计算机应用 ›› 2013, Vol. 33 ›› Issue (09): 2698-2700.DOI: 10.11772/j.issn.1001-9081.2013.09.2698

• 典型应用 • 上一篇    

基于改进Canny算子的LED晶片边缘检测

温阳东1,顾倩芸1,陈雪峰2   

  1. 1. 合肥工业大学 电气与自动化工程学院, 合肥 230009
    2. 合肥工业大学合肥工业大学 电气与自动化工程学院, 合肥 230009
  • 收稿日期:2013-03-26 修回日期:2013-04-24 出版日期:2013-09-01 发布日期:2013-10-18
  • 通讯作者: 顾倩芸
  • 作者简介:温阳东(1955-),男,安徽合肥人,教授,主要研究方向:自动控制、计算机控制、嵌入式系统、电力系统监控、继电保护;
    顾倩芸(1989-),女,江苏盐城人,硕士研究生,主要研究方向:嵌入式系统、图像处理;
    陈雪峰(1988-),女,安徽淮北人,硕士研究生,主要研究方向:电力系统监控、继电保护、调度自动化、图像处理。

LED wafer edge detection based on improved Canny operator

WEN Yangdong,GU Qianyun,CHEN Xuefeng   

  1. School of Electrical Engineering and Automation, Hefei University of Technology, Hefei Anhui 230009, China
  • Received:2013-03-26 Revised:2013-04-24 Online:2013-10-18 Published:2013-09-01
  • Contact: GU Qianyun

摘要: 为了提高全自动固晶机视觉系统中发光二极管(LED)晶片边缘特征的提取精度,提出了一种基于改进非极大值抑制(NMS)过程和双阈值求取方法的Canny边缘检测算子。传统的非极大值抑制过程,直接将中心像素点与梯度方向周围邻近的2个像素点进行比较,易导致边缘信息不准确。针对该问题,结合中心像素点本身及其梯度方向周围的3个像素点,沿着梯度方向进行双线性插值,从而实现改进的非极大值抑制过程;另外,通过对LED晶片图像灰度直方图的分析,根据其特有的三峰特性,改进了传统的最大类间方差法,采用Otsu双阈值法及新的评价函数求取高低阈值,从而避免传统Canny算法中阈值的人工调整。实验结果表明,这种方法适合LED晶片的边缘提取,并且能够获得良好的晶片边缘及两极轮廓。

关键词: Canny算子, 边缘检测, 双线性插值, Otsu双阈值, 发光二极管晶片

Abstract: An improved Canny operator was proposed to ensure the accuracy of the Light Emitting Diode (LED) wafer edge detection applied in the vision system of automatic LED die bonder. In the traditional Non-Maxima Suppression (NMS) process, inaccuracy would be caused by selecting two pixels near gradient direction as contrastive points. To solve this problem, bilinear interpolation based on the center pixel and three pixels around was made along gradient direction to implement new NMS process. In addition, the gray histogram of LED wafer was characterized by typical three peaks, and then the high threshold and the low threshold could be got by Otsu dual threshold method with new evaluation function to replace traditional artificial adjustment. The experimental results indicate that greater wafer outline and poles edges can be got by the improved Canny algorithm which is appropriate for LED wafer edge detection.

Key words: Canny operator, edge detection, bilinear interpolation, Otsu dual threshold, Light Emitting Diode (LED) wafer

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