Abstract: A method and related apparatus for finding center lines or center points of distinguishable areas in a scanned field, such as the field of view of an optical scanning device in which is positioned an integrated-circuit chip. The invention is disclosed in the form of circuitry for analyzing a serial digital data stream representative of the image of the scanned field, and for determining the positions of center lines of center points of distinguishable areas in the field falling within a selected size range. The circuitry includes separate sections for analyzing the scanned image in order to detect center lines with respect to four separate scanning directions, the outputs of these sections being synchronized with each other, although delayed from the original serial data stream, and being representative of center lines of areas falling within the selected size range.