Why Does HDR Improve Images?
John J. McCann, Alessandro Rizzi · 2011
HDR photographs render a wider range of luminances in the highlights and shadows than conventional ones. Veiling glare limits HDR imaging in two distinct ways. First, camera glare limits the luminance range that can be measured accurately. Multiple exposures improve the quantization of digital records, but fail to record scene luminance accurately. Second, observers report variable appearances from the same luminance. The improvement in HDR images is due to better preservation of relative spatial information that comes from improved digital quantization. Spatial HDR image processing algorithms can be used to mimic processes developed by human vision, by chiaroscuro painters, and by early photographers that render HDR scenes in low-range outputs. Controlled Vocabulary Terms brightness; image processing equipment; photography; quantization (signal)