Patent ID: 6229580
Filing Date: 2001-05-08
Classification: G06F,G09G,H04N

Abstract:
An image color correction apparatus, comprising:correction object designation means for designating a hue (Hue) and a hue range (m) which make an object of correction of an input image;color approximation degree calculation means for calculating, based on the hue and the hue range designated by said correction object designation means, a color approximation degree hx representative of an approximation degree of a hue of each of noticed pixels from among input pixels of the input image to the designated hue;correction coefficient designation means for designating, where correction coefficients of color signals R, G an B of each of the input pixels are represented by (a1, a2, a3), the correction coefficients;means for correcting the color signals R, G and B to color signals R', G' and B' in accordance with(R', G', B')=(R, G, B)+hx.times.(a1, a2, a3) where .times. is a multiplication symbol; andmeans for converting from a RGB coordinate system into a HSV coordinate system in the following manner:assuming:0.ltoreq.R, G, B.ltoreq.MAX;0.ltoreq.H, S, V.ltoreq.MAX;then,V=Imax=max(R, G, B)a) when V=0,S=0, H=unknownb) when V is not equal 0,S=[(Imax-Imin).times.MAX]/Imax(Imin=min(R, G, B))H=[(G-B).times.MAX]/(Imax-Imin)(If (R=V))H=[(B-R).times.MAX]/(Imax-Imin)+MAX.times.2If (G-V))H=[(R-G).times.MAX]/(Imax-Imin)+MAX.times.2(if (B=V))wherein H is normalized by,H-H/6,wherein said color approximation degree calculation means calculates, for each of the noticed pixels from among the input pixels, where HSV values are represented by (h1, s1, v1), the color approximation degree hx in accordance withhx=((m-.vertline.Hue-h1.vertline.)/m).times.s1.times.v1.