High accuracy measurement technology of CCD and its industrial application

This paper introduces a subpixel measuring method for industry dimension measurement. The new point is high accurate edge point location which is to use spatial moments to estimate the exact location of edge within a pixel. The proposed method includes of camera calibration, image preprocessing, edge detection, subpixel location and dimension obtain. In practical, there are many factors which affect the measurement result. Noise may play key role. In order to eliminate the noise effect on measurement, meanwhile, to keep it from expanding and save the details of image edge, a nonlinear filter algorithm is proposed. Furthermore, subdivision technology based on spatial moment help to improve accuracy of edge location. Real time industrial measure results have demonstrated that high accuracy dimensional measurement technology could reach the accuracy index whose maximum measure error less than 0.01 mm. Therefore, this new method can be further developed and applied in many kinds of real time applications.