Klette, Reinhard2008-08-212008-08-212003Communication and Information Technology Research Technical Report 121, (2003)1178-3624http://hdl.handle.net/2292/2844You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site; http://citr.auckland.ac.nz/techreports/ under terms that include this permission. All other rights are reserved by the author(s).Incidence pseudographs (or the dual model of complexes based on a bounded-by relation) are popular models for pixels or voxels and relations between these. They allow a definition of a topological space, and combinatorial formulas characterize open and closed sets in this topology. K. Voss characterized in 1993 open regions in incidence pseudographs. This article reviews these results and provides also combinatorial formulas for closed regions.Copyright CITR, The University of Auckland. You are granted permission for the non-commercial reproduction, distribution, display, and performance of this technical report in any format, BUT this permission is only for a period of 45 (forty-five) days from the most recent time that you verified that this technical report is still available from the original CITR web site under terms that include this permission. All other rights are reserved by the author(s).https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htmTechnical ReportFields of Research::280000 Information, Computing and Communication Sciences