An Image Contrast Enhancement Scheme with Noise Aware Shadow-Up Function

摘要

This paper proposes a novel image contrast enhancement method based on a noise aware shadow-up function. Images taken by digital cameras have low contrast in dark or bright regions. This is due to a limited dynamic range which imaging sensors have. For this reason, various contrast enhancement methods have been proposed. The proposed method can enhance the contrast of images without over-enhancement and noise amplification. In the proposed method, a shadow-up function is used for preventing over-enhancement. In addition, a mapping function designed by using a noise aware histogram allows not only to enhance contrast of dark region, but also to avoid amplifying noise.