A thrust ring for an undercarriage in a track-type machine includes an annular body having an outer circular edge and an inner circular edge defining a common center axis. The data is gathered over numerous transmit and echo receive cycles, or iterations and combined into a synthetic acquisition representing a complete echo characteristic acquisition. A white balance adjustment signal calculation circuit calculates white balance adjustment basic signals based upon the color signals output from the white balance sensor and weighting points in conformance to the photographic range, the number of sets of red color data and the subject brightness value. Incorporated into a current overload detection circuit, this allows an even spacing of the desired trip current settings about the dial of the potentiometer. A direction smoother can be applied to the directions in the edge orientation map to smooth the changing of neighboring edge directions.