| 摘要 |
PURPOSE:To prevent the inversion of the gradation of a false halftone picture at the time of executing narrowing OR processing. CONSTITUTION:A pattern 1 detection circuit 21 and a pattern 2 detection circuit 22 monitor an input picture signal, and check whether the pattern of a picture element is the pattern to cause the inversion of the gradation after being processed by a poststage narrowing processing circuit 24 and a thinning out OR circuit 25 or not. In the case of the pattern to cause the inversion of the gradation, an output switching circuit 23 outputs the pattern not to cause the inversion of the gradation as an input signal 30 instead of the input picture signal. Thus, the deterioration of picture quality due to the inversion of the gradation of the false half-tone picture is prevented. |
