Video brightness/contrast enhancement method adaptive to a scene and circuit therefor

摘要

The present invention relates to an image enhancement circuit which adaptively controls the brightness and contrast of a video input signal according to its average brightness level. The circuit calculates the average brightness level during a predetermined period with respect to a video signal to be input through an input terminal and controls the brightness and contrast of the video input signal according to brightness correction characteristics corresponding to the calculated average brightness level, in which the range of the average brightness level in the video input signal is divided into a plurality of areas, and a plurality of input-output characteristic curves are provided so that the brightness and contrast of the video input signal is differently corrected for respective areas. The present invention naturally displays even a dimly lit picture by preventing an abrupt variation in brightness, and provides pictures with enhanced brightness and contrast by adjusting only the contrast at a particular nAPL range.