A video signal compensator and method for compensating for differential picture brightness of an optical image due to uneven illumination is shown. The video signal compensator includes a device for generating a compensating signal substantially representing at least one parameter of a compensating waveform required to produce a video signal representing an optical image having a substantially uniform brightness. An adder operatively coupled to the compensating signal generating device and a video signal adds the compensating signal and the video signal to produce a compensating video signal used as an input to a video signal processor adjusting its gain both vertically and horizontally compensated by increasing the gain of the video signal representing that part of the optical image which is less bright than a reference and reducing the gain of the video signal representing that part of the optical image which is brighter than a reference compensating the video signal to represent an optical image having a substantially uniform brightness. The compensating signal can be generated by either an analog signal generating device or a digital signal processing device.