图像边缘提取的定位误差产生机理分析

The Mechanism to Cause Positioning Error of Detecting Edges in Image

本文分析了使用Ｄｍａｒｒ的ＬＯＧ方法检测图像边缘时，零交叉点定位误差的产生机理，指明边缘中心邻城关于边缘中心不对称是造成零交叉点定位误差的主要原因，各类边缘的零交叉点是否定位准确与噪声存在与否并无直接的联系，关键在于噪声是否破坏了边缘相对其中心的奇函数特性．

In this paper, the mechanism to cause positioning error of zero crossing when D Marr's LOG method is used to detect the edges in an image is discussed. It is docidated that the main men to cause the positioning error is that the neighborhood of the edge center is asymmetric to the center. It is proved that the positioning accuracy of LOG method the not depend on whether noise exists or not in an edge, and the key to the positioning accuracy is whether the noise destroys the odd characteristic of the edge relative to its center.