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215
Towards an Architecture for Cognitive Vision using Qualitative SparioTemporal Representations and Abduction
 In Spatial Cognition III
, 2002
"... In recent years there has been increasing interest in constructing cognitive vision systems capable of interpreting the high level semantics of dynamic scenes. Purely quantitative approaches to the task of constructing such systems have met with some success. However, qualitative analysis of dyn ..."
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Cited by 32 (1 self)
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In recent years there has been increasing interest in constructing cognitive vision systems capable of interpreting the high level semantics of dynamic scenes. Purely quantitative approaches to the task of constructing such systems have met with some success. However, qualitative analysis of dynamic scenes has the advantage of allowing easier generalisation of classes of different behaviours and guarding against the propagation of errors caused by uncertainty and noise in the quantitative data. Our aim is to integrate quantitative and qualitative modes of representation and reasoning for the analysis of dynamic scenes. In particular, in this paper we outline an approach for constructing cognitive vision systems using qualitative spatialtemporal representations including prototypical spatial relations and spatiotemporal event descriptors automatically inferred from input data. The overall architecture relies on abduction: the system searches for explanations, phrased in terms of the learned spatiotemporal event descriptors, to account for the video data.
Topological Relations between Regions in R² and Z²
, 1993
"... Users of geographic databases that integrate spatial data represented in vector and raster models, should not perceive the differences among the data models in which data are represented, nor should they be forced to apply different concepts depending on the model in which spatial data are repre ..."
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Cited by 32 (2 self)
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Users of geographic databases that integrate spatial data represented in vector and raster models, should not perceive the differences among the data models in which data are represented, nor should they be forced to apply different concepts depending on the model in which spatial data are represented. A crucial aspect of spatial query languages for such integrated systems is the need mechanisms to process queries about spatial relations in a consistent fashion. This paper compares topological relations between spatial objects represented in a continuous (vector) space of ## and a discrete (raster) space of ZZ . It applies the 9intersection, a frequently used formalism for topological spatial relations between objects represented in a vector data model, to describe topological relations for bounded objects represented in a raster data model. We found that the set of all possible topological relations between regions in ## is a subset of the topological relations that can be realized between two bounded, extended objects in ZZ . At a
Towards a Qualitative Theory of Movement
 Int. Conf. on Spatial Information Theory, LNCS 988
"... The phenomenon of movement arises whenever the same object occupies different positions in space at different times. Therefore a theory of movement must contain theories of time, space, objects, and position. We provide a theoretical basis for describing movement events in terms of the conditions fo ..."
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Cited by 29 (0 self)
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The phenomenon of movement arises whenever the same object occupies different positions in space at different times. Therefore a theory of movement must contain theories of time, space, objects, and position. We provide a theoretical basis for describing movement events in terms of the conditions for their occurrence, which refer to the holding or not holding of various positional fluents at different times. For this we need to bring together a formal model of time with a formal model of space. By attending closely to the constraints imposed by continuity on the temporal behaviour of different fluents we develop theory of dominance, which enables us to generate ab initio the perturbation relation on the full set of positional relations. 1 Introduction The phenomenon of movement arises whenever the same object occupies different positions in space at different times. This bare definition already suggests the main ingredients of a theory of movement: 1. A theory of time, comprising (a) ...
Structuring Space with Image Schemata: Wayfinding in Airports as a Case Study
 In Proceedings of the International Conference on Spatial Information Theory
, 1997
"... . Wayfinding is a basic activity people do throughout their entire lives as they navigate from one place to another. In order to create different spaces in such a way that they facilitate people's wayfinding it is necessary to integrate principles of human spatial cognition into the design p ..."
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Cited by 27 (11 self)
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. Wayfinding is a basic activity people do throughout their entire lives as they navigate from one place to another. In order to create different spaces in such a way that they facilitate people's wayfinding it is necessary to integrate principles of human spatial cognition into the design process. This paper presents a methodology to structure space based on experiental patterns, called image schemata. It integrates cognitive and engineering aspects in three steps: (1) interviewing people about their spatial experiences as they perform a wayfinding task in the application space, (2) extracting the image schemata from these interviews and formulating a sequence of subtasks, and (3) structuring the application space (i.e., the wayfinding task) with the extracted image schemata. We use wayfinding in airports as a case study to demonstrate the methodology. Our observations show that most often image schemata are correlated with other image schemata in the form of imageschemat...
GQR – A Fast Reasoner for Binary Qualitative Constraint Calculi
"... GQR (Generic Qualitative Reasoner) is a solver for binary qualitative constraint networks. GQR takes a calculus description and one or more constraint networks as input, and tries to solve the networks using the path consistency method and (heuristic) backtracking. In contrast to specialized reasone ..."
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Cited by 26 (8 self)
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GQR (Generic Qualitative Reasoner) is a solver for binary qualitative constraint networks. GQR takes a calculus description and one or more constraint networks as input, and tries to solve the networks using the path consistency method and (heuristic) backtracking. In contrast to specialized reasoners, it offers reasoning services for different qualitative calculi, which means that these calculi are not hardcoded into the reasoner. Currently, GQR supports arbitrary binary constraint calculi developed for spatial and temporal reasoning, such as calculi from the RCC family, the intersection calculi, Allen’s interval algebra, cardinal direction calculi, and calculi from the OPRA family. New calculi can be added to the system by specifications in a simple text format or in an XML file format. The tool is designed and implemented with genericity and extensibility in mind, while preserving efficiency and scalability. The user can choose between different data structures and heuristics, and new ones can be easily added to the objectoriented framework. GQR is free software distributed under the terms of the GNU General Public License.
An Empirically Validated Model for Computing Spatial Relations
, 1995
"... In the last couple of decades increasingly sophisticated models for computing spatial relations have been developed. The approaches have mostly been based on introspection and have not been validated for their correctness. We therefore designed experimental studies to verify the crucial hypotheses o ..."
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Cited by 23 (2 self)
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In the last couple of decades increasingly sophisticated models for computing spatial relations have been developed. The approaches have mostly been based on introspection and have not been validated for their correctness. We therefore designed experimental studies to verify the crucial hypotheses of a proposed computational model for establishing spatial relationships between extended objects in 2D and 3D space. The main point of interest was to clarify the dependencies between angle, distance and shape when establishing projective relations. It appeared that the angular deviation plays the key role when applying relations of this class. The degree of deviation was dependent upon the extension of the reference object. After slight adjustments of the algorithm to the empirical outcome we were able to predict the experimental results and therefore to validate the proposed model.
ªWeighted Walkthroughs between Extended Entities for Retrieval by Spatial Arrangement,º
 IEEE Trans. Multimedia
"... Abstract—In the access to image databases, queries based on the appearing visual features of searched data reduce the gap between the user and the engineering representation. To support this access modality, image content can be modeled in terms of different types of features such as shape, texture, ..."
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Cited by 23 (4 self)
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Abstract—In the access to image databases, queries based on the appearing visual features of searched data reduce the gap between the user and the engineering representation. To support this access modality, image content can be modeled in terms of different types of features such as shape, texture, color, and spatial arrangement. An original framework is presented which supports quantitative nonsymbolic representation and comparison of the mutual positioning of extended nonrectangular spatial entities. Properties of the model are expounded to develop an efficient computation technique and to motivate and assess a metric of similarity for quantitative comparison of spatial relationships. Representation and comparison of binary relationships between entities is then embedded into a graphtheoretical framework supporting representation and comparison of the spatial arrangements of a picture. Two prototype applications are described. Index Terms—Image databases, retrieval by visual content, spatial relationships. I.
A relative orientation algebra with adjustable granularity
 IN: PROCEEDINGS OF THE WORKSHOP ON AGENTS IN REALTIME AND DYNAMIC ENVIRONMENTS (IJCAI
, 2005
"... The granularity of spatial calculi and the resulting mathematical properties have always been a major question in solving spatial tasks qualitatively. In this paper we present the Oriented Point Relation Algebra (OPRAm), a new orientation calculus with adjustable granularity. Since our calculus is a ..."
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Cited by 22 (3 self)
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The granularity of spatial calculi and the resulting mathematical properties have always been a major question in solving spatial tasks qualitatively. In this paper we present the Oriented Point Relation Algebra (OPRAm), a new orientation calculus with adjustable granularity. Since our calculus is a relation algebra in the sense of Tarski, fast standard inference methods can be applied. One of the major problems—depending on the environment, the robots ’ capabilities and the tasks to be solved—is the choice of the granularity of an applied calculus. To present, granularity had to be chosen at the start and could not be changed on the fly. In a dynamically changing environment under real time conditions it is necessary to choose a coarse but still adequate granularity of the spatial representation: only in that case irrelevant feature changes fail to trigger unnecessary inference steps. A qualitative, coarse abstraction suppresses tiny changes in the environment and leads to fast computation.
Progress in computational methods for representing geographical concepts
 International Journal of Geographical Information Science
, 1999
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Exploiting Qualitative Spatial Neighborhoods in the Situation Calculus
 In Spatial Cognition
, 2004
"... We present first ideas on how results about qualitative spatial reasoning can be exploited in reasoning about action and change. Current work concentrates on a line segment based calculus, the dipole calculus, and how its conceptual neighborhood structure can be applied in the situation calculus for ..."
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Cited by 19 (6 self)
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We present first ideas on how results about qualitative spatial reasoning can be exploited in reasoning about action and change. Current work concentrates on a line segment based calculus, the dipole calculus, and how its conceptual neighborhood structure can be applied in the situation calculus for reasoning qualitatively about relative positions in dynamic environments.