| 摘要 |
PURPOSE:To reproduce a high-quality picture being eliminated noise, by setting an optimum threshold level flexibly in accordance with picture element information of a specific picture element region and by making the level high when the state of an original picture is defective and the noise or the like is mixed. CONSTITUTION:Picture signal BS obtained by reading the original picture in the picture element unit is quantized into multilevels by A/D converter 2, and density levels of respective picture elements in a specific region of nXn constitution are stored temporarily collectively in multilevel density information storing circuit 2. The maximum value and the minimum value of respective picture element information read out from circuit 2 are detected by maximum value detecting circuit 3 and minimum value detecting circuit 4, and an optimum threshold level is calculated in threshold level setting circuit 5 in accordance with the output state of circuits 3 and 4. Noise elimination instructing signal NDS instructed by the operator is applied to circuit 5 and comparison decision operating circuit 6, and the optimum level and respective output information from circuit 2 and compared and decided by circuit 6, and noise components of the specific region designated by signal NDS are eliminated to make picture elements into binary code. |
