Articulation: brightness, apparent illumination, and contrast ratios.

  title={Articulation: brightness, apparent illumination, and contrast ratios.},
  author={James A. Schirillo and Steven K. Shevell},
  volume={31 2},
Luminance edges in the environment can be due to regions that differ in reflectance or in illumination. In three experiments, we varied the spatial organization of 10 achromatic (simulated) surfaces so that some arrangements were consistent with an ecologically valid and parsimonious interpretation of 5 surfaces under two different illuminants. A constant contrast-ratio along a luminance edge in the scene allows this interpretation. The brightness of patches in this condition was compared to… CONTINUE READING