| 摘要 |
PURPOSE:To obtain a luminance signal to which luminance reproductivity and noise are controlled by making the luminance signal have gamma characteristic to conduct it. CONSTITUTION:A circuit 27 which mixes the luminance signal Y1 having the normal luminance reproductitivity with the pseudo luminance signal Y2 is provided and the mixing rate is controlled with a control signal AGC. After a mixed signal from the circuit 27 is gamma corrected in a gamma correction circuit 20, it is supplied to an arithmetic circuit 18. The control signal AGC varies according to the quantity of light made incident on a photographing part 1. The mixing circuit 27 where the mixing rate is controlled by the AGC signal mixes the signal Y1 for decrease much when the projected light quantity is much and it mixes the signal Y2 when the incident light quantity is a little. Therefore, the gamma value of a correction circuit 12 is altered far from the normal gamma value in order to alter the gamma value of the gamma correction circuit 16 to a larger value.
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