Sup-Pixel Edge Detection Technology and its Application in Non-contact Measurement of Precise Parts

Abstract

The precision of traditional methods of edge detection of precise parts with linear CCD is determined by the size of CCD cells. The precision can only reach m at high cost. A sup-pixel edge detection method of CCD based on least square method and derivative operator method is proposed to improve the measurement precision. The Image Gradient obtained using derivative operator method. Point A with the max Gradient is then regarded as the point of the edge, and then the pixels nearby edge are interpolated linearly. For example, a high-speed data acquisition system is designed using high accuracy linear CCD TCD1501D and high speed A/D converter TLC5510. FIFO memory CY7C460A is used to store the converted data. Using the sample pulse of CCD as the system control clock,a high speed data acquisition and storing system with simple circuit is designed in this paper. Experimental results show that the resolution of the system design is 0.036 pixels and the measurement precision is improved by one order of magnitude over traditional methods of edge detection. It reaches sub-pixel accuracy.