A method is disclosed for determining an adjustment amount to be made to
an input chroma, C.sub.in, to squeeze the input chroma toward a region of
preferred chroma, C.sub.pref. This method involving first defining a
change in chroma as: .DELTA.C=C.sub.in-C.sub.pref and defining a chroma
weight as: C.sub.weight=Gaussian(C.sub.pref,C.sub.sigma); defining a
luminance weight as: L.sub.weight=Gaussian(L.sub.pref,L.sub.sigma);
defining a hue weight as: H.sub.weight=Gaussian(H.sub.pref,H.sub.sigma);.
Then, an amount of chroma adjustment is:
C.sub.Adjust=.DELTA.C*(H.sub.weight*C.sub.weight*L.sub.weight). An output
chroma is generated by applying chroma adjustment to chroma input:
C.sub.out=C.sub.in-C.sub.Adjust.