PCB Positioning Based on Fractal Property of Image Edge

A novel approach of PCB image positioning is proposed. The method focuses on the rectangle mark image of PCB and analyzes the fractal property of image edge. By deleting nonordinary edge noise and compensating for the length of fractal curve, we can get the fractal dimension value from the edge curve property. An equation is deduced to represent the relation between the dimension of fractal curve and the turning angle of image. As a result, we get the angle value of PCB image exactly. Results from analyzing real image edges confirm that the fractal method is a new powerful tool for angular positioning on PCB.