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.

Abstract: A method and apparatus for document imaging is disclosed. The apparatus uses a flatbed scanner with a selectively opaque/transparent liquid crystal platen. The platen is divided into controllable segments defined by an electrode pattern formed within the platen itself. These segments can each be selectively made transmissive or opaque by applying appropriate voltages to the segment electrodes. An advantage of the invention is that it can operate without a platen cover, since the area of the platen not covered by the original can be made opaque. The opaque part of the platen directs imaging light back into the system, shielding a user's eyes and helping to create a white background if the platen is imaged.