Patent ID: 7072509

Claim:
An image processing method of correcting the colour of a colour image, the colour image including at least two sets of image pixels, each set having a distinct colour value, and each pixel having a luminance value representing the intensity of the colour value for that pixel in the colour image, the method comprising the steps of: i) for each colour value, generating from the pixels for that colour value a low spatial frequency monochrome image including a set of smoothed image pixels; ii) for at least one colour value, selecting a sub-set of the smoothed image pixels; iii) generating one or more corresponding sub-sets of corrected smoothed image pixels by applying a colour correction function to the or each sub-set of smoothed image pixels, said function including for each colour value a contribution from corresponding smoothed image pixels in one or more of the other sets of smoothed image pixels; iv) completing one or more sets of corrected smoothed image pixels by at least one of interpolating and extrapolating from the or each of the corrected smoothed image pixels to generate similarly corrected smoothed image pixels not in the original sub-set of smoothed image pixels; and v) generating a corrected colour image by using the or each set of corrected smoothed image pixels.