Camera with spatially adjustable variable density optical filter and method for controlling the same

Abstract

A camera is provided that includes an array of optical detectors and an optical filter placed adjacent the array. The optical detectors output detection signals that are used to form control signals. The filter includes spatial sections of individually adjustable optical density. The optical densities are controlled by the individual control signals. The camera outputs the combined control signals and detection signals, thus effectively providing an output with a larger dynamic range than would be provided by the detection signals of the detectors alone. An objective lens and a housing form a stand alone unit. The detectors can have different responses to different wavelengths to achieve color specific effects. Methods are further provided for controlling the filter. The detection signals are scanned to ensure that a predefined filtering condition is met. If not, control signals are iteratively generated and applied to the filter until the condition has been met. Then the detection signals are combined with the control signals to form composite signals that encode the intensity distribution of the beam. Control methods ensure greater dynamic range and accuracy. Image processing methods enhance viewability.