Patent ID: 6384836
Filing Date: 2002-05-07
Classification: H04N

Abstract:
A method for displaying a colour image on a display device which displays the colour image using red, green, blue and white output colour components, said colour image being provided as image data comprising red, green and blue input colour components, said method comprising the steps of:mapping said image data able to be displayed by said display device into a corresponding colour point in a vector space of the red, green and blue components; displaying, by the display device, a colour image using said red, green, blue and white output colour components, wherein the output colour components are represented as additive linear combinations of the input colour components, the display device having a gamut of output colours which is able to be represented as an object having one or more concave surfaces in the vector space; moving any of said colour points of the image outside a convex hull enclosing the object to corresponding points inside or on a surface of said convex hull; maintaining any of said colour points inside the convex hull and outside said object, at substantially constant positions within said convex hull without moving; and halftoning those colors corresponding to said moved points and said maintained points of the image to produce an image that can be displayed on the display device.