Re: Chrominance and Luminance

"MyName" <[EMAIL PROTECTED]> writes:
>I found this formula to calculate Luminance e Chrominance
>L = (R + G + B) /3
>C = { R-L, G - L, B- L}
>what do negative values mean ?

I assume you mean negative chrominance values.  In the chrominance
case, you're just setting up three scales with neutral grey at the
"zero" point.  So if R-L is positive, the colour is more red than
neutral.  If R-L is negative, the colour is less red (i.e. more cyan)
than neutral grey.

>How can i split an RGB image into its Luminance and Chrominance componenet?
>A RGB image is fully described only by this two compoments?

Note that chrominance as you've described it is a 3-vector.  So you're
really converting three numbers into *four* numbers.  You can eliminate
any one of the chrominance values and not lose any information.

As for how to go about splitting the image into luminance, and
chrominance, can you write programs?  If so, you just apply the formulas
above pixel by pixel.

        Dave