工件檢測中的圖像模板匹配

　　針對在線工件的特點(diǎn)提出了一種新的工件檢測辦法。該算法提取方向碼作為特征，分粗精兩個(gè)步驟進(jìn)行檢測，首先計(jì)算模板和子圖方向碼并計(jì)算出方向碼直方圖，粗略的計(jì)算候選匹配點(diǎn)和工件旋轉(zhuǎn)角度，然后，針對匹配候選點(diǎn)，利用子圖和模板的方向碼差值進(jìn)行精匹配。該方法在工件位置發(fā)生旋轉(zhuǎn)甚至是在遮擋和光強(qiáng)引起的光照波動等情況下，也能較好的進(jìn)行匹配。

　　Abstract:

　　In this paper， a new approach to the workpiece detection is proposed according to the characteristics of online work. The algorithm extracts orientation codes as a feature and consists of two stages: rough test and precision test. First the matching candidates are selected using histograms of orientation codes and rotation angles are computed roughly. In the second stage， matching based on differences of orientation codes between template and rotated subimage is performed only for the matching candidates. Experiments demonstrate the proposed method can also better match even in the shelter and fluctuations in light.