Brightness preserving video contrast enhancement using S-shaped Transfer function

This paper presents an efficient perceptual model inspired efficient video contrast enhancement algorithm. We propose a S-shaped transfer function for image pixel values that effectively improves the perceived contrast while preserving brightness of the scene. The S-shaped transfer function has only one control parameter that can be adaptively chosen for different video contents, such as sports, cartoon, news, and landscape programs. Then, the input image brightness is further preserved, in order to maintain the perception of human visual system (HVS) to some special scenes, such as dark scene and seaside scene. Experiments and comparative study on VQEG Phase I test database demonstrate that the proposed S-shaped Transfer function based Brightness Preserving (STBP) contrast enhancement algorithm outperforms various histogram equalization based methods such as HE, DSIHE, RSIHE and WTHE, yet with much lower computational complexity.