The Appearance of Brightness and Lightness

In simplest terms, brightness is the appearance of luminance and lightness is the appearance of objects. The experiments in this paper measure the appearance of three visible faces of a real cube in real-life illumination. Three faces of the cube are painted white and the other three are painted different shades of gray. When the observer sees three white faces the experiment measures the appearance of illumination. When the experimenter rotates the cube to make visible a face with a different reflectance in the same illumination, then the experiment measures the appearance of objects. The results of matching experiments show that humans make the same match for luminance changes caused by illumination as those caused by reflectance. Humans can successfully recognize changes in whites due to illumination. They mistakenly interpret reflectance changes as illuminant position changes. However, in the same image they make the same matches for dark areas that were caused by illumination, re...

• Type: Conference
• Year: 2000
• Where: IMAGING
• Authors: John J. McCann
• Keywords: Cube, IMAGING 2000, IMAGING 2001, Real-life Illumination, Visible Faces