Video attenuator with output combined with signal from non-linear shunt branch to provide gamma correction and high frequency detail enhancement

摘要

A video input signal is applied to a bridged-T attenuator which includes a non-linear element in the shunt branch thereof that provides increasing attenuation as the input signal increases to thereby produce a gamma corrected video output signal at the attenuator output. A current sensor in the shunt branch generates an exponentially increasing detail signal for increases in the video input signal. The detail signal is high pass filtered and combined with the gamma corrected signal by a summing circuit for providing a video output signal having gamma correction and high frequency detail augmentation.