Locally adaptive high range image reproduction inspired by human visual system

Abstract

Dynamic range of natural scenes that we see in daily life ranges up to 120dB. Unfortunately, typical imaging devices only cover about 50dB without any special circuit technique. To overcome this dynamic range problem, many algorithms and devices have been developed and commercialized. However, commercialization in the field where image quality is emphasized is not as active as in the filed where the image information is emphasized. This is because there are still some limitations in capturing and displaying high dynamic range (HDR) image without loss of image information (color, edge and contrast, etc.) In displaying HDR image, some losses of image information during tone reproduction are inevitable, since the HDR image have to be processed with some kind of tone reproduction method to compress the dynamic range fit to the low dynamic range (LDR) display devices. Also there is a report that the tone reproduced LDR image on LDR display device is viewed better than HDR image on HDR display according to Oh [1] . For this reason, we propose a new method which can tonally reproduce HDR image into a natural LDR image as auto exposed (AE) one with minimum loss of image information.