Wen-Yen Wu

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A two-stage string matching method for the recognition of two-dimensional (2-D) objects is proposed in this work. The first stage is a global cyclic string matching. The second stage is a local matching with local dissimilarity measure computing. The dissimilarity measure function of the input shape and the reference shape are obtained by combining the(More)
An automated visual printed circuit board (PCB) inspection is an approach used to counter difficulties occurred in human's manual inspection that can eliminates subjective aspects and then provides fast, quantitative, and dimensional assessments. Various concentrated work on detection of defects on printed circuit boards (PCBs) have been done, but it is(More)
For the advantages of high I/O count and small size, ball grid array (BGA) package techniques have been developing very fast in recent years. In this paper, a vision-based algorithm was proposed. The BGA grayscale images captured by CCD camera, and some image processing methods were applied to segment and enhance the image of solder ball. Three kinds of(More)