1. A method of determining the region of interest in images of skin impressions, the skin having ridges and valleys and the images taking the form of image data, values within a first value range being assigned to the ridges and values within a second value range of the image data being assigned to the valleys, characterized in that the values of the overall image are shifted in the direction of the first value range, in that the overall image is divided into tiles, in that mean values of the shifted values for the individual tiles are compared with a reference value and in that those tiles whose mean value deviates relative to the reference value in the direction of the first value range are considered at least on a preliminary basis as belonging to the region of interest.