JPS56149865A - Data compression method for picture processing - Google Patents

Abstract

PURPOSE:To execute the compression by quantizing an analog signal to multiple- gradation, using a displacement form code for the part where the gradation is varied by every scanning step, and using a run-length code for the part having the same gradation, in case when using a data compression system for the processing of a picture. CONSTITUTION:The optical information PS is converted to an electric signal by the photoelectric element 10, is amplified by the amplifier 11, is converted to four- valued information DL0-DL3 by the level discriminator 12, and is input to the gate circuit 13. Either two-valued or four-valued information compression is decided by a signal of the switching circuit 14, the output of the gate circuit is input to the shift registers 15-19, the outputs of the shift registers 15-17 are input to the comparator 23 and are compared, the output of the shift registers 16-19 are input to the displacement form code (TFC) encoder 24, and the information from the CPU21 is transmitted to the receiving equipment 31 through the transmission equipment 30. When the comparator 23 outputs a coincidence output, the number of the counter 22 showing the number of coincidence pieces is run-length-encoded by the CPU21, and in case of noncoincidence, the TFC code is output to the CPU21 from the encoder 24.