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Color Perception

  • Constancy, Transparency, Scission [ demo ]

Zaidi, Q. and Khang, B. Neural information and perceptual inferences in color constancy. (Invited).

Robilotto, R., Khang, B. and Zaidi, Q. Sensory and physical determinants of perceived achromatic transparency. Journal of Vision (Submitted).

Khang, B. and Zaidi, Q. Accuracy of color scission for spectral transparencies. Journal of Vision (Submitted).

Lee, B., Joost, U. and Zaidi, Q. Commentary on "Lichtenberg, G.C.( 1793) Letter to Johann Wolfgang von Goethe on "Farbige Schatten.&" Color Research and Application, (In press).

Khang, B. and Zaidi, Q. Cues and strategies for color constancy: perceptual scission, image junctions, transformational color matching. Vision Research, 42, 211-226, 2002. [pdf]

Zaidi, Q. Color constancy in a rough world. Color Research and Application, 26, S192-S200, 2001. [pdf]

Zaidi, Q. Identification of illuminant and object colors: heuristics based algorithms. J. Opt. Soc. Am., A15, 1767-1776, 1998. [pdf]

Zaidi, Q., Spehar, B. and DeBonet, J.S. Color constancy in variegated scenes: the role of low-level mechanisms in discounting illumination changes. J. Opt. Soc. Am., A14, 2608-2621, 1997. [pdf]


  • Cortical Color Representation

Zaidi, Q. Color representation by spiking cortical neurons.

Zaidi, Q. Is there a perceptual color space? Review of "Geometric representations of perceptual phenomena", R.D. Luce, M. D'Zmura, D. Hoffman, G.J. Iverson and A.K. Romney (eds.). Color Research and Application, 26, 325-328, 2001. [pdf]

Zaidi, Q. and Shapiro, A. Adaptive orthogonalization of opponent-color signals. Biological Cybernetics, 69, 415-428, 1993.

Zaidi, Q. and Halevy, D. Visual mechanisms that signal the direction of color changes. Vision Research, 33, 1037-1051, 1993.

Sachtler, W. and Zaidi, Q. Chromatic and luminance signals in visual memory. J. Opt. Soc. Am., A9, 877-894, 1992.

Zaidi, Q. and Halevy, D. Chromatic mechanisms beyond linear opponency. In From Pigments to Perception: Advances in Understanding Visual Processes, A. Valberg and B. Lee (Eds.), Plenum Press, London, 337-348, 1991.



  • Color and Brightness Induction  
Zaidi, Q. Color and brightness induction: From Mach bands to 3-D configurations. In Color Vision: From Genes to Perception, Gegenfurtner, K. and Sharpe, L. (eds.), Cambridge University Press, New York, 1999.

Spehar, B. and Zaidi, Q. Surround effects on the shape of the temporal contrast sensitivity function. J. Opt. Soc. Am., A14, 2517-2525, 1997. [pdf]

Zaidi, Q., Spehar, B. and Shy, M. Induced effects of backgrounds and foregrounds in three-dimensional configurations: the role of T junctions. Perception, 26, 395-408, 1997.

Spehar, B. and Zaidi, Q. New configurational effects on perceived contrast and brightness: Second-order White's effects. Perception, 26, 409-418, 1997.

DeBonet, J.S. and Zaidi, Q. Comparison between spatial interactions in perceived contrast and perceived brightness. Vision Research, 37, 1141-1155, 1997. [pdf]

Zaidi, Q., DeBonet, J.S. and Spehar, B. Perceived grey-levels in complex configurations. Recent Progress in Color Science, Eschbach, R. and Braun, K. (eds.), Imaging Science & Technology, 97-100, (1997).

Spehar, B., DeBonet, J.S. and Zaidi, Q. Brightness induction from uniform and complex surrounds: a general model. Vision Research, 36, 1893-1906, 1996.

Zaidi, Q. and Zipser, N. Induced contrast from radial patterns. Vision Research, 33, 1281-1286, 1993.

Zaidi, Q., Yoshimi, B., Flanigan, N. and Canova, A. Lateral interactions within color mechanisms in simultaneous induced contrast. Vision Research, 32, 1695-1707, 1992.

Zaidi, Q., Yoshimi, B. and Flanigan, J. The influence of shape and perimeter-length on induced color contrast. J. Opt. Soc. Am., A8, 1810-1817, 1991. 

Zaidi, Q. Apparent brightness in complex displays: A reply to Moulden and Kingdom. Vision Research, 30, 1253-1255, 1990. 

Zaidi, Q. Local and distal factors in visual grating induction. Vision Research, 29, 691-697, 1989.

Krauskopf, J., Zaidi, Q. and Mandler, M.B. Mechanisms of simultaneous color induction. J. Opt. Soc. Am., A3, 1752-1757, 1986.

Krauskopf, J. and Zaidi, Q. Induced desensitization. Vision Research, 26, 759-762, 1986.


  • Color Adaptation
Shapiro, A., Beere, J. and Zaidi, Q. Time course of adaptation stages in the S cone color system. Vision Research, (In press).

Shapiro, A., Beere, J. and Zaidi, Q. Stages of temporal adaptation in the RG color system. Color Research and Application, 26, S43-S47, 2001. [pdf]

Zaidi, Q., Spehar, B. and DeBonet, J.S. Adaptation to textured chromatic fields. J. Opt. Soc. Am., A15, 23-32, 1998. [pdf]

Shapiro, A. and Zaidi, Q. The effect of prolonged temporal modulation on the differential response of color mechanisms. Vision Research, 32, 2065-2076, 1992.

Zaidi, Q., Shapiro, A. and Hood, D. The effect of adaptation on the differential sensitivity of the S-cone color system. Vision Research, 32, 1297-1318, 1992.

Zaidi, Q. Adaptation and color matching. Vision Research, 26, 1925-1938, 1986.


  • Color Mechanisms
Zaidi, Q. Decorrelation of L and M cone signals. J. Opt. Soc. Am., A14, 3430-3431, 1997. [pdf]

Zaidi, Q. Commentary on "Schrodinger, E. (1925) Uber der Verhaltnis der Vierfarben zur Dreifarbentheorie" Color Research and Application, 19, 37-40, 1994.

Zaidi, Q. Commentary on "Maxwell, J. C. (1860) On the theory of compound colours and the relations of the colours of the spectrum" Color Research and Application, 18, 270-272, 1993.

Zaidi, Q. Parallel and serial connections between human color mechanisms. In Applications of Parallel Processing in Vision, J. Brannan (Ed.), Elsevier, Amsterdam, 227-259, 1992.

Zaidi, Q. and Pokorny, J. Appearance of pulsed infrared light: second harmonic generation in the eye. Applied Optics, 27, 1064-1068, 1988.

Smith, V., Pokorny, J. and Zaidi, Q. How do sets of color matching functions differ? In Colour Vision: Physiology and Psychophysics, J. Mollon and L.T. Sharpe (Eds.), Academic Press Ltd., London, 1983.

Pokorny, J., Smith, V., Burns S., Elsner, A. and Zaidi, Q. Modeling Blue-Yellow Opponency, Proceedings of the Fourth International Congress, AIC. M. Richter (Ed.), Berlin, 1981.


  • Clinical Studies
Greenstein, V., Zaidi, Q., Hood, D., DeBonet, J.S., Spehar, B., Cideciyan, A. and Jacobson, S. Enhanced S Cone Syndrome: receptoral and post-receptoral analyses. Vision Research, 36, 3711-3722, 1996. Reprinted in OSA Trends in Optics and Photonics Series Vol. 11, Noninvasive Assessment of the Visual System, Yager, D. (ed.), (Optical Society of America, Washington, DC 1997).

Greenstein, V., Halevy, D, Zaidi, Q. and Ritch, R. Chromatic and achromatic system deficits in open-angle glaucoma. Vision Research, 36, 621-629, 1996. Reprinted in OSA Trends in Optics and Photonics Series Vol. 11, Noninvasive Assessment of the Visual System, Yager, D. (ed.), (Optical Society of America, Washington, DC 1997).

Greenstein, V., Shapiro, A., Hood, D and Zaidi, Q. Chromatic and luminance sensitivity in diabetes and glaucoma. J. Opt. Soc. Am., A10, 1785-1791, 1993.

Greenstein, V., Shapiro, A., Zaidi, Q. and Hood, D. Psychophysical evidence for post-receptoral sensitivity loss in diabetics. Invest. Ophthal. and Vis. Sc., 33, 2781-2790, 1992.

Zaidi, Q., Pokorny, J. and Smith, V. Sources of individual differences in anomaloscope equations for tritan defects. Clinical Vision Sciences, 4, 89-94, 1989.


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