Rectangular Seal Location Algorithm Based on Digital Linear Feature

The computer can reduce the interference of useless information by limiting the operation area and extracting the image of a single seal before identifying the authenticity of seal. Seal positioning is to determine the position of the seal in the image according to the geometric features of the seal. The rectangular seal region is extracted from the image to obtain a single seal image. The positioning of the seal image can greatly reduce the computation of the subsequent seal recognition and improve the accuracy and speed of the recognition operation. The difficulty of automatic locating rectangular seal lies in calculating center, side length and deflection Angle. This paper presents a method of automatic positioning of rectangular seal based on shape feature. Firstly, the color image of the seal is preprocessed to remove the useless information in the color image, and then the line segment element is used as the minimum unit to construct the line according to the rule of digital line. Quickly locate the rectangle in the image by comparing the length and direction of the line. The experimental results show that the positioning speed of the rectangular seal is improved while the accuracy is guaranteed. The position of the seal in the image can be quickly and accurately located.