2026-09-21T23:43:41Z https://opus4.kobv.de/opus4-uni-passau/oai

oai:kobv.de-opus4-uni-passau:768 2025-08-13 bibliography:false doc-type:PhDThesis open_access ddc ddc:510

Curvature Detection by Integral Transforms Thomas Fink 510 Krümmung Wavelet-Transformation Shearlet Radon-Transformation Konturfindung Curvature Wavelet Shearlet Parabolic Radon transform Edge classification In various fields of image analysis, determining the precise geometry of occurrent edges, e.g. the contour of an object, is a crucial task. Especially the curvature of an edge is of great practical relevance. In this thesis, we develop different methods to detect a variety of edge features, among them the curvature. We first examine the properties of the parabolic Radon transform and show that it can be used to detect the edge curvature, as the smoothness of the parabolic Radon transform changes when the parabola is tangential to an edge and also, when additionally the curvature of the parabola coincides with the edge curvature. By subsequently introducing a parabolic Fourier transform and establishing a precise relation between the smoothness of a certain class of functions and the decay of the Fourier transform, we show that the smoothness result for the parabolic Radon transform can be translated into a change of the decay rate of the parabolic Fourier transform. Furthermore, we introduce an extension of the continuous shearlet transform which additionally utilizes shears of higher order. This extension, called the Taylorlet transform, allows for a detection of the position and orientation, as well as the curvature and other higher order geometric information of edges. We introduce novel vanishing moment conditions which enable a more robust detection of the geometric edge features and examine two different constructions for Taylorlets. Lastly, we translate the results of the Taylorlet transform in R^2 into R^3 and thereby allow for the analysis of the geometry of object surfaces. Universität Passau Passau Innstrasse 29, 94032 Passau Brigitte Forster-Heinlein Uwe Kähler Daniel Potts 2019-11-15 2020-01-17 PhDThesis Text urn:nbn:de:bvb:739-opus4-7684 application/pdf eng Creative Commons - CC BY-SA - Namensnennung - Weitergabe unter gleichen Bedingungen 4.0 International thesis.doctoral Universität Passau Passau Fakultät für Informatik und Mathematik 1 https://opus4.kobv.de/opus4-uni-passau/oai/container/index/docId/768 https://opus4.kobv.de/opus4-uni-passau/frontdoor/index/index/docId/768