Adaptive contrast enhancement method and apparatus for video signals based on time-varying nonlinear transforms

摘要

Adaptive contrast height (ACE) method and apparatus according to the present invention provides a natural kidney contrast according to the time variation characteristics of the video sequence. ; Characteristics of the video sequence that is variable in time has been described above, a non-linear transform applied to the input video sequence is thereby largely expanding the contrast of the input. Probability density function of the input video sequence varies in time (PDF) has been calculated, this time related to the video contrast predetermined parameters are extracted from the PDF. Based on the extracted video parameters, non-linear conversion function is in synchronization with the associated video image or field synchronizing signal (SYNC) thereby building a look-up table (LUT) is updated. When the LUT conversion are applied to the input video signal to provide an output signal stretched.