DEVICE-DIRECTED RENDERING

Rendering systems can produce images that include the entire range of visible colors. Imaging hardware, however, can reproduce only a subset of these colors: the device gamut. An image can only be correctly dis played if all of its colors lie inside of the gamut of the target devi ce. Current solutions to this problem are either to correct the scene colors by hand, or to apply gamut mapping techniques to the final imag e. We propose a methodology called device-directed rendering that perf orms scene color adjustments automatically. Device-directed rendering applies classic minimization techniques to a symbolic representation o f the image that describes the relationship of the scene lights and su rfaces to the pixel colors. This representation can then be evaluated to produce an image that is guaranteed to be in gamut. Although our pr imary application has been correcting out-of-gamut colors, this method ology can be generally applied to the problem of adjusting a scene des cription to accommodate constraints on the output image pixel values.