一种基于非线性灰度变换的弱边缘检测方法  

A weak edge detection method based on nonlinear transform of gray levels

作　　者：李钦弟[1] 蔡利栋[1] 

机构地区：[1]暨南大学计算机科学系,广州510632

出　　处：《中国体视学与图像分析》2011年第3期232-236,共5页Chinese Journal of Stereology and Image Analysis

摘　　要：基于梯度的边缘检测方法在处理含有弱边缘的图像时存在问题:选取高梯度阈值会遗漏弱边缘,而选取低梯度阈值将会出现虚假边缘点。本文提出了一种基于非线性灰度变换的弱边缘检测方法。该方法首先对图像作非线性变换,沿边缘方向作平滑后再计算梯度值并进行非最大化抑制,最后参照梯度直方图选取合适的梯度阈值来标识边缘点。实验结果表明本文提出的方法能有效地检测出弱边缘。Many gradient-based edge detection algorithms have problems with images that contain weak edges： a tight threshold may fail to detect weak edges whereas a loose threshold may cause lots of false edges.A weak edge detection method based on nonlinear transform of gray level is therefore proposed.It first enhances the raw image using a nonlinear function,followed by a smoothing along the edge direction.It then calculates the gradient magnitude and makes the non-maximal suppression.Finally it labels the edge points using a threshold with Reference to the variance of the gradient histogram.Experimental results show that the proposed algorithm can detect weak edges effectively.

关 键 词：弱边缘 非线性变换 阈值 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]