As discussed in Chapter 20, the human visual system adapts to a wide range of viewing conditions. Under normal viewing, we may discern a range of around 4 to 5 log units of illumination, i.e., the ratio between brightest and darkest areas where we can see detail may be as large as 100,000 : 1. Through adaptation processes, we may adapt to an even larger range of illumination. We call images that are matched to the capabilities of the human visual system high dynamic range.
Visual simulations routinely produce images with a high dynamic range (Ward Larson & Shakespeare, 1998). Recent developments in image-capturing techniques allow multiple exposures to be aligned and recombined into a single high dynamic ...