Eastman-kodak Company

Sean C Kelly

Robert Michael Guidash

Bruce Harold Pillman

Peter D Burns

Donald R Williams

David Wayne Jasinski

Noise is reduced in a digital image generated by an imaging device utilizing information which specifies noise level as a function of position for the digital image. A noise reducing algorithm is applied to the digital image while one or more parameters of the noise reducing algorithm are varied. The one or more parameters are varied as a function of field position in the digital image based on the obtained noise level as a function of field position. In this way, noise is substantially reduced and is spatially equalized in the digital image.

Reduction of position dependent noise in a digital image

A method, and digital capture apparatus for use therewith, is described for correcting a channel dependent color aberration in a digital image, where the digital image is composed of a plurality of color channels. The method includes capturing an image comprising the color channels, where one of the color channels is a blurred color channel due to a channel dependent color aberration affecting that channel. Then, one of the other color channels, other than the blurred color channel, is used as an indication of an aim sharpness, and the sharpness of the blurred color channel is adjusted, at least partially, toward the aim sharpness.

Method and apparatus for correcting a channel dependent color aberration in a digital image

A method of minimizing noise in an image produced by an electronic imager comprising: determining a correction system for a range of imager integration times and a range of imager temperatures for an electronic imager which has taken a series of dark capture images and a series of flat field capture images in a calibration mode; and applying the correction system to an image produced by the electronic imager in an image capture mode.

Fixed pattern noise removal in CMOS imagers across various operational conditions

CMOS imagers can possess higher levels of imager noise than their predecessors, CCDs. This noise can be of the form of temporal variation and fixed pattern. The fixed pattern component of this noise can be removed, which is known already in the art. The invention in this disclosure is that proper correction can be developed for all imager conditions (imager integration time and imager temperature) using a single FPN (fixed pattern noise) dark map, a single FPN PRNU (pixel response nonuniformity) map, imager integration time and imager temperature. Without this invention, a dark frame capture and a flat field capture (integrating sphere), are required before every image capture, a practical impossibility in typical picture taking. Further, the estimates of both FPN maps (dark and PRNU) in this invention are improved estimates relative to such captured directly preceding image capture since such have be formed with multiple frame averaging at calibration time, thus removing any temporal noise from these map estimates. These dark FPN and PRNU FPN maps are modified by a scaling and biasing functional with the measured values of integration time and of imager temperature. A second approach is to make the biasing and scaling functions dependant only on mean dark response taken from the imager's dark pixels, at time of capture.

Images are sharpened and corrected for position dependent blur by providing a sharpening function which is adapted to operate upon signals corresponding to a selected number of pixels, providing a plurality of values which are a function of the position dependent blur; and applying the plurality of values to the sharpening function to modify the sharpening function so that after the modified sharpening function is applied to the image, a sharpened image will be provided which has been corrected for the position dependent blur.

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Rochester, NY, United States of America

Sean C Kelly