Ph.D. thesis available

[rolf@cs.rug.nl]

                Ph.D. thesis available by ftp
                -----------------------------

             Multilayer Dynamic Link Networks for 
           Establishing Image Point Correspondences 
                and Visual Object Recognition


                      by Rolf P. W\"urtz

                         
    FTP-host: archive.cis.ohio-state.edu
    FTP-filename: /pub/neuroprose/wuertz.ps.Z
    URL: ftp://archive.cis.ohio-state.edu/pub/neuroprose/Thesis/wuertz.ps.Z

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    URL: http://www.cs.rug.nl/~rolf/wuertz.thesis.ps.gz


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ABSTRACT:
---------

The major tasks for automatic object recognition are segmentation of
the image and solving the correspondence problem, i.e.\ reliably
finding the points in the image that belong to points in a given model.
Once these correspondences are found, the local similarities can be
used to assign one model out of a set of known ones to the image.

This work defines a suitable representation for models and images based
on a multiresolution transform with Gabor wavelets.The properties of
such transforms are discussed in detail.

Then a neural network with dynamic links and short-term activity
correlations is presented that estimates these correspondences in
several layers coarse-to-fine. It is formalized into a nonlinear
dynamical system. Simulations show its capabilities that extend
earlier systems by background invariance and faster convergence.

Finally, the central procedures of the network are put into an
algorithmic form, which allows fast implementation on conventional
hardware and uses the correspondences for the successful recognition
of human faces out of a gallery of 83 independent of their hairstyle.
This demonstrates the potential for the recognition of objects 
independently of the background, which was not possible with earlier 
systems.


KEYWORDS:
---------

Neural network, dynamic link architecture, correspondence problem, 
object recognition, face recognition, coarse-to-fine strategy, 
wavelet transform, image representation

CONTENTS:
---------

Abstract..........................................1
Preface...........................................3
Acknowledgements..................................5
Contents..........................................7
1. Introduction..................................13
2. Wavelet Preprocessing.........................25
3. Representation of Images and Models...........49
4. Hierarchical Dynamic Link Matching............65
5. Algorithmic Pyramid Matching..................89
6. Hierarchical Object Recognition..............109
7. Discussion...................................119
8. Bibliography.................................127
9. Anhang in deutscher Sprache..................141
Index...........................................153


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Enjoy reading (at least) as much as I enjoyed writing!

Rolf

+----------------------------------+---------------------------------------+
| Rolf P. W"urtz                   | Email: rolf at cs.rug.nl                 |
| Department of Computer Science   |                                       |
| University of Groningen          | Phone: +31 50 63-6496  or             |
| P.O. Box 800                     |                 -3939  (dept. secr.)  |
| 9700 AV Groningen                | Fax:   +31 50 63-3800                 |
| The Netherlands                  |                                       |
+----------------------------------+---------------------------------------+