High-speed template matching algorithm using contour information
Manabu Hashimoto, Kazuhiko Sumi, Shinjiro Kawato · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1992
We propose a new high speed template matching algorithm named edge point template matching (EPTM), which can match one gray image to another closely similar image and detect small differences between them. This method uses location, strength, and direction of contours in the template image. They are stored in a one-dimensional array. This reduced template makes the computational cost lower than previous methods which have a two- dimensional template. Generally, this kind of template reduction causes a mismatch when the image is disturbed. Contour dilation of the target image improves this situation. By applying the coarse-fine algorithm and the sequential similarity detection algorithm, our method is approximately 300 times faster than the well known cross-correlation technique. A simple hardware architecture is enough to implement the algorithm, and it is possible to execute matching a 400 X 400 template on a 512 X 512 target image within 200 msec.