An image processing module restricts granular noise present in photographic image data obtained by digitization of an image by utilizing a weighted average filtering operation. The module comprises a target pixel setting section, a difference value calculation section, a weight coefficient determining section and a filtering operating section. The target pixel setting section sets one target pixel after another from a group of pixels together constituting the photographic image data. The difference value calculating section calculates a difference value between a pixel value of the target pixel and each peripheral pixel present within a calculating area centering about the target pixel and is used for the weighted average filtering operation. The weight coefficient determining section determines a weight coefficient for use in the weighted average filtering operation, in accordance with the difference value. The filtering operating section obtains a corrected pixel value for the target pixel by effecting the weighted average filtering operation with the weight coefficient.