关键词: 表面组装技术, 图像匹配, 小波变换, 方差环形投影, 序贯相似

Abstract: To locate the mounted electricity components in the Printed Circuit Board（PCB），a fast image matching algorithm based on variance ring projection is proposed.Firstly，an input image is decomposed into different low levels sub-image with the walvelet-transform.Then，after getting the variance ring projection feature，the Sequential Similarity Detection Algorithm（SSDA） is exploited to represent some potential matching points.Finally，based on these points，a precisely locating phase using the correlation is introduced to get the right position.Experimental results show this method significantly reduces the computational burden and is rotation-invariant，while the precision remained fine.

Key words: Surface Mount Technology（SMT）, image matching, wavelet transform, variance ring projection, sequential similarity