| 摘要 |
PURPOSE:To suppress the conspicuousness of a deteriorated area on a reproduced screen, by decreasing the difference of signal levels between a noiseless area and a noise area. CONSTITUTION:An input signal (a) is converted into a signal (f) by an LPF8 via a delay circuit 3 and then into a signal (f') by an attenuator 9. The signal (f') is added with a signal (c) given from an LPF2 with same phase to obtain a signal (g). In this case, the rise of the signal (g) is slow as compared with the signal (c). Then a signal (h) is subtracted from the signal (a) to obtain only a high band component, and the signal (a) is converted into a signal (h) with the amplitude limited by a limiter 6. The signal (h) is subtracted from the signal (a) by an adder 20 to obtain a reproduced luminance signal (i) from which the noise component is excluded at an output terminal 7. In this case, the rise of the output (i) becomes slow to suppress the conspicuousness of a deteriorated area on a reproduced screen. Here the output of the limiter 6 is attenuated to reduce the level of the noise component contained in the output (i). As a result, the luminance is reduced for the deteriorated area of the screen. |
