Title Information
Title
Conformal Shape Representation
Name: Personal
Name Part
Feiszli, Matthew D.
Role
Role Term: Text
creator
Origin Information
Copyright Date (keyDate="yes", encoding="w3cdtf")
2008
Physical Description
Extent
ix, 152 p.
digitalOrigin
born digital
Note
Thesis (Ph.D.) -- Brown University (2008)
Name: Personal
Name Part
Mumford, David
Role
Role Term: Text
director
Name: Personal
Name Part
Brock, Jeffrey
Role
Role Term: Text
reader
Name: Personal
Name Part
Geman, Stuart
Role
Role Term: Text
reader
Name: Corporate
Name Part
Brown University. Applied Mathematics
Role
Role Term: Text
sponsor
Genre (aat)
theses
Abstract
Representation and comparison of shapes is a central problem in computer vision. In this dissertation, we continue investigation of a relatively recent approach, based on conformal mapping, which was first introduced by Mumford and Sharon in 2006. We first study the way this representation encodes the geometry. One perceptually salient attribute of a shape is its medial axis. By careful study of the boundary derivatives of conformal maps, we demonstrate how our representation encodes a sort of continuous version of the medial axis. This line of work provides medial-axis-based variants of results like the Ahlfors distortion theorem, and also provides a new proof and refinement of the conjecture, attributed to Thurston and first proven by V. Markovic, that the nearest-point retraction map is 2-Lipschitz in the hyperbolic metrics. In addition, we obtain explicit estimates demonstrating how conformal maps encode the local Euclidean curvature of the boundary. The machinery involved in making our geometric estimates comes both from classical function theory and hyperbolic geometry. We next investigate the differential of the isomorphism between quasisymmetric circle maps and shapes; we obtain explicit formulas for the differential in terms of the Hilbert transform. We then apply our results to develop an adaptive compressor for plane curves based on the ``fingerprint'' construction explored by Sharon and Mumford. We demonstrate that our compressor is optimal on certain classes of functions.
Subject (Local)
Topic
conformal
Subject (Local)
Topic
medial axis
Subject (Local)
Topic
teichmuller
Subject (Local)
Topic
quasiconformal
Subject (Local)
Topic
compression
Subject (Local)
Topic
hyperbolic
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/875029")
Topic
Conformal geometry
Subject (FAST) (authorityURI="http://id.worldcat.org/fast", valueURI="http://id.worldcat.org/fast/1115245")
Topic
Shapes
Record Information
Record Content Source (marcorg)
RPB
Record Creation Date (encoding="iso8601")
20091218
Language
Language Term: Code (ISO639-2B)
eng
Language Term: Text
English
Identifier: DOI
10.7301/Z0JS9NQN
Access Condition: rights statement (href="http://rightsstatements.org/vocab/InC/1.0/")
In Copyright
Access Condition: restriction on access
Collection is open for research.
Type of Resource (primo)
dissertations