Patent ID: 6724934
Filing Date: 2004-04-20
Classification: G09G,H04N

Abstract:
A method for controlling the brightness of an image comprising the steps of:(a) calculating brightness increases of individual primary color components of an image color signal to generate a brightness increase in a white signal of the image color signal: (b) calculating the image brightness control components by using the brightness increases of each primary color component and the white signal; and (c) adding the image brightness control components to the image color signal to generate the brightness controlled image, wherein, in the step (a), where the color signal of the image is comprised of Red, Green, Blue three-primary-color signals, b1 is a predetermined constant indicative of scale, Brt is the brightness increase of an achromatic color according to input data, Ri, Gi, and Bi are vectors of the three primary color components, and M1=(Ri&CenterDot;Ri+Gi&CenterDot;Gi+Bi&CenterDot;Bi)2,vR, vG, and vB, which are respective brightness increases of red, green, and blue components of the color signal, are determined as vR=b1*Brt*Ri/M1, vG=b1*Brt*Gi/M1, vB=b1* Brt*Bi/M1, respectively, and where c1 is a predetermined constant indicative of scale, a white signal increase W is determined as the value multiplying the constant c1 by a lowest value among the brightness increases of the primary colors.