Koenderink J J, van Doorn A J, Kappers A M L, Lappin J S, 2002, "Large-scale visual frontoparallels under full-cue conditions" Perception 31(12) 1467 – 1475
Download citation data in RIS format
Large-scale visual frontoparallels under full-cue conditions
Jan J Koenderink, Andrea J van Doorn, Astrid M L Kappers, Joseph S Lappin
Received 24 October 2001, in revised form 13 August 2002
Abstract. We determined the curvature of apparent frontoparallels in a natural scene (a large lawn in broad daylight). Data on frontoparallels in these conditions are very sparse and reveal idiosyncratic curvatures of frontoparallels and irregular variation with distance. We used a method of bisection of linear segments indicated through pairs of stakes at angular separations (from the vantage point) of up to 120 deg. Distances of 2 m and 10 m (in the forward direction) were used. The bisection was carried out by the observer through maneuvering a radio-controlled vehicle carrying a third stake. Four observers participated in the experiment; they had no problems with the task and yielded mutually consistent results. We found that the frontoparallels are significantly curved and are concave towards the observer. Surprisingly, the sign of the curvature is opposite to that found when the frontoparallels are defined through an exocentric pointing task. Available theory (Luneburg's) does not predict this, but the theory is hardly applicable to the case of vision in natural scenes. This interesting discrepancy has not been reported before.
Full-text PDF size: 237 Kb
References 13 references, 1 with DOI links ()
Your computer (IP address: 126.96.36.199) has not been recognised as being on a network authorised to view the full text or references of this article. This content is part of our deep back archive. If you are a member of a university library that has a subscription to the journal, please contact your serials librarian (subscriptions information).