Licht-im-Terrarium: Literaturdatenbank
Licht-im-Terrarium: Literaturdatenbank |
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van Hemmen, J. L. 2006, March 13—17 Indeterminacy and image improvement in snake infrared "vision''. Paper presented at American Physical Society. Added by: Sarina (2009-04-02 15:53:27) Last edited by: Sarina (2010-09-22 16:46:11) |
| Resource type: Proceedings Article BibTeX citation key: vanHemmen2006 View all bibliographic details  |
Categories: Englisch = English Keywords: Infrarot = Infrared, Schlangen = Snakes, Sehvermögen = Visual Perception Creators: van Hemmen Collection: American Physical Society |
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| Abstract |
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Many snake species have infrared sense organs located on their head that can detect warm-blooded prey even in total darkness. The physical mechanism underlying this sense is that of a pinhole camera. The infrared image is projected onto a sensory `pit membrane' of small size (of order mm^2). To get a neuronal response the energy flux per unit time has to exceed a minimum threshold; furthermore, the source of this energy, the prey, is moving at a finite speed so the pinhole substituting for a lens has to be rather large (˜1 mm). Accordingly the image is totally blurred. We have therefore done two things. First, we have determined the precise optical resolution that a snake can achieve for a given input. Second, in view of known, though still restricted, precision one may ask whether, and how, a snake can reconstruct the original image. The point is that the information needed to reconstruct the original temperature distribution in space is still available. We present an explicit mathematical model [1] allowing even high-quality reconstruction from the low-quality image on the pit membrane and indicate how a neuronal implementation might be realized. Ref: [1] A.B. Sichert, P. Friedel, and J.L. van Hemmen, TU Munich preprint (2005).
Added by: Sarina |