Spatial Relationships Of Objects Research Articles

Spatial cognition and linguistic expression

This paper analyzes frames of reference involved in linguistic expression of spatial relations of objects, using an experimental method. Objects with and without intrinsic orientation are used as the figure object, and it is demonstrated that there exists in Japanese a phenomenon we call ‘figure-aligned mapping’, where the coordinate system on the figure object is projected onto the ground object. This is what previous studies have not reported or argued. We claim that this figure-aligned mapping belongs to the intrinsic frame of reference among the three (intrinsic, relative, and absolute) frames of reference proposed by Levinson, and some revision of his definition of the intrinsic frame is proposed so that figure-aligned mapping can be accommodated in it. The result of this study confirms the importance of the notion of coordinate system in the discussion of frames of reference.

The relationship between spatial abilities and representations of large-scale space in children—a structural equation modeling analysis

The relationship between spatial abilities and spatial representations of large-scale environments was examined with children between 7 and 12 years of age. Subjects were 172 2nd, 4th and 6th graders from different neighborhoods in Magdeburg, Germany. They completed paper-and-pencil forms of Piaget's Water-Level-Task, the Rod-and-Frame Test and the Mental-Rotations-Test. In addition children were asked to draw sketch maps of their neighborhood. Performance measures in the three spatial tests were modestly related to each other. There were close to zero correlations between most measures of cognitive mapping and spatial-test performance. An analysis with structural equation models confirmed a model with the two uncorrelated second-level spatial factors spatial ability and spatial representations of the environment. Results also indicate that each second-order spatial-ability factor consists of three subfactors, each representing one of the spatial tests. In contrast to previous studies, the results clearly support the distinction between (1) large-scale spatial tasks where the observer is part of the environment and cannot see the whole space of interest from one point of view, and (2) small-scale spatial tasks, on the other hand, where the spatial relations of objects can be seen at once. The implications of this distinction for our understanding of spatial cognition are discussed.

STRPN: a petri-net approach for modeling spatial-temporal relations between moving multimedia objects

A multimedia presentation model provides designers a tool to formally specify the temporal and spatial relationships of objects. The formality helps designers to communicate with others, to check the integrity of designs, and provides a chance to simulate the designs. Although much research has been devoted to this subject, to the best of our knowledge, no multimedia models are able to describe the spatial-temporal relations of moving objects that may refer to each other for computing displaying addresses. The addresses may be recomputed several times during the objects' lifetimes to reflect their movements. Without a formal model, designers are forced to specify the relationships in an ad hoc manner that causes misunderstanding and hampers integrity check. The check includes if an object gets its addresses in time from another object, if an object is displayed in the right places, etc. The difficulty of designing such a formal model lies in integrating temporal constraints of objects with a real-time address transferring mechanism. In this paper, we present an extended Petri-net model, which models concurrent relationships of objects with new places, transitions, and firing rules to transfer and transform addresses in real time. Its descriptive power and correctness is demonstrated by five patterns of multimedia presentations and a sample play scripts.

Perceptual constraints on implicit learning of spatial context

Invariant spatial relationships of objects may provide a rich source of contextual information. Visual context can assist localization of individual objects via an implicit learning mechanism, as revealed in the contextual cueing paradigm (Chun & Jiang, 1998). What defines a visual context? How robust is contextual learning? And is it perceptually constrained? Here we investigate whether both local context that surround a target, and long-range context that does not spatially coincide with a target, can influence target localization. In the contextual cueing task, participants implicitly learned a context by repeated exposure to items arranged in invariant patterns. Experiments 1 and 2 suggest that only local context facilitates target localization. However, Experiment 3 showed that long range context can prime target location when target and context are not separated by random information. Experiment 4 showed that grouping by colour does not affect contextual cueing, suggesting that spatial features play a more important role than surface features in spatial contextual cueing. In separate analyses, visual hemifield differences were found for learning and performance. In sum, the results indicate that implicit learning of spatial context is robust across noise and biased towards spatially grouped information.

Spatio-temporal composition of video objects: representation and querying in video database systems

A key characteristic of video data is the associated spatial and temporal semantics. It is important that a video model models the characteristics of objects and their relationships in time and space. J.F. Allen's (1983) 13 temporal relationships are often used in formulating queries that contain the temporal relationships among video frames. For the spatial relationships, most of the approaches are based on projecting objects on a two or three-dimensional coordinate system. However, very few attempts have been made formally to represent the spatio-temporal relationships of objects contained in the video data and to formulate queries with spatio-temporal constraints. The purpose of the work is to design a model representation for the specification of the spatio-temporal relationships among objects in video sequences. The model describes the spatial relationships among objects for each frame in a given video scene and the temporal relationships (for this frame) of the temporal intervals measuring the duration of these spatial relationships. It also models the temporal composition of an object, which reflects the evolution of object's spatial relationships over the subsequent frames in the video scene and in the entire video sequence. Our model representation also provides an effective and expressive way for the complete and precise specification of distances among objects in digital video. This model is a basis for the annotation of raw video.

Dealing with spatial relations for spatial objects with randomness in GIS

To design retrieval algorithm of spatial relations for spatial objects with randomness in GIS, this paper builds up the membership functions based on set theory idea, used for determination of topological spatial relations between random objects, such as between point and point, point and line or polygon, which provides theoretical basis for retrieving spatial relations between certain and random objects. Finally, this paper interprets detailed methods and steps of realizing them by means of some simple examples under the GIS's environment.

Hierarchical coding in the perception and memory of spatial layouts

Two experiments were performed to investigate the organization of spatial information in perception and memory. Participants were confronted with map-like configurations of objects which were grouped by color (Experiment 1) or shape (Experiment 2) so as to induce cognitive clustering. Two tasks were administered: speeded verification of spatial relations between objects and unspeeded estimation of the Euclidean distance between object pairs. In both experiments, verification times, but not distance estimations, were affected by group membership. Spatial relations of objects belonging to the same color or shape group were verified faster than those of objects from different groups, even if the spatial distance was identical. These results did not depend on whether judgments were based on perceptually available or memorized information, suggesting that perceptual, not memory processes were responsible for the formation of cognitive clusters.

Searching Images on the Basis of Color Homogeneous Objects and their Spatial Relationship

In this paper we introduce several techniques which characterize color homogeneous objects and their spatial relationships for a more precise and efficient content-based image searching. We first present a region growing technique for efficient color homogeneous object segmentation, and then we extend the 2-D string to express spatial signatures for an accurate description of spatial relationships of objects within an image. Several optimizations, including dominant color histogram clustering, have also been proposed for an efficient search engine implementation. The experimental results that we have drawn so far show that our content-based image searching techniques give a high precision while maintaining a very good recall rate.

3D Shape Inferencing and Modeling for Video Retrieval

We present a geometry-based indexing approach for the retrieval of video databases. It consists of two modules: 3D object shape inferencing from video data and geometric modeling from the reconstructed shape structure. A motion-based segmentation algorithm employing feature block tracking and principal component split is used for multi-moving-object motion classification and segmentation. After segmentation, feature blocks from each individual object are used to reconstruct its motion and structure through a factorization method. The estimated shape structure and motion parameters are used to generate the implicit polynomial model for the object. The video data is retrieved using the geometric structure of objects and their spatial relationship. We generalize the 2D string to 3D to compactly encode the spatial relationship of objects.

The influences of sex, rearing environment, and neonatal choline dietary supplementation on spatial and nonspatial learning and memory in adult rats.

The potential facilitative effects of early environmental enrichment and perinatal choline chloride dietary supplementation on male and female adult rats' learning and memory were examined using a "stimulus-elicited investigative," and a social/observational learning-cued spatial memory paradigm. Male and female animals were either maintained in a standard lighted colony (SC) or were given supplementary exposure to a complex environment (EC) for 2 hr daily from 24-90 days of age. In each case, half of the animals were exposed to the choline supplementation both prenatally and postnatally for 24 days. In one paradigm, the 90-day-old EC rats were found to be significantly more responsive than SC rats to each change in the spatial relationships of objects contained in an open field. Neither sex nor early diet of the animals were much of a factor in the investigative behavior observed. In the second paradigm, the effects of the perinatal choline diet did interact with those of sex and postnatal environment to alter the impact of social/observational experience on the acquisition and memory of place in the water maze. The choline-treated EC males were the most influenced by their experience seeing a demonstrator swim to a platform location. The present study provides some further insight into the scope of the long-term functional enhancements produced by perinatal choline supplementation and EC in male and female animals and relates these effects to common modifications to targets of cholinergic basal forebrain systems.

Resequencing of Video using Spatial Indexing

Current work on computer indexing of video is either low level, working with edits and camera motion or high level using a human entered semantic description. In this paper we propose a complementary indexing method, based on the spatial relationships of objects in the video.Spatial reasoning techniques have been applied to pictorial databases, in particular those using two-dimensional (2D) strings as an index representation have been successful. We demonstrate how one 2D string representation may be extended to represent video sequences and how it may be compressed. The presented query scheme makes efficient use of the notation by not requiring the notation to be expanded during matching. Query schemes for both single-frame queries and full subsequence queries are presented. The major improvement is that the query process is not based on the expansion to and evaluation of a sequence of 2D strings, rather the spatial relationship changes may be read directly from the edit sequence. This allows us to easily discard edits which do not affect the objects in the query, greatly reducing the processing required during querying.The use of this retrieval scheme is explored in a simple video interpretation application, that of a guide system. We present a system which sequences video clips from a database to illustrate paths between locations. The retrieval of clips is performed using the techniques for video sequence matching developed in this paper.

Inverse 3-D graphics: A metaphor for visual perception

There are two key elements in defining the problem of visual perception. The first is that useful information about the world, such as the shape, material, illumination, and spatial relationships of objects, is encrypted in the image. Second, the encryption process, of going from a description of the world to an image, is not in general reversible. Any single source of image information is usually ambiguous about its causes in the scene. Seeing is the process of decoding the image information. 3-D computer graphics simulates the process of encrypting scene information into the image. By creating images from synthetic scenes, we can gain insights into the constraints used by the visual system to decode image information, and we can begin to bridge the gap between the simple images of the laboratory and complex natural scenes. Computer graphics modeling and animation tools provide the means to generate stills and animations that produce strong perceptual interpretations, yet are theoretically indeterminate. I will describe several illusions involving computer renderings and animations that illustrate the constraints human perception uses to solve ambiguity about material, shape, and depth.

Approximate topological relations

In spatial data models for various applications, such as geographical information systems (GISs), the importance of topological relations is widely recognized. Topology makes very general statements about the structure and the relations of spatial objects. A refinement of topology by means of other geometric aspects can help to bend the various models that have been developed for topological relations towards a more effective description of geographic space. The introduction of broad boundaries is a direction to define approximate topological relations between spatial objects. In this paper, approximate topological relations are destined to capture boundary uncertainty, variations over time, proximity measures, and vector-raster representations. Approximate topological relations are structured in conceptual neighborhood graphs that have a twofold interpretation: two neighboring relations are at topological distance 1 in terms of the nine-intersection model and can be obtained, one from the other, by an elementary continuous deformation.

THE APPLICATION OF STEREOSCOPIC VIDEO TO UNDERWATER REMOTELY OPERATED VEHICLES

A stereoscopic video system for use with Underwater Remotely Operated Vehicles (ROVs) has been developed by Curtin University's Centre for Marine Science and Technology. The system provides ROV operators with a fully three-dimensional (stereoscopic) view of the ROVs surroundings. This increased perception of depth offers several advantages to both the piloting of ROVs and also to the operation of an ROV manipulator arm.The stereoscopic video system consists of an underwater stereoscopic video camera which fits on the ROV and a stereoscopic display which is installed in the ship-based ROV control room. The system was developed in close cooperation with Woodside Offshore Petroleum which has used the system on their Triton ROV. Three ROVs are currently operated at Woodside's oil fields on Western Australia's North West Shelf.Field use of the system on the Triton ROV has revealed many advantages of stereoscopic video. One of the areas where advantages are particularly evident is in the operation of the manipulator arm. Operators have reported that it is perceptually easier to perform manipulator tasks. This is because the spatial relationship of objects can be immediately identified, making object placement and alignment easier. The system also provides a better understanding of the work site and a perceived improvement in image quality and therefore improved visibility.

A survey of techniques for simulation of dynamic collision detection and response

When several objects are moved about using computer simulation, there is a chance that these objects will collide with each other, which in turn may result in effecting further change in the movement. The two main issues involved are those of detecting that a collision has occurred and then subsequently depicting a response as an effect of collision. Typically the collision detection is a geometric interference problem that depends on the spatial relationship of objects while collision response is a dynamics problem which involves predicting behavior according to physical laws. In this paper we discuss collision detection and response in general and survey several of the more important solutions proposed and currently in use.

3-D vision technology applied to advanced minimally invasive surgery systems.

Current-generation vision for laparoscopic surgery involves flat two-dimensional display on a video monitor; this approach makes it difficult to accurately place the tip of a surgical instrument in the three-dimensional real space of the patient. The surgeon must rely on motion parallax, monocular cues, and other indirect evidence of depth to judge accurately the correct spatial relationship of objects in the field of view. Stereoscopic video can return accuracy to the surgeon. Critical elements in creating stereovision are the biophysical laws governing field of view, focal point, depth of field, accommodation, and convergence. In addition, engineering constraints must be followed, such as fitting a 10-mm port, which are compatible with current systems and economic feasibility. There are two methods for 3-D vision under development which are variations on the same theme of modifying standard laparoscopes by using lenses, mirrors and prisms, and optical shuttering. One method uses two video cameras to simultaneous capture two separate images from a paired optical system. Each image is alternately transmitted to the video monitor (field sequential video) and viewed with electronic or polarizing glasses for a 3-D image. Another method uses a standard laparoscope, optically splits this one image into alternating right/left images, and reconstructs the image as above. A major challenge for both systems is that the distance between the optical elements in the laparoscope is not greater than 10 mm apart and fixed, whereas the human interpupillary distance is greater than 650 mm and can accommodate.(ABSTRACT TRUNCATED AT 250 WORDS)

A three-dimensional iconic environment for image database querying

Retrieval by contents of images from pictorial databases can be effectively performed through visual icon-based systems. In these systems, the representation of pictures with 2D strings, which are derived from symbolic projections, provides an efficient and natural way to construct iconic indexes for pictures and is also an ideal representation for the visual query. With this approach, retrieval is reduced to matching two symbolic strings. However, using 2D-string representations, spatial relationships between the objects represented in the image might not be exactly specified. Ambiguities arise for the retrieval of images of 3D scenes. In order to allow the unambiguous description of object spatial relationships, in this paper, following the symbolic projections approach, images are referred to by considering spatial relationships in the 3D imaged scene. A representation language is introduced that expresses positional and directional relationships between objects in three dimensions, still preserving object spatial extensions after projections. Iconic retrieval from pictorial databases with 3D interfaces is discussed and motivated. A system for querying by example with 3D icons, which supports this language, is also presented. >

Is movement perception color blind?

Our visual environment is usually full of motion. Unquestionably, the perception of movements and spatial relationships of objects is of considerable biological importance. Motion information is also important for decomposing the retinal image into discrete objects (Egure-ground separation), and for the recovety of their three-dimensional shapes (structure from motion). Furthermore, gaze-holding eye movements that compensate for the organism’s own motion or for motion of the observed object rely greatly on visual motion signals. It is hardly surprising, therefore, that biological visual systems have speciakzecl, directionally sensitive motion-detecting neurons. In primates, several cortical areas seem ro be largely devoted to visual motion analysis. We now know from both psychophysical and physiological experiments that motion perception is not merely a convolution of our spatial and temporal perception but represents a fundamental visual dimension as do color or stereoscopic vision 111. Unlike color and stereoscopic vision, however, the capacity to perceive motion appears very early phylogenetically and is found in all animals, including those that lack color or bmocular vision.

Latent learning in a swimming pool place task by rats: evidence for the use of associative and not cognitive mapping processes.

Using a latent learning paradigm, the experiments examine two hypotheses of how rats solve place navigation tasks. According to associative theory, experience with all relevant cues is required for accurate navigation. According to cognitive mapping theory, animals can generate novel trajectories from knowledge of spatial relations of objects in the environment. Rats that had been placed on a platform, which was submerged in a pool of opaque water and was moved each day, were tested later for their ability to find the platform using only surrounding room cues. One 30-sec exposure to a platform location was effective in improving performance. Improvement was greatest when tests were given within minutes of placement, but facilitation was obtained for as long as 4 hr. Improved performance was obtained as soon as rats acquired the procedural aspects of the task but did not increase with subsequent practice. Improved performance was also obtained when pre-trained rats were tested in a novel environment. Despite the advantage conferred by exposure to the target platform, test swims were not accurate, placement-induced improvement was not as great as that following a single swimming trial, and placement combined with a swim resulted in best performance. The results suggest that rats use associative learning processes rather than cognitive mapping to solve place problems in a swimming pool.

QPF A versatile query language for a knowledge-based geographical information system

Abstract This paper presents a query language, QPF, and describes its implementation in a knowledge-based geographical information system (KGIS). Using QPF, users can retrieve both symbolic and graphical data, and browse through the entire database without prior knowledge of the contents and organization of the KGIS. Processing of complex queries, such as query by object spatial relations, is guided by knowledge represented in frames that simplifies not only query processing, but also query definition and makes querying user-friendly.