Continuous extension in topological digital spaces

Authors

  • Erik Melin Uppsala University

DOI:

https://doi.org/10.4995/agt.2008.1869

Keywords:

Khalimsky topology, Digital geometry, Alexandrov space, Continuous extension

Abstract

We give necessary and sufficient conditions for the existence of a continuous extension from a smallest-neighborhood space (Alexandrov space) X to the Khalimsky line. Using this result, we classify the subsets A  X such that every continuous function A ! Zbcan be extended to all of X. We also consider the more general case ofbmappings X ! Y between smallest-neighborhood spaces, and prove abdigital no-retraction theorem for the Khalimsky plane.

Downloads

Download data is not yet available.

Author Biography

Erik Melin, Uppsala University

Department of Mathematics

References

P. Alexandrov, Diskrete R¨aume. Mat. Sb. 2 (1937), 501–519.

L. Boxer, Digitally continuous functions, Pattern Recognition Lett. 15 (1994), 833–839. http://dx.doi.org/10.1016/0167-8655(94)90012-4

U. Eckhardt and L. J. Latecki, Topologies for the digital spaces Z2 and Z3 Computer Vision and Image Understanding 90 (2003), 295–312. http://dx.doi.org/10.1016/S1077-3142(03)00062-6

G. T. Herman, Geometry of digital spaces, Applied and Numerical Harmonic Analysis. Birkhäuser Boston Inc., Boston, MA, 1998.

G. T. Herman and D. Webster, A topological proof of a surface tracking algorithm, Computer Vision, Graphics, and Image Processing 23 (1983), 162–177. http://dx.doi.org/10.1016/0734-189X(83)90110-X

E. Khalimsky, Topological structures in computer science, J. Appl. Math. Simulation 1 (1987), 25–40.

E. Khalimsky, R. Kopperman and P. R. Meyer, Computer graphics and connected topologies on finite ordered sets, Topology Appl. 36 (1990), 1–17. http://dx.doi.org/10.1016/0166-8641(90)90031-V

C. O. Kiselman, Digital jordan curve theorems, In G. Borgefors, I. Nystr¨om, and G. Sanniti di Baja, editors, Discrete Geometry for Computer Imagery, volume 1953 of Lecture Notes in Computer Science, pages 46–56, 2000.

C. O. Kiselman, Digital geometry and mathematical morphology. Lecture notes, Uppsala University, 2004. Available at www.math.uu.se/~kiselman.

Reinhard Klette, Topologies on the planar orthogonal grid, in 6th International Conference on Pattern Recognition (ICPR’02), volume II, pages 354–357, 2002.

T. Y. Kong, Topological adjacency relations on Zn,Theoret. Comput. Sci. 283 (2002), 3-28. http://dx.doi.org/10.1016/S0304-3975(01)00050-0

T. Y. Kong, The Khalimsky topologies are precisely those simply connected topologies on Zn whose connected sets include all 2n-connected sets but no (3n− 1)-disconnected sets, Theoret. Comput. Sci. 305 (2003), 221–235. http://dx.doi.org/10.1016/S0304-3975(02)00710-7

T. Y. Kong, R. Kopperman and P. R. Meyer, A topological approach to digital topology, Amer. Math. Monthly 98 (1991), 901–917. http://dx.doi.org/10.2307/2324147

T. Y. Kong and A. Rosenfeld, Digital topology: Introduction and survey, Comput. Vision Graph. Image Process. 48 (1989), 357–393. http://dx.doi.org/10.1016/0734-189X(89)90147-3

R. Kopperman, Topological digital topology. In Ingela Nystr¨om, Gabriella Sanniti di Baja, and Stina Svensson, editors, DGCI, volume 2886 of Lecture Notes in Computer Science, pages 1–15. Springer, 2003.

V. A. Kovalevsky, Finite topology as applied to image analysis, Comput. Vision Graph. Image Process. 46 (1989), 141–161. http://dx.doi.org/10.1016/0734-189X(89)90165-5

E. Melin, How to find a Khalimsky-continuous approximation of a real-valued function, In Reinhard Klette and Jovisa Zunic, editors, Combinatorial Image Analysis, volume 3322 of Lecture Notes in Computer Science, pages 351–365, 2004.

E. Melin, Digital straight lines in the Khalimsky plane, Math. Scand. 96 (2005) 49–62.

E. Melin, Extension of continuous functions in digital spaces with the Khalimsky topology, Topology Appl. 153 (2005) 52–65. http://dx.doi.org/10.1016/j.topol.2004.12.004

R. E. Stong, Finite topological spaces, Trans. Amer. Math. Soc. 123 (1966) 325–340. http://dx.doi.org/10.1090/S0002-9947-1966-0195042-2

Downloads

How to Cite

[1]
E. Melin, “Continuous extension in topological digital spaces”, Appl. Gen. Topol., vol. 9, no. 1, pp. 51–66, Apr. 2008.

Issue

Section

Regular Articles