High-Speed Automatic Detection of Seal Impression in Bill by Template Matching

Abstract

The purpose of this paper is to find a central position of the seal impression in a bill automatically using a template matching method. The seal impression in a bill is affixed after the bill has been printed. Hence, the central position of the seal impression may be different for each bill. Since the seal impression includes much valuable information to check whether it is true or false bill, we must find the precise central position of the bill. Therefore, we use a template matching to find the central position. Background images are different for 1,000, 2,000, 5,000, and 10,000 JPY, although the seal impressions are the same. It may cause erroneous detection of the position. Then it is preferable to remove the background images. We propose a filtering algorithm to remove them. After that we adopt several algorithms to speed up the template matching. Finally, we show that the proposal method is useful to find the precise position of the seal impression.