| 摘要 |
PURPOSE:To achieve high data compression rate, by forecasting an optical density to an objective video element and coding the objective based on the forecasted error distribution. CONSTITUTION:A data for one line's share of a document in a video memory M is inputted to a register R1, and after this data is shifted at an operator S1 for one bit's share, it is inputted to a register R2. Exclusive OR operation is taken for the data in the registers R1, R2 at an exclusive OR circuit E1, and the output data is sequentially inputted to a buffer memory B via a register R3. Next, the data of the buffer memory B is inputted to a register R4 and after it is shifted at an operator S2 for one line's share, it is inputted to a register R5. Exclusive OR operation is taken for the data in the registers R4 and R5 at an exclusive OR circuit E2, the output is inputted to a coding circuit F via a count circuit C and converted into a run length code. |
