摘要 |
The present invention concerns a non-linear transfer function generator, e.g., for implementating "white stretch" of a luminance signal. Specifically, first and second emitter-follower amplifiers have their inputs coupled in parallel and their outputs coupled in series via first resistor of a voltage divider. A second resistor of the voltage divider is coupled to a point of reference potential. A bias source is coupled to the second amplifier, e.g., via the second resistor of the voltage divider, so that the dynamic response of the second amplifier to an input signal is limited with respect to the first amplifier. The output signal of the first amplifier is linear and an output signal developed at the output of the first amplifier is non-linear. The linear and non-linear output signals are combined by a current steering network in response to a control signal representative of a characteristic of a processed version of the luminance signal.
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