Patent ID: 6996259

Claim:
A method for counting print ridges in a captured print image frame, comprising the steps of: (A) traversing a pixel path through the captured print image frame; (B) determining a hysteresis band for the pixel path; (C) counting a number of crossings of the determined hysteresis band while traversing the pixel path; and (D) determining a number of print ridges based on the counted number of hysteresis band crossings; wherein the hysteresis band is defined by a hysteresis band first edge value and a hysteresis band second edge value, wherein step (B) comprises the steps of: (1) measuring a first ridge pixel value peak for the pixel path; (2) measuring a first valley pixel value peak for the pixel path; (3) selecting a hysteresis band center pixel value between the first ridge pixel value peak and the first valley pixel value peak; (4) calculating the hysteresis band first edge value by adding a delta value to the selected hysteresis band center pixel value; and (5) calculating the hysteresis band second edge value by subtracting the delta value from the selected hysteresis band center pixel value.