Abstract: There is provided a computerized method and system of controlling a quality measure in a compression quality evaluation system, the method comprising: calculating a grain value indicative of an extent of grain present in an input image, the grain value being calculated based on one or more features characterizing a base image related to the input image; and configuring the quality measure upon a criterion being met by the value, the quality measure being indicative of perceptual quality of a compressed image compressed from the input image. The calculated grain value may be dependent also on further characteristics of the input image, or in the case of a sequence of images, dependent also on the relation between the image and the preceding image.