Patent ID: 8107724

Claim:
A method of scaling an original image, having an original colour map and original pixel map, into a scaled image having a scaled colour map and a scaled pixel map, implemented by a computing device having a processor, the method comprising: (a) transforming the original colour map into the scaled colour map based on the original colour map and the original image independently of the scaled image, comprising: provided N min <N<N max , wherein N is a number of colours in the original colour map, and N min and N max are respective predetermined minimum and maximum numbers of colours: (a-i) selecting a sub-set M s of colours available in the original colour map, for colour enhancement, as follows: M s =N, provided N(N+1 )≦2N max ; and M s =M , where M is the smallest number M<N for which M(M−1)≧2(N max −N), provided N(N+1)>2N max; (b) scaling the original image into the scaled image; and (c) for each pixel of the scaled image: (c-i) determining a set of contributing pixels in the original image, which define a colour of the pixel; (c-ii) determining the colour of the pixel based on colours of the contributing pixels and geometric proximity of the pixel to the contributing pixels; (c-iii) establishing a correspondence between the colour of the pixel and a colour in the scaled colour map, and determining a corresponding colour map index thereof; and (c-iv) setting the determined colour map index in the scaled pixel map.