http://www.fourcc.org/fccyvrgb.htm