Abstract
The color constancy could be satisfactory explained if only a standard of stable spectral reflectance permanently occurred within the human visual field [1]. The spectral variations in scene illumination would be subconsciously estimated with using the reference and utilized by the visual system to correct the spectral radiations reflected by scene objects. The white details sometimes suspected to play the role are not always present and the integral spectral reflectance of scenes varies widely in nearly homochromatic scenes (meadow, sand-dunes, sea surface) [2]. Our studies on the perceptual quality judgments of lightness scale in the series of black-and-white or color prints and slides regularly varying in their optical density or in their general or partial slope [3–5] seem to imply the role for the own face areas (upper part of cheeks, nose, and upper lip) that are permanently seen on the periphery of observer's visual field. Achieving the highest visual quality of image lightness scale has shown that all the variety of scene objects were rendered within wide photometric tolerances with exception for the face parts and the diffuse-white details that remained within strict limits. The general psychological importance of human face cannot explain the visual emphasis on the small areas not involved in communicative facial gesture. The observer's face parts are illuminated by the same sources as the whole scene and normally attract no visual attention. The color constancy may be another function of peripheral vision besides the visual world stability, pupil size control, and motion detection.
PokornyJ.ShevellS.K.SmithV.C. (1991). Colour appearance and colour constancy. In: GourasP. (Ed.), The Perception of Colour. Houndmills: Macmillan, 43–61.
FosterD. H. (2003). Does colour constancy exist?. Trends in Cognitive Sciences, 7(10), 439–443.
GavrikV. V. (1991). Principles of psychophysical and psychological correspondence in the natural scene imaging. Journal of Optical Technology, 58(4), 688–692.
GavrikV. V. (1995). Probability properties and iterative isolation of independent singlefactor functions of visual image quality from multi-factor data. Journal of Optical Technology, 62(8), 232–237.
GavrikV. V. (1998). Economical subject-selective metrics of perceptible color image quality. Proceedings of SPIE, 3409 (Electronic Imaging: Processing, Printing and Publishing in Color. Zurich), 52–63.