8. The method according to claim 6 , wherein a criterion of dividing the text character set in terms of the geometry or image features of text characters of the text character set comprises: geometry features, image features of the various regions, wherein each text character is segmented into p regions, and p is not less than 2.
6. The method according to claim 1 , wherein the text character set is divided into m text character groups in terms of a geometry or image features of the text characters of the text character set, and wherein m is not less than 2.