An automatic image enhancement method adaptive to the surround luminance variation for small sized mobile transmissive LCD

摘要

The loss in contrast discrimination ability of the human visual system was estimated under a variety of ambient illumination levels first. Then it was modelled as a non-linear weighting function defined in spatial frequency domain to determine which of parts of the image, whatever their spatial frequency, will appear under a given surround luminance level. The weighting function was adopted as a filter for developing an image enhancement algorithm adaptive to surround luminance. The algorithm aims to improve the image contrast under various surround levels especially for small-sized mobile phone displays through gain control of a 2D contrast sensitivity function.