| 摘要 |
<p>Apparatus is provided for automatically peaking a luminance signal in a television receiver in response to the signal-to-noise ratio of a received signal. A correction signal is derived and this is combined with the luminance signal after delaying the luminance signal. When the signalto-noise ratio is above a threshold value the correction signal is, in fact, subtracted from the luminance signal to increase the slope of transitions in the luminance signal. This "peaking" increases the picture sharpness. Below the threshold value the luminance signal is "depeaked" by adding the correction signal to decrease the slope of the transitions. This overcomes the problem of prior "peaking" systems which insert an unacceptable amount of noise when the original signal-to-noise ratio is poor.</p> |
