1. A method of applying a convolution operator to an image, said method comprising the steps of: (a) providing a finite convolution mask having a plurality of coefficients, wherein said coefficients are arranged in a predetermined number of rows and a predetermined number of columns; (b) providing a buffer means adapted to store a portion of said image; (c) rendering to said buffer means at least a predetermined number of scan lines of said image substantially equal to the number of rows or the number of columns of said convolution mask; and (d) applying the convolution mask to said rendered plurality of scan lines to produce a scan line of an output image.