摘要
为检测光滑金属工件表面缺陷,以发光LED点阵作为被检工件的背景,搭建了基于平行光照明的视觉检测系统。由于工件表面与缺陷在明暗域图像中有完全相反的灰度表现,使用三个相机从不同角度采集被检工件图像;提取三幅图像中LED点阵各发光点的中心坐标,并以之作为特征点对图像实施了结合随机抽样一致(random sample consensus,RANSAC)估计的直接线性变换(direct linear transformation,DLT);最终实现了明暗域图像间的差动式融合。实验结果表明差动式融合不但有效地消除了背景带来的干扰信息,而且明显提高了缺陷与被检工件表面的对比度。
To detect the defects on a smooth metal surface,a vision system in the condition of parallel lighting was built,and a lighted LED array was put as background of the target artifact.First of all,images were captured from different angles by three cameras,because the gray feature of the target surface and the defects between the bright-field image and the dark-field image is on the contrary.Then image processing algorithms were carried out to pick up the center coordinates of every LED point,which can be used as feature points in the DLT process.Finally differential fusion between bright-field and dark-field was implemented.Experiments show that differential fusion can either eliminate background interference information effectively or improve the contrast between the target surface and defects obviously.
出处
《电子测量技术》
2016年第2期64-68,共5页
Electronic Measurement Technology
