High Dynamic Range Imaging

摘要

The ultimate in color reproduction is a display that can produce arbitrary spectral content over a 300-800 nm range with 1 arc-minute resolution in a full spherical hologram. Although such displays will not be available until next year, we already have the means to calculate this information using physically-based rendering. We would therefore like to know: how may we represent the results of our calculation in a device-independent way, and how do we map this information onto the displays we currently own? In this paper, we give an example of how to calculate full spectral radiance at a point and convert it to a reasonably correct display color. We contrast this with the way computer graphics is usually done, and show where reproduction errors creep in. We then go on to explain reasonable short-cuts that save time and storage space without sacrificing accuracy, such as illuminant discounting and human gamut color encodings. Finally, we demonstrate a simple and efficient tone-mapping technique that matches display visibility to the original scene.