An analytical study on image databases

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997.Includes bibliographical references (leaves 87-88).by Francine Ming Fang.M.Eng

Terrain Representation And Reasoning In Computer Generated Forces : A Survey Of Computer Generated Forces Systems And How They Represent And Reason About Terrain

Report on a survey of computer systems used to produce realistic or intelligent behavior by autonomous entities in simulation systems. In particular, it is concerned with the data structures used by computer generated forces systems to represent terrain and the algorithmic approaches used by those systems to reason about terrain

Use of Colour in Machine Vision: Colour Representation, Edge Detection with Colour, Segmentation of Colour Space and Colour Constancy

This report is a study of the role of colour and its use in machine vision. Intuitively, for low level image processing, colour provides greater discrimination than grey level for separating different homogenous regions in an image. The first part describes the use of colour in edge detection. In current vision systems, extracting object features such as lines and arcs relies on edge detection. The use of colour images (RGB) can offer additional confidence in the existence of an edge element in one plane when it is corroborated by pixels at the location on one or more of the other planes. The second part investigates the problems and techniques associated with colour image segmentation. A spectral segmentation algorithm based on locating the boundaries of each colour cluster in the spectral space is proposed. The third part investigates the use of colour features for object recognition. Colour information also provides a useful cue for object localisation and identification. The major issues that have to be addressed are colour constancy and representation, and also, their connections to segmentation. Finally, a system for locating object surfaces based on a simplified colour constancy and its colour representation is proposed

Vision-assisted modeling for model-based video representations

Thesis (Ph. D.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1997.Includes bibliographical references (leaves 134-145).by Shawn C. Becker.Ph.D

First CLIPS Conference Proceedings, volume 2

The topics of volume 2 of First CLIPS Conference are associated with following applications: quality control; intelligent data bases and networks; Space Station Freedom; Space Shuttle and satellite; user interface; artificial neural systems and fuzzy logic; parallel and distributed processing; enchancements to CLIPS; aerospace; simulation and defense; advisory systems and tutors; and intelligent control

Spatial coincidence modelling, automated database updating and data consistency in vector GIS

This thesis presents formal approaches for automated database updating and consistency control in vector- structured spatial databases. To serve as a framework, a conceptual data model is formalized for the representation of geo-data from multiple map layers in which a map layer denotes a set of terrain objects of the same mapping context, e.g., cadastral, soil mapping, etc. The necessity for a generalised model arises from the frequent requirement in spatial analysis and planning for a geometric integration of several different views of the world, whereas most existing data models were designed from the perspective of a "single application" leading to ad hoc and repeated overlay computations (during query processing) when dealing with an integrated analysis. An alternative model is therefore proposed in this thesis for the geometric integration of geo-data from multiple map layers. The proposed model is an object-based, query-oriented 2.5D data model for multi-valued vector maps (DMMVM).A multi-valued vector map refers to the vector-based representation of terrain objects from multiple map layers whereby two objects of the same geometric type may be spatially coincident. Two objects of the same type are spatially coincident if they (partially) overlap in space. In this model, positions of objects are defined in a 3D metric space but embedded in 2D topologic space. The model is based on the 2D formal data structure (FDS) for singlevalued vector maps.Terrain objects play a central role in the terrain description; each object has a thematic component and a geometric component. In the thematic domain, the objects can be grouped into thematic classes in which each class has a specific attribute structure, and in the geometric domain the object types (points, lines and areas) are distinguished for a 2D or 2.5D terrain description.A geometric data type -- the m-dimensional container, or simply m-container, where m ε{0,1,2} -- is then introduced to model spatial coincidence among objects of the same geometric type. By introducing the container data type, overlapping sections across the layers are uniquely identified such that they have their own individual geometric data and nonspatial data, apart from those inherited from the overlapping objects; they can then be maintained and manipulated by the DBMS just like single objects. Using graph theory as a mathematical tool, the three container types are then represented by the topologic primitives arc and node. A node defines one 0-container andlor the beginning or end of an arc, while an arc defines (part of) one 1-container andlor (part of) the boundary of a 2-container. The arc is defined by one start node and one end node, and a node is defined by a coordinate triplet X,Y,Z. A flexible integration of the model with a DTM is also presented in the thesis, using an edge-based TIN. Two primitives of the edge-based TIN (edge and vertex) are added to the data types of the DMMVM to define the integrated model.Research and development on the updating of geo-information have been confined mainly to the aspects of data collection and change detection, with little emphasis on the corresponding automated propagation of the updating in the database in a consistent manner. To address the latter aspect, procedures are formulated in the thesis for a consistent automated updating of a vector-structured database, using the DMMVM as a framework. Algorithms are provided for the automated update propagation such that topology is automatically updated by the system, while maintaining structural and semantic consistency. This will improve on the current practice in operational systems, which usually requires a delayed reconstruction of topology whenever there is a geometric change in the database. Algorithms are developed for the insertion, deletion or modification of each of the eight data types (area, line, point, 2- container, 1-container, 0-container, arc and node) in the DMMVM. The human operator interacts with the system at the object-level, while the system propagates the update. The topology of the database is updated dynamically by the system by evaluating, using computational geometry, the topologic relationship between the new primitive (are or node) of an object and the existing primitives in the database. The type of relationship detected will then activate the relevant consistency rule (including update propagation) to validate the topology and consistency of the database. The system alerts the human operator if it is not possible for it to resolve the inconsistency.To enforce data consistency during geometric updating of the database, consistency rules are defined to ensure structural consistency, while a monitoring strategy is formulated for semantic (application-dependent, topologic) constraints. In both cases, topology plays the central role as an "alerter" of constraint violations. Thus the possible topologic relationships among the three elementary object types (area, line and point), and among the geometric primitives (arc and node) in the DMMVM are formalised and algorithms are defined for detecting the occurrence of any of the elementary relationships for any object combination. Then the consistency constraints can be translated to topologic relationships and stored in the database as events, and the corresponding responses of the system to enforce consistency can be defined as actions, thus giving a rule-based procedure (using the if event then action convention) for the management of data consistency in spatial databases.The DMMVM was translated into a relational database structure and an object-oriented database structure to facilitate implementation in a variety of systems. The object-oriented data structure and the consistency rules and algorithms were tested experimentally using Postgres, an extended relational database management system. Data were acquired using the Kork digital mapping system, on a Planicomp C120 photogrammetric stereoplotter equipped with a Zeiss Videomap and a Calcomp drawing board digitizer.The thesis concludes with an evaluation of the proposed model and an outline of areas requiring further investigations