Patent ID: 7508557

Claim:
An image processing system for processing a digital multi-colour image for reproduction thereof on a colour image reproduction system provided with at least five process colours defining a gamut, the image processing system comprising: a colour processing module configured to divide the gamut into a plurality of sub-gamuts such that each sub-gamut is defined by a set of only three chromatic process colours of the at least five process colours, and to select for each pixel of the digital multi-colour image a corresponding sub-gamut from the plurality of sub-gamuts; an analysis module configured to judge, for each pixel of the digital multi-colour image, whether or not to add an additional process colour of the at least five process colours to the set of only three chromatic process colours; and a generation module configured to generate image signals from the digital multi-colour image, each image signal being associated with a digital separation image of a process colour of the plurality of process colours and specifying an image density value for the associated process colour for each pixel of the digital multi-colour image, the image density value for the associated process colour for the pixel being zero if the associated process colour is not part of the set of only three chromatic process colours defining the corresponding sub-gamut.