VisionScienceList: PHD-student, Utrecht University, Netherlands

From: Astrid Kappers (a.m.l.kappers@phys.uu.nl)
Date: Thu Mar 22 2001 - 04:24:04 PST

  • Next message: Astrid Kappers: "VisionScienceList: Postdoc, Utrecht University, Netherlands"

    At the Helmholtz Instituut
    http://www.phys.uu.nl/~wwwpm/HumPerc/index.html#vacancy), department
    Physics of Man, of Utrecht University (The Netherlands) we have a
    PhD-student position available for a period of four years, starting in
    September 2001. The topic is "The structure of optical space under free
    viewing conditions". The lab is headed by Jan Koenderink and Astrid
    Kappers. Interested persons should contact one of us by e-mail
    (a.m.l.kappers@phys.uu.nl, j.j.koenderink@phys.uu.nl).

    Short project description:

    Visual observers are aware of the structure of their surrounding space. For
    the stationary observer this optical space differs systematically from
    physical space. The deviations are indeed surprisingly large. Most of our
    present understanding has been gained under extremely reduced experimental
    conditions, such as an evironment reduced to a small number of dim point
    sources in otherwise complete darkness, fixed head and body posi- tions,
    sometimes even restrictions on eye movements. In such circumstances
    observers are forced to rely on binocular disparity only. Although one
    might expect simple results in such cases, there is actually no
    satisfactory consensus in the literature as to the structure of human
    optical space.
            We propose to deviate from this tradition, in that we will use a
    structured environment and allow the observer free head movements.
    Moreover, whereas the literature focusses on the metrical structure, we
    propose to address the more fundamental projective structure of optical
    space. There exist sufficient indications from the literature that a
    satisfactory metric model of optical space might be utopic. We have found
    indications that its projective structure might be quite tight though.
    Because we address the projective rather than the metric structure, we need
    novel psychophysical methods, such as exocentric pointing and collinearity
    or coplanarity judgements. In pilot experiments we have found these methods
    to be viable and effective.
           The goal is to arrive at a coherent geometrical model of human
    optical space, possibly not fully metrical and quite likely dependent upon
    the physical structure of the observer's environment.

    Helmholtz Instituut, Department Physics of Man
    Princetonplein 5
    3584 CC Utrecht
    The Netherlands



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