CONTRAST ADJUSTMENT BY COMPUTING A LOCAL MEAN DENSITY

摘要

A method and apparatus are provided for performing a contrast-based dynamic range management (C-DRM) algorithm. The apparatus comprises an C-DRM processor that performs the C-DRM algorithm of the invention in order to compress an image input to the C-DRM processor down to a desired gray scale range for observation on a display. The C-DRM processor decouples adjustment of image mean values (low frequency) and image contrast values (high frequency), and manages mean and contrast separately. The use of separate mean and contrast modification functions improve on other known compression techniques by providing a more deterministic behavior and reduced complexity, allowing, for example, independent management of negative and positive contrasts. The C-DRM processor can also automatically adapt to the dynamic range of an input image so that the input image thereby applying the minimal compression needed to display the image.