An assessment of simultaneous dynamic range for HDR rendering

Abstract

High dynamic range (HDR) image rendering has been an active research area in the last two decades. In real-world scenarios, there is a wide range of luminance (around 14 log units) between highlights and shadows. However, according to previous reports, the simultaneous dynamic range of human vision is 3.73 log cd/m2. This property suggests that it is unnecessary to compress the full dynamic range of luminance in a real-world scene for realistic rendering. In this study, we present a sequence of psychophysical experiments to determine an appropriate simultaneous dynamic range depending on the HDR scene using an HDR rendering algorithm. The experimental results are summarized as follows: (1) for an HDR scene within the range of human vision, a rendered image with a higher simultaneous dynamic range within this range is preferable, (2) for an HDR scene beyond the range of human vision, a rendered image with the same simultaneous dynamic range as that of human vision is preferable, and (3) a rendered image with a higher simultaneous dynamic range is preferably observed under ambient light rather than in a dark room.