Fred Kingdom: Research Overview

I am interested in the relationship between the initial stages of vision that detect local features such as edges, bars and surface markings, and intermediate stages that link up those features to form contours, textures and surfaces. A full understanding of this process involves research in a number of domains, including spatial vision, colour vision, stereopsis, texture perception, brightness & lightness perception and transparency. I primarily use psychophysical methods, but also image processing and fMRI. Click on the icons below for details about each project.


reviews Review articles   Palamedes Palamedes toolbox   Illusions Illusions  
contour shape perception Contour shape   Colour Image Database

Calibrated colour image database

  Transformation Icon Natural scenes

Colour and Intrinsic Images

Colour, shadows and shading   Texture histogram statistics Texture statistics   Brightness lightness and transparency Brightness, lightness and transparency
Colour and global processing

Colour and global processing

  Texture gradient detection Texture gradients   Stereoscopic surface perception Stereo- surface perception
Colour and Stereopsis Colour and stereopsis   Basic colour mechanisms Basic colour mechanisms   Symmetry Symmetry




Review articles



  • Chirimuuta, M. & Kingdom, F. A. A. (2015). The uses of colour vision: ornamental, practical and theoretical. Mind & Machines, 25(2), 213-229.
  • Kingdom F. A. A. (2015). Visual Illusions, Models of. In Encyclopedia of Computational Neuroscience, by Jaeger D, Jung R (Eds.), Vol. 4, pp. 3072-3087. Springer, New York, Heidelberg, Dordrecht, London.
  • Kingdom, F. A. A. (2013). Brightness and Lightness. In The New Visual Neurosciences, by J. S. Werner & L. M. Chalupa (eds). MIT Press: Cambridge, MA.
  • Kingdom, F. A. A. (2012) Psychophysics. In Encyclopedia of Human Behavior, 2nd Edition, by V. S. Ramachandran (ed.). Academic Press, an imprint of Elsevier.
  • Kingdom, F. A. A. (2011). Lightness, Brightness and Transparency: A quarter century of new ideas, captivating demonstrations and unrelenting controversy. Vision Research, 51, 652-673.[PDF]
  • Kingdom, F. A. A. (2008) Perceiving light versus material [Invited review]. Vision Research, 48, 2090-2105. [PDF]
  • Shevell, S. K. & Kingdom, F. A. A. (2008). Color in complex scenes. Annual Review of Psychology, 59, 143-166.[PDF]





  • Yoonessi, A., Gheorghiu, E. & Kingdom, F. A. A. (2008) The Leaning Tower Illusion: orientation contrast or perspective distortion ? Reply to Maniatis. Perception, 37, 1773-1775.[PDF]
  • Kingdom, F. A. A., Yoonessi, A. & Gheorghiu, E. (2007a). Leaning Tower Illusion Scholarpedia.
  • Kingdom, F. A. A., Yoonessi, A. & Gheorghiu, E. (2007b). The Leaning Tower illusion: a new illusion of perspective. Perception, 36, 475-477.[PDF]

    contour shape perception

    Contour shape



    The shape-frequency and shape-amplitude after-effects

    Open one of the movies below and fixate the centre spot. After about a minute the movie will stop and you will see two stationary contours. Do you notice a difference in their perceived shape ? The two contours are identical, yet most observers see a difference in shape frequency or shape-amplitude.

    The shape frequency after-effect is the shape analog of the well-known spatial frequency after-effect found with luminance gratings. The shape amplitude after-effect might be thought of as the shape analog of the luminance contrast after-effect: the reduction in apparent contrast of a luminance grating one observes after adaptation to a high contrast grating. However, whereas the luminance contrast after-effect is uni-directional, i.e. adaptation only ever reduces the apparent contrast of the test, the shape-amplitude after-effect is bi-directional, i.e. adaptation causes higher amplititude tests to appear higher in amplitude and lower amplitude tests to appear lower in amplitude.

    We are currently using the shape-frequency and shape amplitude after-effects to explore the mechanisms of contour-shape and texture-shape perception.


    Shape-frequency after-effect QuickTimeMovie WinMediaPlayerMovie
    Shape-amplitude after-effect QuickTimeMovie WinMediaPlayerMovie
      [MOV - 4MB] [AVI-8MB]
      Quick Time Movie Win Media Player


    The movies below accompany the paper Gheorghu & Kingdom (2009). Each shows the simulated effect of a different contour segment/gap length on the response of a curvature detector that multiplies its '1st-stage' inputs.

    QuickTimeMovie QuickTimeMovie QuickTimeMovie QuickTimeMovie QuickTimeMovie


    Other papers on contour-shape processing are:



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    Transformation Icon

    Natural scenes



    How sensitive are we to transformations in natural scenes? Some transformations, such as the affine transformations of translation, rotation and scaling, and photometric transformations in mean luminance and contrast, are part of our natural visual experience. Others, such as the addition of noise, are not. We have measured thresholds for detecting a range of transformations, measured in terms of the the Euclidean distance of pixel intensities. The results show that humans are most sensitive to the transformations that are least likely to be experienced in everyday vision: see Kingdom, Field & Olmos (2007). Other projects have dealt with sensitivity to uniform colour changes in natural scene and the spatio-chromatic structure of natural scenes.


  • Jennings, B. J., Wang, K, Menzies, S. & Kingdom, F. A. A. (2015). Detection of chromatic and luminance distortions in natural scenes. Journal of the Optical Society of America A, 32(9): 1613-1622.
  • Yoonessi, A. & Kingdom, F. A. A. (2009) Dichoptic difference thresholds for uniform color changes applied to natural scenes. Journal of Vision,9(2):3, 1-12.
  • Yoonessi, A., Kingdom, F. A. A. & Alqawlaq, S. (2008) Is color patchy ? Journal of the Optical Society of America A, 25, 1330-1338.[PDF]
  • Yoonessi, A. & Kingdom, F. A. A. (2008) Comparison of sensitivity to color changes in natural and phase-scrambled scenes. Journal of the Optical Society of America A, 25, 676-684.[PDF]
  • Kingdom, F. A. A., Field, D. J. & Olmos, A. (2007) Does spatial invariance result from insensitivity to change? Journal of Vision, 7(14):11, 1-13,
  • Johnson, A. P., Kingdom, F. A. A. & Baker, C. L. Jr. (2005) Spatiochromatic statistics of natural scenes: First- and second-order information and their correlational structure. Journal of the Optical Society of America A, 22, 2050-2059. [PDF]

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    Colour and Intrinsic Images

    Colour, shadows and shading


    The colour-luminance plaid c, formed by combining the luminance grating a with the purple-green chromatic grating b, gives the impression of a curtain folded in depth and illuminated obliquely. This is an example of 3D-shape-from-shading that is triggered by colour contrast. When a second purple-green grating is added in alignment with the luminance grating, as in d, the perception of 3D shape-from-shading is eliminated. I refer to the capacity of colour variations to enhance and suppress 3D shape-from-shading as the ‘colour shading effect’.

    The colour shading effect reveals two built-in assumptions: a) chromatic variations, and those luminance variations that are spatially aligned with them, arise from surfaces; b) pure, or near-pure luminance variations, i.e. those non-aligned with chromatic variations, arise from inhomogenous illumination, such as shading. The colour-shading effect is the first evidence that the visual system has prior knowledge about the chromatic-luminance structure in natural scenes, and uses this knowledge to parse the image into surface and illumination.



  • Chirimuuta, M. & Kingdom, F. A. A. (2015). The uses of colour vision: ornamental, practical and theoretical. Mind & Machines, 25(2), 213-229.
  • Kingdom, F. A. A. (2011). Illusions of colour and shadow. Ch. in New Directions in Colour Studies, by C. P. Biggam, C. Hough, C. J. Kay & D. R. Simmons (eds.). John Benjamins Publishing Company. PDF available from author on request.
  • Kingdom, F. A. A. (2008) Perceiving light versus material. Vision Research, 48, 2090-2105. [PDF]
  • Kingdom, F. A. A. & Kasrai, R. (2006) Colour unmasks dark targets in complex displays. Vision Research, 46, 814-822.[PDF]
  • Kingdom, F. A. A., Wong, K., Yoonessi, A. & Malkoc (2006) Colour contrast influences perceived depth in combined shading and texture patterns. Spatial Vision, 19, 147-159.[PDF]
  • Kingdom, F. A. A., Rangwala, S. & Hammamji, K. (2005) Chromatic properties of the Colour shading Effect. Vision Research, 45, 1425-1437. [PDF]
  • Kingdom, F. A. A., Beauce C., Hunter L., (2004) Colour vision brings clarity to shadows, Perception, 33, 907 - 914. [PDF]
  • Olmos, A., Kingdom, F. A. A. (2004), A biologically inspired algorithm for the recovery of shading and reflectance images, Perception, 33, 1463 - 1473. [PDF]
  • Kingdom, F. A. A. (2003) Colour brings relief to human vision. Nature Neuroscience, 6, 641-644. [PDF]

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    Colour and global processing

    Colour and global processing



    Colour vision is useful for detecting camouflaged objects, such as red berries against green foliage. However, it does not follow that mechanisms involved in extracting global features of multi-element arrays are necessarily tuned for colour. We considered whether global motion and global stereopsis mechanisms are colour-tuned. In all our stimuli, multi-element "targets" were embedded in irrelevant "distractors", and target and distractors were either different in colour, termed 'colour-segregated', or were constructed from equal numbers of both colours, termed 'colour-nonsegregated'. For both the motion and stereopsis tasks, performance was no better in the colour-segregated than colour-nonsegregated conditions, unless the stimulus/task was designed in such a way that subjects could selectively attend to the target colour. We conclude that global motion and stereopsis mechanisms are not tuned for colour.


  • Li, H-C. O. & Kingdom, F. A. A. (2001) Motion-surface labeling by orientation, spatial frequency and luminance polarity in 3-D structure-from-motion. Vision Research, 41, 3873-3882. [PDF]
  • Kingdom, F. A. A. & Li, H-C. O. & MacAulay, E. J. (2001) The role of chromatic contrast and luminance polarity in stereoscopic segmentation. Vision Research, 41, 375-383.[PDF]
  • Pearson, P. M. & Kingdom, F. A. A. (2001) On the interference of task-irrelevant hue variation on texture segmentation. Perception, 30, 559-569.
  • Li, H-C. O. & Kingdom F. A. A. (2001) Segregation by colour/luminance does not necessarily facilitate motion discrimination in noise. Perception & Psychophysics, 63, 660-675.
  • Li, H-C. O. & Kingdom, F. A. A. (1999) Feature specific segmentation in perceived structure-from-motion. Vision Research, 39, 881-888.
  • Li, H-C. O. & Kingdom, F. A. A. (1998) Does segregation by colour/luminance facilitate the detection of structure-from-motion in noise? Perception, 27, 769-784.

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    Colour and Stereopsis

    Colour and stereopsis



    The goal of this project is to determine the strengths and limitations of colour vision when supporting stereoscopic depth perception. Our studies have shown that colour vision has its own mechanism for stereopsis (Simmons & Kingdom, 1997), but requires more contrast than its luminance-based counterpart to achieve an equivalent level of stereoscopic performance (Simmons & Kingdom, 1994, 1995; Kingdom & Simmons, 1996). Colour-based stereopsis also appears to be deficient when processing the depth of colour-contrast-modulated ("Chromatic 2nd-order") stimuli (Simmons & Kingdom, 1995) and is very poor at supporting stereoscopic surface perception (Kingdom, Simmons & Rainville, 1999). Finally, there is at least as much, if not more binocular summation of colour than luminance information (Simmons & Kingdom, 1998), suggesting that binocular summation and stereoscopic performance are not as closely correlated as previously thought.


  • Simmons, D. R. & Kingdom, F. A. A. (2002) Interactions between chromatic- and luminance-contrast-sensitive stereopsis mechanisms. Vision Research, 42, 1535-1545.[PDF]
  • Kingdom, F. A. A. & Simmons, D. R. (2000) The relationship between colour vision and stereoscopic depth perception (Invited Paper). Journal of the Society for 3-D Broadcasting and Imaging, 1, 10-19.
  • Kingdom, F. A. A., Simmons, D. R. & Rainville, S. J. M. (1999) On the apparent collapse of stereopsis in random-dot-stereograms at isoluminance. Vision Research, 39, 2127-2141. [PDF]
  • Simmons, D. R. & Kingdom, F. A. A. (1998) On the binocular summation of chromatic contrast. Vision Research, 38, 1063-1071.[PDF]
  • Simmons, D. R. & Kingdom, F. A. A. (1997) On the independence of chromatic and luminance stereopsis mechanisms. Vision Research, 37, 1271-1280.[PDF]


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    Basic colour mechanisms

    Basic colour mechanims



    Neurophysiological results show that neurons in the visual pathways and the early stages of cortical processing respond to both color and luminance information. This is perplexing since there is psychophysical evidence for independent colour and luminance detection mechanisms. The question arises as to how separate color and luminance mechanisms are derived from neural responses which confound the two. We addressed this problem by constructing computer models of cortical neurons encoding colour and luminance contrast (Kingdom & Mullen, 1995). We critically evaluated possible models for separating colour and luminance information in the cortex, and outlined the constraints under which they would operate. For example, we showed that considerable spatial summation would be required to derive a colour sensitive unit insensitive to luminance contrast, which implies a central limit to chromatic resolution.


    A second topic of interest has been the manner in which cones are fed into retinal P-cells. One view is that cones are selectively fed into P-cells, for example with L (long wavelength sensitive) cones fed into the centre and M (middle wavelength sensitive) cones fed into the surround. An alternative view is that cones are non-selectively fed into P-cells. In this view colour opponency arises by chance, specifically by chance differences in the relative numbers of L and M cones in centre and surround. This is termed the "hit and miss" hypothesis. We have shown that the rapid decline of colour contrast sensitivity with eccentricity can be explained by the "hit and miss" hypothesis, by combining others' measurements of the anatomical distributions of cones and P-cells across the primate retina, others' measurements of the receptive field sizes of P-cells, and our own simple mathematical model of cone-to-P-cell mapping (Mullen and Kingdom, 1996). Finally, we have recently shown that blue-yellow contrast sensitivity does not decline precipitously as does red-green contrast sensitivity, sugesting a quite different retinal architecture for the blue-yellow system (Mullen & Kingdom, 2002).


  • Mullen, K. T. & Kingdom, F. A. A. (2002) A differential distribution of red-green and blue-yellow colour vision across the visual field: evidence for different rules of connectivity? Visual Neuroscience, 19, 1-10.
  • Mullen, K. T. & Kingdom, F. A. A. (1996) Losses in peripheral color sensitivity predicted from 'hit and miss' post-receptoral cone connections. Vision Research, 36, 1995-2000.
  • Kingdom, F. A. A. & Mullen, K. T. (1995) Separating color and luminance information in the visual system. Spatial Vision, 9, 191-219.

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    Texture gradient detection

    Texture gradient detection



    Texture gradients can arise in the retinal image of any textured surface because of perspective, and are useful for determining surface shape. Orientation gradients appear to be particularly important. We were the first to measure the Orientation Modulation Function (OMF), which describes how sensitivity to a sinusoidal modulation of orientation depends on modulation, or "texture", spatial frequency (Kingdom, Keeble & Moulden, 1995). More recent experiments have shown that, for example, two superimposed orientation-modulated textures segment when differing by as little as an octave in luminance spatial frequency (Kingdom & Keeble, 2000). We have also shown that texture-orientation mechanisms pool colour and luminance carrier information (Pearson & Kingdom, 2002).


    An important question concerns whether different types of texture gradients, such as orientation modulated (OM), frequency modulated (FM) and contrast modulated (CM) textures are processed by different or common mechanisms. Recent cross-facilitation experiments support the idea of separate mechanisms (Kingdom, Hayes & Prins, 2003). Prins & Kingdom (2002), using an adaptation paradigm, have qualified this result by showing that what is "different" is the carrier tuning of each Filter-Rectify-Filter mechanism, which is selected to maximize the response to the particular texture modulation under investigation. Below are examples of OM and FM textures.

    Texture Gradient I
    Texture Gradient II



  • Johnson, A. P., Prins, N., Kingdom, F. A. A. & Baker, C. L. Jr. (2007) Ecologically valid combinations of first- and second-order surface markings facilitate texture discrimination. Vision Research, 47, 2281-2290.[PDF]
  • Motoyoshi, I. & Kingdom, F. A. A. (2007) Differential roles of contrast polarity reveal two streams of second-order visual processing. Vision Research, 47, 2047-2054.[PDF]
  • Prins, N. & Kingdom, F. A. A. (2006) Energy not features underlies texture-modulation detection. Perception, 35. 1035-1046.[PDF]
  • Kingdom, F. A. A., Prins, N. & Hayes, A. (2003) Mechanism independence for texture-modulation detection is consistent with a Filter-Rectify-Filter mechanism. Visual Neuroscience, 20, 65-76. [PDF]
  • Prins, N. & Kingdom, F. A. A. (2003) Detection and discrimination of texture modulations defined by orientation, frequency and contrast. Journal of the Optical Society of America A, 20, 401-410. [PDF]
  • Pearson, P. M. & Kingdom, F. A. A. (2002) Texture-orientation mechanisms pool colour and luminance. Vision Research, 42, 1547-1558. [PDF]
  • Prins, N. & Kingdom, F. A. A. (2002) Orientation- and frequency-modulated textures at low depths of modulation are processed by off-orientation and off-frequency texture mechanisms. Vision Research, 42, 705-713. [PDF]
  • Kingdom, F. A. A. & Keeble, D. R. T. (2000) Luminance spatial frequency differences facilitate the segmentation of superimposed textures. Vision Research, 40, 1077-1087.[PDF]
  • Kingdom, F. A. A. & Keeble, D. R. T. (1999) On the mechanism for scale invariance in orientation-defined textures. Vision Research, 39, 1477-1489. [PDF]
  • Arsenault, S. A., Wilkinson, F. & Kingdom, F. A. A. (1999) Modulation frequency and orientation tuning of second-order texture mechanisms. Journal of the Optical Society of America, 16, 427-435.[PDF]
  • Kingdom, F. A. A. & Keeble, D. R. T. (1996) A linear systems approach to the detection of both abrupt and smooth spatial variations in orientation-defined textures. Vision Research, 36, 409-420.[PDF]
  • Kingdom, F. A. A., Keeble, D. & Moulden, B. (1995) Sensitivity to orientation modulation in micropattern-based textures. Vision Research, 35, 79-91. [PDF]

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    Texture histogram statistics

    Texture statistics



    The most recent project (with Motoyoshi) determined the types of local pairwise relations in dense textures that we are most sensitive to, and the answer is the ones that are co-circular.

    Other projects have considered what are the texture statistics to which we are most sensitive. For example the textures below are constructed by dropping thousands of gabors of different orientations and spatial-frequencies, in specific relative numbers. If enough gabors are dropped, the texture approximates 1/f noise. By varying the contrast, phase and density of the gabors one can manipulate the 2nd (variance), 3rd (skew) and 4th (kurtosis) of the texture's pixel histogram, as well as the texture histogram after convolution with a wavelet filter. We found that observers were more sensitive to differences in the 4th moment, or kurtosis, between wavelet textures, than to differences in the 2nd (variance) and 3rd (skew) moments. This reinforces the importance of kurtosis as a texture statistic. Conventional Filter-Rectify-Filter models of texture segregation cannot segregate textures that differ only in kurtosis. A further stage of rectification and filtering is necessary.

    Texture Histogram I
    Texture Histogram II


    Synthetic wavelet-textures with low (left) and high (right) kurtosis respectively


  • Motoyoshi, I. & Kingdom, F .A .A. (2010). The role of co-circularity of local elements in texture perception. Journal of Vision, 10(1):3, 1-8.
  • Motoyoshi I., Kingdom F. A. A., (2003) Orientation opponency in human vision revealed by energy-frequency analysis, Vision Research, 43, 2197-2205. [PDF]
  • Kingdom, F. A. A., Hayes, A. & Field, D. J. (2001) Sensitivity to contrast histogram differences in synthetic wavelet-textures. Vision Research, 41, 585-598. [PDF]
  • Keeble, D. R. T., Kingdom, F. A. A. & Morgan, M. J. (1997) The orientational resolution of texture perception. Vision Research, 37, 2993-3007.[PDF]
  • Keeble, D. R. T, Kingdom, F. A. A, Moulden, B. & Morgan, M. J (1995) The detection of orientationally multimodal textures. Vision Research, 35, 1991-2005.[PDF]


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    Brightness lightness and transparency

    Lightness, brightness and transparency



    An important clue to the way the visual system processes the brightness (perceived luminance) and lightness (perceived reflectance) of surfaces comes from an examination of the errors it makes, for example simultaneous brightness contrast, or SBC. SBC has been known about since the time of Aristotle, but, remarkably, it still provokes controversy. Mark McCourt, Barbara Blakeslee, myself and others (and most undergraduate textbooks!) champion the idea that SBC is primarily a result of the operation of spatial bandpass mechanisms, traditionally referred to as manifesting "lateral inhibition", in conjunction with nonlinearities such as contrast normalization (for a recent model implementation see Blakeslee & McCourt, 1999, Vis. Res., 39, 4361). There is also evidence for an additional mechanism that discounts inhomogenous illumination, such as shadows, shading and achromatic transparency, and that as a result dramatically enhances SBC, such as in the figures recently popularised by Adelson, Logvinenko and others.


  • Huang, P.-C., Kingdom, F. A. A. & Hess, R. F. (2006) Only two phase mechanisms, ±cosine, in human vision. Vision Research, 46, 2069-2081.[PDF]
  • Kingdom, F. A. A. (2003) Levels of Brightness Perception. In Levels of Perception, by L. Harris & M. Jenkin (eds.), Springer-Verlag.
  • Kingdom, F. A. A. (2003) Comment on Gilchrist. In Levels of Perception, by L. Harris & M. Jenkin (eds.), Springer-Verlag.
  • Kingdom, F. A. A. (2003) Reply to Todorovic. In Levels of Perception, by L. Harris & M. Jenkin (eds.), Springer-Verlag.
  • Kasrai, R. & Kingdom, F. A. A. (2002) Achromatic transparency and the role of local contours. Perception, 31, 775-790.
  • Kasrai, R. & Kingdom, F. A. A. (2001) The precision, accuracy, and range of perceived achromatic transparency. Journal of the Optical Society of America, 18, 1-11. [PDF]
  • Kingdom, F. A. A. (1999) Old wine in new bottles. Some thoughts on Logvinenko's "Lightness induction revisited", [Guest editorial], Perception, 28, 929-934.[HTML]
  • Kasrai, R., Kingdom, F. A. A. & Peters, T. M. (1999) The perception of transparency in medical images. Proceedings 2nd International Conference in Medical Image Computing and Computer-Assisted Intervention - MICCAI 99', 726-733.
  • Kingdom, F. A. A., McCourt, M. E. & Blakeslee, B. (1997) In defence of "lateral inhibition" as the underlying cause of induced brightness phenomena. A reply to Spehar, Gilchrist & Arend. Vision Research, 37, 1039-1044.
  • Kingdom, F. A. A., Blakeslee, B. & McCourt, M. E. (1997) Brightness with and without perceived transparency: when does it make a difference? Perception 26, 493-506.
  • Kingdom, F. A. A. (1997) Simultaneous contrast: the legacies of Hering and Helmholtz [Guest editorial]. Perception 26, 673-677.
  • McCourt, M. E., Blakeslee, B. & Kingdom, F. A. A. (1997) The effect of perceived transparency on brightness judgements. Proceedings of the Society for Imaging Science and Technology: Optics and Imaging in the Information Age, 42-50.
  • Kingdom, F. A. A. (1997) Simultaneous contrast: the legacies of Hering and Helmholtz [Guest editorial]. Perception, 26, 673-677.
  • McCourt, M. E. & Kingdom, F. A. A. (1996) Facilitation of luminance grating detection by induced gratings. Vision Research, 36, 2563-2573. [PDF]
  • Kingdom, F. A. A. & Whittle, P. (1996) Contrast discrimination at high contrasts reveals the influence of local light adaptation on contrast processing. Vision Research, 36, 817-829. [PDF]
  • Kingdom, F. & Moulden, B. (1992) A multi-channel approach to brightness coding. Vision Research, 32, 1565-1582.[PDF]
  • Kingdom, F. & Moulden, B. (1991) White's effect and assimilation. Vision Research, 31, 151-159. [PDF]
  • Kingdom, F. & Moulden, B. (1991) A model for contrast discrimination with incremental and decremental test patches. Vision Research, 31, 851-858.[PDF]
  • Moulden, B. & Kingdom, F. (1991) The local border mechanism in brightness induction. Vision Research, 31, 1999-2008. [PDF]
  • Moulden, B. & Kingdom, F. (1990) The mechanisms involved in brightness induction effects: a reply to Zaidi. Vision Research, 30, 1247-1252.[PDF]
  • Moulden, B. & Kingdom, F. (1990) Light-dark anisotropies in the Craik-Cornsweet-O'Brien illusion and a new model of brightness perception. Spatial Vision, 5, 101-121.
  • Moulden, B. & Kingdom, F. (1989) White's Effect: a dual mechanism. Vision Research, 29, 1245-1256.[PDF]

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    Stereoscopic surface perception

    Stereoscopic surface perception



  • Kingdom, F. A. A., Ziegler, L. R. & Hess, R. F. (2001) Luminance spatial scale facilitates stereoscopic depth segmentation. Journal of the Optical Society of America, 18, 993-1002.
  • Ziegler, L. R., Hess, R. F. & Kingdom, F. A. A. (2000) Global factors that determine the maximum disparity for seeing cyclopean surface shape. Vision Research, 40, 493-502.[PDF]
  • Ziegler, L. R., Kingdom, F. A. A. & Hess, R. F. (2000) Local luminance factors that determine the maximum disparity for seeing cyclopean surface shape. Vision Research, 40, 1157-1165. [PDF]
  • Hess, R. F., Kingdom, F. A. A. & Ziegler, L. R. (1999) On the relationship between the spatial channels for luminance and disparity processing. Vision Research, 39, 559-568.

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    Symmetry perception



    This research was carried out as part of Stephane Rainville's PhD thesis.

  • Rainville, S. J. M. & Kingdom, F. A. A. (2002) Scale invariance is driven by stimulus density. Vision Research, 42, 351-367.[PDF]
  • Rainville, S. J. M. & Kingdom, F. A. A. (2000) The role of oriented spatial filters in the perception of mirror symmetry: psychophysics and modeling. Vision Research, 40, 2621-2644.[PDF]
  • Rainville, S. J. M. & Kingdom, F. A. A. (1999) Spatial-scale contribution to the detection of mirror symmetry in fractal noise. Journal of the Optical Society of America, 16, 2112-2122.

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