中文摘要：

为了解决金刚石砂轮表面磨粒灰度直方图阈值分割方法对区域划分存在误分割的缺陷，提出一种基于二次灰度直方图连通区域标记磨粒图像分割方法。首先，将原始金刚石磨粒图像转换为灰度图像，并对其滤波处理消除噪声。其次，设定阈值完成第一次直方图阈值分割，消除较小结构暗细节。然后，标记各个连通区域，填上不同的颜色。最后，设定阈值完成第二次直方图阈值分割，获取感兴趣目标磨粒区域。结果表明：文中方法可将感兴趣目标磨粒与背景分离，得到较好的分割效果和较高的分割效率。

英文摘要：

In this work,an approach based on two gray levels histogram connected components labeling was proposed to reduce the undesirable effects of blurred segmentation of abrasive grains on the surface of diamond grinding wheels using traditional gray histogram method.This developed approach includes following steps. Firstly,an original diamond grain image was transformed into gray image and the noise was filtered and re-moved.Secondly,the obtained grey image was segmented by setting a proper threshold value to eliminate smaller structures.Thirdly,different connected components were labeled with different colors.Finally,an-other threshold was set to complete the second histogram segmentation and extract the target grain region of interests.A case study indicated that the proposed method can precisely and efficiently segment the target grains from background.