uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Continuous extension in topological digital spaces
Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
2008 (English)In: Applied General Topology, ISSN 1576-9402, Vol. 9, no 1, 51-66 p.Article in journal (Refereed) Published
Place, publisher, year, edition, pages
2008. Vol. 9, no 1, 51-66 p.
National Category
Natural Sciences
URN: urn:nbn:se:uu:diva-96674OAI: oai:DiVA.org:uu-96674DiVA: diva2:171325
Available from: 2008-02-05 Created: 2008-02-05 Last updated: 2013-07-24Bibliographically approved
In thesis
1. Digital Geometry and Khalimsky Spaces
Open this publication in new window or tab >>Digital Geometry and Khalimsky Spaces
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Alternative title[sv]
Digital Geometri och Khalimskyrum
Abstract [en]

Digital geometry is the geometry of digital images. Compared to Euclid’s geometry, which has been studied for more than two thousand years, this field is very young.

Efim Khalimsky’s topology on the integers, invented in the 1970s, is a digital counterpart of the Euclidean topology on the real line. The Khalimsky topology became widely known to researchers in digital geometry and computer imagery during the early 1990s.

Suppose that a continuous function is defined on a subspace of an n-dimensional Khalimsky space. One question to ask is whether this function can be extended to a continuous function defined on the whole space. We solve this problem. A related problem is to characterize the subspaces on which every continuous function can be extended. Also this problem is solved.

We generalize and solve the extension problem for integer-valued, Khalimsky-continuous functions defined on arbitrary smallest-neighborhood spaces, also called Alexandrov spaces.

The notion of a digital straight line was clarified in 1974 by Azriel Rosenfeld. We introduce another type of digital straight line, a line that respects the Khalimsky topology in the sense that a line is a topological embedding of the Khalimsky line into the Khalimsky plane.

In higher dimensions, we generalize this construction to digital Khalimsky hyperplanes, surfaces and curves by digitization of real objects. In particular we study approximation properties and topological separation properties.

The last paper is about Khalimsky manifolds, spaces that are locally homeomorphic to n-dimensional Khalimsky space. We study different definitions and address basic questions such as uniqueness of dimension and existence of certain manifolds.

Place, publisher, year, edition, pages
Uppsala: Matematiska institutionen, 2008. vii+47 p.
Uppsala Dissertations in Mathematics, ISSN 1401-2049 ; 54
Applied mathematics, Khalimsky topology, digital geometry, digital topology, Alexandrov space, digital surface, digital curve, digital manifold, continuous extension, smallest-neighborhood space, image processing, Tillämpad matematik
urn:nbn:se:uu:diva-8419 (URN)978-91-506-1983-6 (ISBN)
Public defence
2008-02-29, Häggsalen, Ångström Laboratory, 13:15
Available from: 2008-02-05 Created: 2008-02-05Bibliographically approved

Open Access in DiVA

No full text

Other links

By organisation
Department of Mathematics
Natural Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 221 hits
ReferencesLink to record
Permanent link

Direct link