A method of image processing. The method comprises obtaining a set of image data, the set being associated with one or more parameters representative of one or more image capture characteristics for the set and comprising pixel intensity values representing image pixels having respective pixel locations in an image. The method comprises, for a given pixel intensity value in the set: determining an estimated noise value based on at least: the one or more parameters associated with the set, and a representative intensity value derived from one or more pixel intensity values in the set. The method comprises associating the estimated noise value with the given pixel intensity value.