Adaptive contrast and brightness enhancement method and apparatus for color preserving

摘要

PURPOSE: A method and a device for improving contrast and brightness for color preservation are provided to selectively expand contrast according to a level of an inputted video image while restraining a color change generated in expanding the contrast. CONSTITUTION: The first brightness converting circuit(30) receives a brightness signal and a chrominance signal, reduces a level of the brightness signal in response to the first control signal, and outputs the chrominance signal and the brightness signal having the reduced level. An image converting circuit(40) receives the output signals from the first brightness converting circuit for converting the output signals into RGB(Red, Green, Blue) video signals. The second brightness converting circuit(50) receives the RGB video signals, increases a level of each RGB video signal, and outputs the RGB video signals having the increased levels.