PCB Inspection Using Image Processing and Wavelet Transform

摘要

In electronics mass-production manufacturing, printed circuit board (PCB) inspection is a time consuming task. Manual inspection does not guarantee that PCB defects can be detected. In this paper, a spatial filtering and wavelet-based automatic optical inspection system for detect PCB defects is presented. This approach combines wavelet image compression utility and spatial filtering. Defects are detected by subtracting the approximations of reference image wavelet transform and test image wavelet transform followed by a median filter stage. Finally, defect image is obtained by computing the inverse wavelet transform. Advantages of this approach are also described.