| 摘要 |
PROBLEM TO BE SOLVED: To prevent the removal of a dot image or low contrast image by selecting the output of a 1st selecting means in the case of a nondot or selecting the output of a smoothing filter in the case of a dot. SOLUTION: A dot area separating circuit 12 is operated at the time of both a character mode and a character/photographic mode, and image area separate signal is turned to 'H' at the time of 'dot area' or turned to 'L' at the time of not the 'dot area'. Then, the output signal of a NOT circuit 21 and the output signal of an isolate point removing circuit 13 are ANDed by an AND circuit 22, and a selector 17 selects either the output signal of an MTF correcting filter 14 or the output signal of a white data register 16 based on the output signal. of the AND circuit 22. Besides, a selector 18 selects either the output signal of the selector 17 or the output signal of a smoothing filter 15 based on the image area separate signal. When impressing the image area separate signal=L through the NOT circuit 21 to the AND circuit 22, at the time of 'non-dot area', an isolate point detecting signal is made valid, the selector 17 selects white data and as a result, the selector 18 selects the white data as well. |
