Optimal contrast enhancement for tone-mapped low dynamic range images based on high dynamic range images

Tone-mapping refers to methods for rendering high dynamic range (HDR) images on low dynamic range (LDR) displays. However, strong tonal compression in tone mapping process often causes those tone-mapped LDR images to have much less local contrast compared with the original HDR images. In this paper, we propose a novel contrast enhancement algorithm to bring the local contrast of the tone mapped images closer to that of the HDR images and formulate it as an optimization problem. Simulation results suggest that the proposed method can greatly enhance the visual quality of the tone-mapped images by bringing out details in the extreme bright and dark regions.