Hierarchical Eigen Template Matching for Target Detection

The template matching is the basic technique of the object detection such as the defect inspection and OCR (Optical Character Recognition). It has a problem which requires a lot of computational time for detecting the XY displacement and the rotational angle of the target object. We have proposed the eigen template method for this problem. The proposed method can efficiently calculate correlation between images. However, when an input image is complicated, the method failed to detect the target object correctly. Additionally, the computational time of the method remains large still. In this paper, we propose the edge based eigen template method with robustness for the complex image compared with the previous method. Moreover, we describe an efficient matching algorithm for the eigen template method using the narrowing down process. In the evaluation experiments, we show that the proposed method can detect the target object faster and more robust to the complex image than the previous methods.