| 摘要 |
PURPOSE:To ensure a highly efficient coding of the picture information that is read out, by giving a special coding to the picture information read out by a multivalue sampling by making use of a certain correlation among the lines when the bit is changed into a plain form. CONSTITUTION:The picture information (a) containing the half tone on a read-out scanning line receives a bit planing that is expressed by the 3-bit information using the BCD code of 8 tone wedges. Thus the picture element region A having the maximum density level is obtained along with other regions B and C each. Then an unitary run-length coding is carried out by the white and black run-lengths W and B to obtain the region B of white level and the region C having the white levels other than that of the region B. The boundary part between the regions B and C is turned into the code (d) via the level changing point by the changing point relative coding method and with the region A used as a reference. Furthermore a BCD coding is carried out in turns and by a picture element for the part where the region A having the maximum level is excluded from the region C. Thus each bit information is turned to the code (e). Then the results obtained each are arranged in sequence to produce the code (f) corresponding to the picture information. |
