| 摘要 |
PURPOSE:To improve compressibility by obtaining a run-length sequence signal, containing an array of run lengths of picture elements in time order, from an original scanning signal, by successively finding differnce values between the respective run-length values of the signal and a reference run-length value, and thus by generating an image signal on the basis of the difference values. CONSTITUTION:The run-length counter 2 of an image coding device 1 receives the original scanning signal SC of an electric binary signal obtained by scanning an original image, and then outputs a run-length sequence signal RL of every scanning line. This signal RL is supplied to a mean-value circuit 3 to obtain the white mean run-length value signal AVW and black mean run-length value AVB of one scanning line. Then, a difference device 4 finds a difference signal SB between the signal RL and the mean run-length value signals AVW and AVB, and this difference signal SB is converted by a coder 5 into binary codes, which are outputted as a differnce run-length sequence signal SRL. Thus, the compressibility of the coding of the image signal is increased. |
