| 摘要 |
PURPOSE:To effectively remove a noise while preserving the outline of a character area by changing the characteristic of a filter for the case the character area is filtering-processed and the case a non-character area is filtering- processed. CONSTITUTION:An area deciding part 1 obtains the difference (maximum luminance difference) of the maximum value and the minimum value of a luminance signal among picture signals in a block, and compares this result with a threshold S determined beforehand. Then, the block whose maximum luminance difference is below the threshold S is decided to be the non-character area, and the block over the threshold S is decided to be the character area. When the area deciding part 1 decides the block to be the non-character area, it connects the contacts of switches 5, 6 so that the picture signal read out of a buffer memory 2 is processed by a first low pass filter 3 and is outputted. When it decides the block to be the character area, it connects the contacts so that the picture signal is processed by a second low pass filter 4 and is outputted. |
