基于HALCON的四光源光度立体法金属表面缺陷检测方法

为了提高金属表面缺陷的检测效率,提出了一种基于四光源光度立体法的检测方法。先用CCD相机采集4个不同空间角度的打孔金属试样图像。然后,利用HALCON算子,基于四光源的光度立体技术原理计算得到表面梯度图像,再将其转化为平均曲率图像。最后,把图像各点曲率值转化为灰度值,使用全局阈值分割出缺陷区域。结果表明,与经典光度立体法相比,四光源光度立体法能够准确构建图像表面梯度信息,利用图像平均曲率信息可以快速检测出金属表面缺陷。

Detection approach of metal surface defects by four-light-source photometric stereo method based on HALCON software

In order to improve the detection efficiency of metal surface defects,a detection method based on four light source photometric stereo method is proposed.Firstly,CCD camera is used to collect images of four perforated metal samples from different spatial angles.Secondly,HALCON operator is used to calculate the surface gradient image based on the principle of photometric stereo technology of four-light-source,then it is converted to the average curvature image.Finally,the curvature value of each point of the image is converted to gray value,and the global threshold is used to segment the defect area.Compared with the classical photometric stereo method,the results show that the four-light-source photometric stereo method can accurately construct the surface gradient information of the image,and the average curvature information of the image can be used to detect the defects of the metal surface quickly.