can anyone help me with this problems plz

observe for an NTSC system and calaulate the values for chromacity

Red-xr:0.67
Red-yr:0.33

Green-xg:0.21
Green-yg:0.71

Blue-xb:0.14
Blue-yb:0.08

White point-xw: 0.3101
white point-yw:0.3162

ciao,
Marco

the problem with YCrCb or RCT is that they just someway decouple chroma informations from luminance, this is good but it’s not enough cause in th end we need to store in a fixed range all this data and for instance it would be no different that using RGBE, in fact we would try to normalize Y,Cb and Cr storing an extra normalization value such an exponent.
We could use Y as normalization exponent and store Y and Cb/(Y + |Cb| + |Cr|) and Cr/(Y + |Cb| + |Cr|), moreover one would ne a pair of extra bits sto store Cb and Cr original signs.
Or we can directly use a space where chroma values are positive all the time, and there’s a nice color space that provides that which is CIE 1931 (yes, it’s old ) color space.
CIE components are called X,Y and Z. Y is a luminance-like component while X and Z are chrominance-like components, now we could store Y and x = X/(X+Y+Z) and y = Y/(X+Y+Z) (x and y are called chromacity), but we can do so much better than that, since x and y maps a light spectrum region wider than what our eyes can see.
We are lucky cause we don’t even have to scratch our heads here since the CIE commitee has arleady a solution for that and it’s called CIE Luv (to be fair there’s even another one called CIE Lab), you can find the standard transform to go from CIE XYZ to CIE Luv pretty easily (even though you want to do some extra algebra work on them to reduce the amount of calculations and thus improve accuracy).
In this space you have Y (old ‘luminance’), u and v. You can go even a step further than that, save some bits and cut the visibile spectrum even more clamping u and v between 0 and k, where k