FIELD: digital image shaping; automatic focusing in image clamping systems. SUBSTANCE: image area of interest and color plane of interest are chosen; area of interest is filtered off to shape filtered-off section; absolute mean value for filtered-off section and maximal absolute mean value are evaluated; absolute mean value for filtered-off section is checked for exceeding value in percent of maximal absolute mean value; optimal focal length equal to image clamping focal length is set in case absolute mean value for filtered-off section is higher than maximal absolute mean value; optimal focal length is yielded in case absolute mean value for filtered-off section is not over value in percent of maximal absolute mean value. EFFECT: enhanced speed and precision of automatic focusing for image clamping. 17 cl, 11 dwg
