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R. D. Merrill

Bio: R. D. Merrill is an academic researcher. The author has contributed to research in topics: Intersection & Point (geometry). The author has an hindex of 1, co-authored 2 publications receiving 109 citations.

Papers
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Journal ArticleDOI
TL;DR: A novel computer-searchable representation for the three basic pictorial features, contour maps, region coverage, and line structures, is described, which provides a rapid means of searching large files for data associated with geometric position as well as with attribute value.
Abstract: A novel computer-searchable representation for the three basic pictorial features, contour maps, region coverage, and line structures, is described. The representation, which has practical storage requirements, provides a rapid means of searching large files for data associated with geometric position as well as with attribute value. An application of this representation to handling terrain information illustrates its utility. The algebraic properties of the data structure make it computationally easy to determine whether a point lies within a closed boundary; compute the area contained by a closed boundary; generate the closed boundary representing the union or intersection of two closed boundaries; and determine the neighboring boundaries to a point and the minimum distances between them and the point.

108 citations

Journal ArticleDOI
TL;DR: In this paper, a novel computer-searchable representation for the three basic pictorial features, contour maps, region coverage, and line structures, is described, which has practical storage requirements and provides a rapid means of searching large files for data associated with geometric position as well as with attribute value.
Abstract: A novel computer-searchable representation for the three basic pictorial features, contour maps, region coverage, and line structures, is described. The representation, which has practical storage requirements, provides a rapid means of searching large files for data associated with geometric position as well as with attribute value. An application of this representation to handling terrain information illustrates its utility. The algebraic properties of the data structure make it computationally easy to determine whether a point lies within a closed boundary; compute the area contained by a closed boundary; generate the closed boundary representing the union or intersection of two closed boundaries; and determine the neighboring boundaries to a point and the minimum distances between them and the point.

1 citations


Cited by
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Journal ArticleDOI
TL;DR: L'accentuation est mise sur la representation de donnees dans les applications de traitement d'images, d'infographie, les systemes d'informations geographiques and the robotique.
Abstract: Apercu sur les quadarbres et les structures de donnees hierarchiques. Elles sont basees sur le principe de decomposition recursive. L'accentuation est mise sur la representation de donnees dans les applications de traitement d'images, d'infographie, les systemes d'informations geographiques et la robotique. On examine en detail un certain nombre d'operations dans lesquelles de telles structures de donnees trouvent leur utilisation

2,273 citations

Journal ArticleDOI
TL;DR: Various forms of line drawing representation are described, different schemes of quantization are compared, and the manner in which a line drawing can be extracted from a tracing or a photographic image is reviewed.
Abstract: This paper describes various forms of line drawing representation, compares different schemes of quantization, and reviews the manner in which a line drawing can be extracted from a tracing or a photographic image. The subjective aspects of a line drawing are examined. Different encoding schemes are compared, with emphasis on the so-called chain code which is convenient for highly irregular line drawings. The properties of chain-coded line drawings are derived, and algorithms are developed for analyzing line drawings to determine various geometric features. Procedures are described for rotating, expanding, and smoothing line structures, and for establishing the degree of similarity between two contours by a correlation technique. Three applications are described in detail: automatic assembly of jigsaw puzzles, map matching, and optimum two-dimensional template layout

1,485 citations

Journal ArticleDOI
01 Jul 1992
TL;DR: Both template matching and structure analysis approaches to R&D are considered and it is noted that the two approaches are coming closer and tending to merge.
Abstract: Research and development of OCR systems are considered from a historical point of view. The historical development of commercial systems is included. Both template matching and structure analysis approaches to R&D are considered. It is noted that the two approaches are coming closer and tending to merge. Commercial products are divided into three generations, for each of which some representative OCR systems are chosen and described in some detail. Some comments are made on recent techniques applied to OCR, such as expert systems and neural networks, and some open problems are indicated. The authors' views and hopes regarding future trends are presented. >

892 citations

Journal ArticleDOI
TL;DR: A regular decomposition of picture area into successively smaller quadrants is defined, which involves logarithmic search, and the resulting picture representation is shown to enable rapid access of image data without regard to position, efficient storage, and approximate structural descriptions of constituent patterns.

290 citations

Journal ArticleDOI
TL;DR: This framework is used to provide clarification of how varying data models, as well as their inherent advantages and disadvantages, are interrelated, and provides an insight into how these conflicting demands may be balanced in a more systematic and predictable manner for practical applications.
Abstract: This paper examines the major types of spatial data models currently known and places these models in a comprehensive framework. This framework is used to provide clarification of how varying data models, as well as their inherent advantages and disadvantages, are interrelated. It also provides an insight into how these conflicting demands may be balanced in a more systematic and predictable manner for practical applications, and reveals directions for needed future research. On examine les principaux types de modeles de donnees spatiales actuels, et on les place dans un cadre global. Ce cadre est utilise pour eclaircir comment ces divers modeles spatiaux, de meme que leurs avantages et desavantages, sont interrelies. Le cadre laisse aussi voir comment ces demandes contradictoires peuvent etre equilibrees d'une facon plus systematique et previsible pour des applications pratiques, et revele les directions que doit prendre la recherche future.

268 citations