Reflectance, illumination and edges
McCann, J., Parraman, C. and Rizzi, A. (2009) Reflectance, illumination and edges. In: Seventeenth Color Imaging Conference: Color Science and Engineering Systems, Technologies, and Applications, Albuquerque, New Mexico, November 9-13, 2009. Albuquerque, New Mexico: The Society for Imaging Science and Technology, pp. 2-7 Available from: http://eprints.uwe.ac.uk/7736
Full text not available from this repository
Publisher's URL: http://www.imaging.org/IST/store/epub.cfm?abstrid=...
We studied color constancy using a pair of 3-D Color Mondrian displays made of two identical sets of painted wooden shapes. There are only 6-chromatic, and 5-achromatic paints applied to nearly 100 block facets. The three-dimensional nature of these test targets adds shadows and multiple reflections not found in flat Mondrians. Observers viewed one set in uniform illumination--Low-Dynamic-Range(LDR); the other in highly directional non-uniform illumination-- High-Dynamic Range(HDR). Both 3-D Mondrians, were side-by-side, in the same room, at the same time. We used two measurement techniques to evaluate how well the appearances correlated with the object’s reflectances. First, we asked observers to compare the appearances of individual three-dimensional surfaces having identical reflectances, and recorded these changes in appearance using magnitude estimation. Second, an author painted a reproduction of the pair of Mondrians using watercolors. We measured the watercolor reflectances of the corresponding areas to quantify the change in appearances. Both measurements give us important data on how reflectance, illumination and image structure affect color constancy. A constant paint does not exhibit perfect color constancy, but rather shows significant shifts in lightness, hue and chroma in response to non-uniform illumination. Published in Seventeenth Color Imaging Conference: Color Science and Engineering Systems, Technologies, and Applications Albuquerque, New Mexico; November 2009; p. 2-7; ISBN / ISSN: 978-0-89208-288-9