一种基于投影曲线的印刷电路板图像配准方法

A Method of PCB Image Registration Based on Projective Curve

利用参考法对印刷电路板(printed circuit board,PCB)进行检测时的关键步骤之一就是对PCB图像的精确定位,对此提出一种基于投影曲线的图像配准方法。该方法将采集到的彩色图像转化为灰度图像,利用减影法将待测区域与背景分离并得到不含背景信息的目标图像后,利用Radon变换提取相关投影曲线。通过曲线相似性判断及投影坐标比较得到图像偏差量并加以校正。从仿真测试结果可以看出,实验计算简单、误差微小、计算精度要求低、具有普遍实用性。

Accurate positioning is one of the key steps of using the reference method for detection of PCB （ prin- ted circuit board）. A method of image registration based on projection curve was proposed. The color image were turned into gray and subtraction was used to separate the ROI （ region of interest） and the background. Then the pro- jection curve was extracted by Radon transform after getting the target image without background. To get the image projected coordinate deviation and corrected by comparing the similarity of the curve. From the simulation results it can be seen that the method has the following advantages：simple calculation, small error, low precision require- ments, general applicability.