基于相位偏折术和图像处理的表面缺陷检测

针对工业产品中类镜面透明物体表面缺陷检测的问题,研究了基于相位偏折术和图像处理结合的检测方法;采用格雷码和四步相移法解算反射条纹图的绝对相位,将绝对相位转换为梯度后可视化即可得到缺陷图;分析缺陷图中后表面干扰产生的原因,提出采用图像处理的方法消除后表面反射干扰;该方法能保留前表面缺陷,过滤后表面干扰;实验结果表明,文章所提方法能够实现对类镜面透明物体表面缺陷检测,效果较传统明场检测有较大提升.

Surface defect detection based on Phase deflection and Image processing

Aiming at the problem of surface defect detection of mirror-like transparent objects in industrial products, a detection method based on the combination of phase deflection and image processing was studied.The absolute phase of the reflected fringe pattern is solved by gray code and four-step phase shift method. The defect pattern can be visualized by converting the absolute phase to gradient.After analyzing the cause of the interference of the rear surface in the defect diagram, a method of image processing is proposed to eliminate the interference of the rear surface reflection.The method can retain the defect of the front surface and filter the interference of the rear surface.The experimental results show that the method proposed in this paper can detect the surface defects of mirror-like transparent objects, and the effect is much better than that of traditional open field detection.