Professor
                        Falmagne Endowed Chair in Mathematical Psychology
                        Department of Cognitive Sciences
                        University of California-Irvine
                        Irvine, CA 92697 
                        email: zpizlo at uci dot edu
                        Office: SSPA 2187
                      
                       Zyg's Conjecture:
                          veridical 3D vision is mathematically and
                          computationally so difficult that there is only one
                          way to do it. 
                      Once you accept this, it follows that all animals
                        (including us) that see the 3D world veridically (or
                        nearly so) use the same algorithm. A computer that can
                        also see veridically, must be using the algorithm that
                        is used by the human visual system. So, there is no
                        longer any need to wonder about whether computer vision
                        should emulate biological vision. It must. 
                      How Noether's theorem can be
                          applied in the case of 3D vision to derive shape
                          constancy as a psychophysical conservation law.
                      Conclusions from the
                        review of "Making a machine...", by Adele Diederich
                        published in the Journal of Mathematical Psychology
                      Read
                          the entire review.
                      "What
                          role does symmetry play in the perception of 3D
                          objects?" - see our blog on the Oxford University
                        Press Web site. 
                      "Questions
                          about symmetry and visual perception" - tumblr on
                        the Oxford University Press Web site. 
                      When Gestaltists
                          stated that "the whole is different from the sum of
                          its parts" they meant that the visual system is not
                          linear. Recall that in a linear system, the
                        response to a linear combination of inputs is a linear
                        combination of the responses to the individual inputs.
                        This is not the case in vision. See the demo
                        (courtesy of Prof.
                          Tadamasa Sawada), which shows that the percept of
                        a 2D hexagon and of a 2D "Y junction" cannot explain the
                        percept of a 3D cube.
                      My work is directed by exploring new ideas rather than
                      following established views. In this approach, rational
                      arguments are as important for me as experimental results.
                      The emphasis on principled reasoning means that in my
                      view, cognitive psychology is not a bag of tricks; Neither
                      is my research. A list of my most important contributions
                      is provided below (in chronological order):
                       1992 - formulated perspective invariants thereby
                        providing the first model-based invariants in vision
                       1994 - proposed a new theory of shape constancy that
                        is NOT based on "taking slant into account"
                       1995 - developed a pyramid model explaining the
                        speed-accuracy trade-off in vision
                      1997 - explained the role of the calibrated camera
                        model in shape perception 
                       1999 - demonstrated shape constancy for solid shapes
                        and explained the apparent controversy between Rock's
                        and Biederman's results
                       2000 - developed a pyramid model that shows how human
                        beings solve the Traveling Salesman Problem (TSP)
                       2000 - contributed to the rediscovery of Wertheimer's
                        phi motion 
                       2001 - published a theoretical paper on inverse
                        problems in vision, making it clear that a priori
                        constraints are at least as important as the information
                        in the retinal image
                      2001 - provided a new criterion for classifying
                        illusions as important or unimportant
                       2005 - discovered a new binocular phenomenon showing
                        that a priori 3D shape constraints are more
                        important than binocular disparity
                       2006 - developed a TSP model that emulates human
                        visual attention and eye movements
                       2008 - published the first coherent treatment of the
                        history of shape perception
                       2009 - introduced a new theory of 3D shape perception
                        based on symmetry, compactness and planarity constraints
                      2009 - contributed to the demonstration that the
                        experimental method that uses an adjustable elliptical
                        probe to measure perception of local surface orientation
                        (slant and tilt) is fundamentally flawed
                       2011 - developed a new Bayesian theory of the
                        veridical binocular perception of symmetrical shapes
                        that emphasizes the role played by stereoacuity
                      2011 - demonstrated that a
                          priori constraints are more important in
                        achieving reliable shape constancy than depth cues
                       2011 - published psychophysical results on the
                        transfer of skilled movement that suggested that the
                        motor system has a pyramidal architecture, very much
                        like the architecture of the visual system
                       2012 - modeled the veridical recovery of 3D scenes and
                        3D figure-ground organization
                       2013 - showed that symmetry is the sine qua non
                        of shape
                       2013 - developed a TSP model with a small human-like
                        working memory
                       2014 - published a new theory of 3D veridical vision
                       2014 - contributed to the discovery of new model-based
                        invariants for 3D, piecewise planar, symmetrical curves
                       2015 - showed that a perceived closed curve is the
                        shortest path in the log-polar representation (aka
                        complex logarithmic map) present in the primary visual
                        cortex (area V1) of primates
                       2016 - explained how 3D visual perception can be a
                        "hard science" because symmetry, the least-action
                        principle and the conservation laws operate in 3D vision
                      2016 - helped to explain 3D and 2D figure-ground
                        organization by using 3D symmetry and gravity a
                          priori constraints
                       
                      These milestones are described in a
                          little more detail in the Research
                          link. Links to open access papers are in Publications.
                        
                       You can see the demos
                        for the newest book.
                      To see how our robot solves figure-ground organization
                        problem and performs simple navigations tasks go to Yunfeng's
                        web site and to the VSS
                          demo site. Check also demos on Tada's
                          web site