Abstract: A real-time signal processing circuit includes circuitry for receiving input signals generated by a scanning device, and circuitry for obtaining a synchronizing signal and a first blanking signal from the receiving circuitry. The signal-processing circuit has an input stage and a processing stage which selectively generates color output signals from the input signals, each color output signal being derived from one or a combination of the input signals. The circuit also has an output stage for including a blanking output signal in the color output signals in response to the first blanking signal and outputting the color signals and the synchronizing signal.