Method for electronic image dynamic range and contrast modification

DETAILED DESCRIPTION Image luminance first is separated into high and low frequency components.
The low frequency component is processed through mathematical operators, processing elements, whose variable values can be selected manually by an observer of the modified and unmodified images, or automatically by a computer that contains an edit list or other criteria for adjustments.
The high frequency component may then be separated into positive and negative going excursion components, or processed as a single signal.
The high frequency component is then modified with proportionalities that are related to the instantaneous changes to the low frequency component with variable values being determined by either an observer or a computer as above.
Then the high frequency component is processed through mathematical operators whose variables are also to be selected as above.
Then high and low frequency components are then recombined.
If the image to be modified is in color, then the color image portions red, green, blue, or chrominance can be modified directly proportional to the instantaneous ratio of magnitude changes to the luminance image.
The primary object of the present invention is to provide dynamic range and contrast modifications to video images.
It is a further object of the present invention to provide a stand alone system wherein an operator interactively adjusts dynamic range and contrast.
Another object of the present invention is to provide a system wherein dynamic range and contrast can be accomplished under computer control.
Another object of the present invention is to provide a system wherein the low frequency portion of the image can be adjusted automatically under the control of automatic gain control, AGC, circuitry.
These and other objects and advantages of the present invention will become more readily apparent to those ordinarily skilled in the art when taken in conjunction with the following description and accompanying drawings which form a part of this application