The light reflected from an object depends on its reflectance, the illumination, and the pose of the object within the scene. An observer is called lightness constant if the perceived reflectance (lightness) of achromatic objects stays the same despite variation in object-extrinsic factors such as illumination and pose. Here, we used a dissimilarity scaling task to measure lightness constancy a...

Conventional studies of lightness constancy have almost exclusively used flat plain stimuli and have shown that lightness matches across illuminants cannot be explained by physical matches of reflectance or luminance. The perceptual qualities that underlie lightness judgments still remain largely unknown. Real objects are often 3-D and patterned, giving additional cues for identification. We ex...

Perhaps her most important charge is that edge classification, a key part of my earlier intrinsic image theory (Gilchrist, 1979), was abandoned by anchoring theory but more recently, surreptitiously re-introduced. In fact, edge classification was never abandoned. It morphed into the idea of framework segregation. The source of the confusion lies in the following sentence: ‘‘...the belongingness...

William D. Ross Boston University Boston, MA 02215 [email protected] A neural network model of 3-D lightness perception is presented which builds upon the FACADE Theory Boundary Contour System/Feature Contour System of Grossberg and colleagues. Early ratio encoding by retinal ganglion neurons as well as psychophysical results on constancy across different backgrounds (background constancy) are us...