Trace is the important composition structure of printed circuit board,w hich connects the devices,it is also the module that taking up the highest proportion,thus,it is the major testing target of quality assurance. T...Trace is the important composition structure of printed circuit board,w hich connects the devices,it is also the module that taking up the highest proportion,thus,it is the major testing target of quality assurance. The sunken defects proposed in this paper is a w idth abnormity defect on the FPC trace,w hich w ould cause the latent open circuit defect and affect the electrical function of circuit. The problem of flexible deformation and w idth difference make the FPC trace detection harder. Therefore,this paper proposed a detection scheme combined w ith linear masks and circle distribution characteristic. Firstly,this scheme preprocessed the acquired FPC image,divided the trace into several sub-regions and obtained the line w idth values of each trace transverse section. Then the line w idth sequences w ere searched w ith the linear difference template of gray scale. Thus,the sunken defects alternative positions w ere located. Lastly,the circle distribution characteristic is defined to identify the real defect areas from the alternative regions acquired from the previous step. Thus,the detection of sunken defects on the FPC trace w as accomplished.The algorithm w as tested in the self-built image database,w hich show s the better detection performance than the other typical algorithms.展开更多
Delaunay triangulation is gradually playing an important role in the field of finite element analysis, image recognition, and medical visualization.Considering the quality and partition efficiency, a new Delaunay tria...Delaunay triangulation is gradually playing an important role in the field of finite element analysis, image recognition, and medical visualization.Considering the quality and partition efficiency, a new Delaunay triangulation method based on constrained maximum circumscribed circle is proposed. First, according to two important criteria, the empty circle features and the maximized minimum angle characteristics, we established constrained conditions. Then, we iterated the container vertices, structure triangular face linked lists, and finally got the Delaunay data. The experimental results showed that the efficiency of the improved triangulation dissection method increased by 9.47% compared with traditional triangulation algorithms in irregular triangle vertex data.展开更多
文摘Trace is the important composition structure of printed circuit board,w hich connects the devices,it is also the module that taking up the highest proportion,thus,it is the major testing target of quality assurance. The sunken defects proposed in this paper is a w idth abnormity defect on the FPC trace,w hich w ould cause the latent open circuit defect and affect the electrical function of circuit. The problem of flexible deformation and w idth difference make the FPC trace detection harder. Therefore,this paper proposed a detection scheme combined w ith linear masks and circle distribution characteristic. Firstly,this scheme preprocessed the acquired FPC image,divided the trace into several sub-regions and obtained the line w idth values of each trace transverse section. Then the line w idth sequences w ere searched w ith the linear difference template of gray scale. Thus,the sunken defects alternative positions w ere located. Lastly,the circle distribution characteristic is defined to identify the real defect areas from the alternative regions acquired from the previous step. Thus,the detection of sunken defects on the FPC trace w as accomplished.The algorithm w as tested in the self-built image database,w hich show s the better detection performance than the other typical algorithms.
基金Supported by the National Natural Science Foundation of China(51179146)the Fundamental Research Funds for the Central Universities(2010-Ia-050,2011-IV-027)
文摘Delaunay triangulation is gradually playing an important role in the field of finite element analysis, image recognition, and medical visualization.Considering the quality and partition efficiency, a new Delaunay triangulation method based on constrained maximum circumscribed circle is proposed. First, according to two important criteria, the empty circle features and the maximized minimum angle characteristics, we established constrained conditions. Then, we iterated the container vertices, structure triangular face linked lists, and finally got the Delaunay data. The experimental results showed that the efficiency of the improved triangulation dissection method increased by 9.47% compared with traditional triangulation algorithms in irregular triangle vertex data.
