| 摘要 |
PURPOSE:To adjust automatically picture quality in accordance with an S/N by providing an automatic gain adjusting circuit for adjusting gains of a profile correcting signal and adjusting them according to a noise level. CONSTITUTION:An input digital luminance signal is inputted to the 1st unit time delay element 31, the 1st adder 33 and an AND circuit 42. The adder 33 adds the output signal of the 2nd unit time delay element 32 to its input signal, and the output is inputted to the 2nd adder 36 through an automatic gain control circuit 34 and a multiplier 35. The 2nd adder 36 adds the output of the multiplier 35 to that of the 1st unit time delay element 31, thereby obtaining the output signal subjected to profile correction. Here gains of the automatic gain adjusting circuit 34 are made variable by a gain adjusting signal from a decoder 41, which is made variable by the S/N. Accordingly the appropriate profile correction can be automatically executed in accordance with the value of the S/N.
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