Abstract:  In order to improve the recognition rate，the DAG-SVM(Directed Acyclic Graph Support Vector
Machine) algorithm is applied to character recognition，and an OCＲ(Optical Character Ｒecognition) system
based on DAG-SVM，which can be divided into three components is proposed． Algorithms of image pre-
processing，image segmentation and OCＲ are researched． Image pre-processing，the first part，contains image
filtering，graying and tilt correction． And the second component is image segmentation，which contains
binaryzation and segmentation from two sides． The last part is character recognition，whose main algorithms is
researched and DAG-SVM is choosed． The system is simulated by Matlab，and the results show that the
recognition rate is 92． 86% ．

Key words:  , image pre-processing, image segmentation, image binaryzation, character recognition, support
vector machine