中文摘要：

针对表面裂纹边缘轮廓的不规则特性,提出了一种分段宽度评定方法.利用计算机数字图像处理的方法,在获得表面图像后,对该图像沿纵向进行分段,分别对每段的裂纹宽度用Ferret算法进行评定.为了比较不同的分段方法的优劣,提出有用信息利用率的概念,从几种分段方法中选出一种最优的方法进行分段评定,最后得出该裂纹宽度的定量评定.经过实例验证,用此方法可以定量评定裂纹的宽度,评定的结果可以为机械结构表面检测提供有效依据,该方法也可应用于一般不规则图形几何尺寸的定量评定.

英文摘要：

In consideration of the irregular outline of surface crack, a subsection method for width evaluation was proposed. Based on digital image processing, the surface image was acquired and then was divided into several lengthways subsections, the width of each of which was respectively evaluated by Ferret algorithm. For comparative evaluation of diverse sectioning methods, a conception of useful information ratio was put forward for choosing among them an optimal method, by which the quantitative evaluation of crack width was obtained. Experimental data indicate that by using the method proposed in this paper, the width of surface crack can be quantitatively evaluated. The result can provide effective criterion for mechanism surface inspection, and moreover, this method can also be employed in quantitative evaluation for geometric dimensions of irregular graphics.