Patent ID: 6781593
Filing Date: 2004-08-24
Classification: H04N

Abstract:
A method of quantising colours in a digital image, within a colour space, comprisingaâ€”making a set of colours occurring in the image or in a preselected part thereof; bâ€”iteratively dividing the colour space into a number of compartments in a number of steps, each compartment containing a subset of the colours of the image, each step including selecting a compartment for division on the basis of the variances of the existing compartments, and dividing said compartment into new compartments, the division being carried out until a predetermined stop criterion is met, wherein the selecting of a compartment for division and the dividing of the selected compartment into new compartments is based upon variances of the sets of colours in the compartments in a number of predetermined directions; câ€”subjecting resulting sets of colours to a predetermined test and, on the basis of the results of that test, consolidating into previous sets, and the compartments corresponding thereto; and dâ€”coding the colours in the image with a colour or code which represents the compartment in which they are situated.