Abstract: Filtration of an input signal implemented in the horizontal or vertical direction may disorder the gradation in oblique directions, so that oblique lines may become jagged. To deal with this situation, the following components are provided to process the input signal: a waveform correcting means (6) having a correcting characteristic that the slope for correction in the medium-luminance range is greater than that in the high-luminance range or in the low-luminance range; a processing means (7) for extracting the deviation of the input signal processed by the waveform correcting means; a picture edge strength detecting means (1); and a processing means (8) for performing operations based on the deviation of the input signal and the picture edge strength.

Abstract: Filtration of an input signal implemented in the horizontal or vertical direction may disorder the gradation in oblique directions, so that oblique lines may become jagged. To deal with this situation, the following components are provided to process the input signal: a waveform correcting means (6) having a correcting characteristic that the slope for correction in the medium-luminance range is greater than that in the high-luminance range or in the low-luminance range; a processing means (7) for extracting the deviation of the input signal processed by the waveform correcting means; a picture edge strength detecting means (1); and a processing means (8) for performing operations based on the deviation of the input signal and the picture edge strength.