Extracting strokes from static line images based on selective searching

Extracting the stroke information is important in understanding static line images. An essential issue of stroke extraction by using a thinning process is how to handle intersections where thinning artifacts often occur. In this paper, a novel stroke extraction method based on a "selective searching'' technique is proposed. A tree structure is constructed in the vicinity of an intersection so that a correct path of a stroke can be identified by comparing the traveling cost along each candidate path of the tree. The minimum cost path corresponds to the intrinsic trajectory of the stroke at the intersection. A return-cost is calculated for each path so that better performance can be achieved. The new method has been tested extensively with static handwritten numerals extracted from the NIST data base. Experimental results show that the method is elective and reliable.