Accession Number : ADA254093


Title :   Perception of Lightness and Brightness in Complex Patterns


Descriptive Note : Annual rept. 1 May 91-30 Apr 92,


Corporate Author : EYE RESEARCH INST OF RETINA FOUNDATION BOSTON MA


Personal Author(s) : Arend, Lawrence E , Jr


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a254093.pdf


Report Date : 30 Jun 1992


Pagination or Media Count : 23


Abstract : Perception of surface color plays important part in many everyday visual tasks. Psychophysical and neurophysiological data on early visual processes suggest a number of potential sensory limitations on the accuracy of surface-color perception. A new paradigm has been used to clarify the relationships between early visual processes and perception of achromatic surface colors (shades of gray). Psychophysical measurements of perceived surface color were made using achromatic stimulus patterns that were complex enough to support unambiguous perception of surfaces and lights. Lightness (apparent reflectance), brightness (apparent luminance) and local brightness contrasts were all measured using the same stimulus patterns. According to a number of models, lightness is closely related to local brightness contrast, but the data indicated that the relationship is more complicated than previously supposed. The brightness contrast data are well described by Stiles' threshold- vs-radiance curve, which is widely thought to be a characteristic of retinal adaptation processes. Both brightness and lightness are slightly higher on dark gray backgrounds than on white backgrounds. This perceptual error appear to be independent of illumination level.


Descriptors :   *BRIGHTNESS , *VISUAL PERCEPTION , *NEUROPHYSIOLOGY , *EXPERIMENTAL PSYCHOLOGY , *PSYCHOPHYSIOLOGY , MEASUREMENT , CONTRAST , LABORATORY TESTS , MODELS , LIMITATIONS , COLORS , COLOR DISPLAYS , BACKGROUND , ILLUMINATED SIGHTS , LUMINANCE , PERCEPTION , ADAPTATION , REFLECTANCE , STIMULI , LABORATORIES , PATTERNS , IMAGES , RADIANCE , COMPARISON , ACCURACY , ILLUMINATION , SURFACES


Subject Categories : Psychology
      Anatomy and Physiology


Distribution Statement : APPROVED FOR PUBLIC RELEASE