关键词: 中值滤波, 曲线拟合, 亚像素, 计算机视觉, 尺寸检测

Abstract: In view of current edge detection algorithms have deficiencies, such as low positioning accuracy, slow processing speed and poor antinoise performance, etc, this paper presents a method of axial parts size detection based on image edge high accuracy positioning. By using the improved self-adapting median filtering algorithm, the improved Kirsch operator, and the fittiing method that uses quadratic function to approach the Gaussian curve in the grayscale gradient direction of image edge, this method realizes the image edge subpixel high accuracy positioning and improves the precision of dimensional measurement. Through the application of computer vision inspection of valve size, it proves that the accuracy of this algorithm presented here is precise and stable, meeting the requirements of high precision visual detection.

Key words: median filter, curve fitting, sub-pixel, computer vision, size measurement