Tone mapping for HDR images with dimidiate luminance and spatial distributions of bright and dark regions

Abstract

This paper proposes a novel tone mapping method in consideration of human's perception for a high dynamic range (HDR) image with dimidiated luminance and spatial distributions of bright and dark regions. In order to represent an HDR image with a low dynamic range (LDR) display, it is necessary to appropriately compress a dynamic range of HDR image by tone mapping.There are some HDR images which cannot represent the real scene precisely by applying conventional tone mapping methods. In this study, we view an HDR image with dimidiated luminance and spatial distributions of bright and dark regions as a target image for our work,we assume that human's perception dose not feel a sense of discomfort even if a magnitude relationship between luminance values of pixels near the boundary of the regions is reversed, when bright and dark regions are definitely divided according to dimidiated luminance and spatial distributions. Under the assumption, we divide HDR image into bright and dark regions and apply a tone mapping method to each region independently. In experiments, we will show that our tone mapping method produces the image represented by utilizing a dynamic range effectively. In addition, we will confirm that our tone mapping method is useful through subjective evaluation and discuss the features of the HDR images which are supposed to be suitable for the proposed method.