Proposing a new code by considering pieces of discrete straight lines in contour shapes

Pattern substrings analysis to find high redundancy in binary shapes is carried out to improve compression levels in binary objects. Modifications of a recent set of symbols to encode arbitrary contour shapes is proposed. The concept of Pieces of Discrete Straight Lines is introduced and the probability of appearance of symbols in contours is analyzed to propose a code of nine symbols, MDF9. Also, this code is compared with the six well-known contour codes for compression without loss of information: FCCE, FCCF, VCC, 3OT, DFCCE and C_VCC. The proposed MDF9 code in this paper, gives better compression efficiency than existing codes.