| 摘要 |
PURPOSE:To peorom excellent reproduction even a photographic picture and a character picture are in the mixed state, by classifying picture information in each block of which screen is divided into binary picture region, contrast picture region and intermediate region, in response to the difference of density levels among picture elements in each block. CONSTITUTION:Picture information read from an original is alternately stored in picture memories 1 and 2 at each block. When one of the memories 1 and 2 is in storage state, the other is in readout state, and the readout content is transferred to a block memory 3. From the content of the bolck memory 3, the maximum and minimum density levels are detected out of each picture element in each block, and the level being the difference of density is compared with a preset threshold value level to discriminate the picture information in the block to any one of contrast, intermediate and binary picture. Based on the result of discrimination, a threshold value memory switchin circuit 5 selects outputs of threshold value matrix memories 6-8. |
