Abstract: An image processing system for effecting a predetermined transformation to data representing a multiplicity of pixels which together form an initial image so as to create data representing a multiplicity of pixels which together form a transformed image in which each pixel is formed as a weighted combination of pixels in a respective block of data in the initial image. The system includes a controller operable for each pixel in the transformed image to identify the block of data containing all pixels in the initial image that contribute to the transformed image pixel, to divide the block into a plurality of sub-blocks comprising a plurality of rows of pixel data and plurality of columns of pixel data, and to calculate for each sub-block a set of transformation coefficients depending on the predetermined transformation.