Kobus Barnard and Graham Finlayson, "Shadow Identification using Colour Ratios," Proceedings of the IS&T/SID Eighth Color Imaging Conference: Color Science, Systems and Applications, pp. 97-101, 2000.
In this paper we present a comprehensive method for identifying probable shadow regions in an image. Doing so is relevant to computer vision, colour constancy, and image reproduction, specifically dynamic range compression. Our method begins with a segmentation of the image into regions of the same colour. Then the edges between the regions are analyzed with respect to the possibility that each is due to an illumination change as opposed to a material boundary. We then integrate the edge information to produce an estimate of the illumination field.
Keywords: shadows, color, colour, colour constancy, illumination constraints, physics, based vision
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