Abstract. In this paper, we present a new method for constructing prototypes representing a set of contours encoded by Freeman Chain Codes. Our method build new prototypes taking into account similar segments shared between contours instances. The similarity criterion was based on the Levenshtein Edit Distance definition. We also outline how to apply our method to reduce a data set without sensibly affect its representational power for classification purposes. Experimental results shows that our scheme can achieve compressions about 50% while classification error increases only by 0.75%.
MotivationFinding a set of representative prototypes from a group of contour instances is often useful for improving a classifier response time and to simplify data to be analysed by a human interpreter However, there are contexts where getting good prototypes are not sufficient because the lack of an understandable criterion about its constitution and performance. For example, with forensic purposes its important to construct a model characterising an individual handwriting style not in a black box sense but taking into account about the relations among different handwriting constitutive elements.In this work, we present a new model for computing a set of contour prototypes based on the identification of contour segments satisfying some similarity criterion which can be controlled by the user. In section 2, we explain some related techniques which have been used by our method. Section 3 describes our approach, first an algorithm to construct a prototype from two contour instances and latter the application of this algorithm to construct prototypes from a set of contour instances. Finally, some experimental results are showed in section 4.