| 摘要 |
PURPOSE:To efficiently compress dot picture data with a small-sized hard constitution by collectively compressing and encoding a maximum input data part string where the number of noncoincident data between input picture data and preceding data is equal to or smaller than a prescribed value. CONSTITUTION:A buffer memory 1, a preceding data memory 2, an exclusive OR circuit 3, a first address control part 4, a second address control part 5, a noncoincidence counter 6, a threshold circuit 7, a maximum coincidence length detecting part 8, and an encoding part 9, etc., are provided. Input picture data held in the input data holding means 1 is successively compared with data held in the preceding data holding means 2 by the comparing means 3, and the maximum input data part string where the number of noncoincident data is equal to or smaller than the prescribed value is collectively compressed and encoded by the encoding means 9. Patterns which have the noncoincidence in the range preliminarily set by the threshold circuit 7 but resemble each other are compressed and encoded in the longest state. Thus, dot picture data is efficiently compressed. |
