10. A method of acquiring an electronic voucher from a short message, the method which comprises: receiving a text character sequence through a short message; recognizing features of text characters in the text character sequence in an optical manner, and determining to which one of a plurality of text character groups each text character belongs based on at least one feature of each text character, wherein text characters in each of the text character groups have at least one same or similar geometry or image feature; mapping each text character to bits or a bit group corresponding to the text character group determined to form a bit stream; and decoding the bit stream to acquire a content of the electronic voucher; wherein, the plurality of text character groups are achieved by dividing a text character set in terms of the geometry or image features of the text characters of the text character set; and a criterion of dividing the text character set in terms of the geometry or image features of the text characters of the text character set includes: axial symmetry and rotational symmetry of the text characters.
10. A method of acquiring an electronic voucher from a short message, the method which comprises: receiving a text character sequence through a short message; recognizing features of text characters in the text character sequence in an optical manner, and determining to which one of a plurality of text character groups each text character belongs based on at least one feature of each text character, wherein text characters in each of the text character groups have at least one same or similar geometry or image feature; mapping each text character to bits or a bit group corresponding to the text character group determined to form a bit stream; and decoding the bit stream to acquire a content of the electronic voucher; wherein, the plurality of text character groups are achieved by dividing a text character set in terms of the geometry or image features of the text characters of the text character set; and a criterion of dividing the text character set in terms of the geometry or image features of the text characters of the text character set includes: axial symmetry and rotational symmetry of the text characters. 12. The method according to claim 10 , wherein the text character set is divided into m text character groups in terms of the geometry or image features of the text characters of the text character set, wherein m is not less than 2.