All Outputs (19)

The Visvalingam algorithm: metrics, measures and heuristics (2015)
Preprint / Working Paper
Visvalingam, M. The Visvalingam algorithm: metrics, measures and heuristics

This paper provides the background necessary for a clear understanding of forthcoming papers relating to the Visvalingam algorithm for line generalisation, for example on the testing and usage of its implementations. It distinguishes the algorithm fr... Read More about The Visvalingam algorithm: metrics, measures and heuristics.

Towards sketch-based exploration of terrain : a feasibility study (2000)
Preprint / Working Paper
Lesage, P. L., & Visvalingam, M. Towards sketch-based exploration of terrain : a feasibility study

First paragraph:
The Cartographic Information Systems Research Group (CISRG) of the University of Hull is keen to revive interest in the dying art of landscape sketching and re-stage it on today's reactive and
dynamic computer technology (Visvaling... Read More about Towards sketch-based exploration of terrain : a feasibility study.

Cognitive evaluation of computer-drawn sketches (1999)
Preprint / Working Paper
Visvalingam, M., & Dowson, K. Cognitive evaluation of computer-drawn sketches

First paragraph:
Global terrain data is becoming increasingly available in various forms, such as contours, Triangulated Irregular Networks (TINs) and grid Digital Elevation Models (DEMs) . DEMs are also known as height
fields and as altitude matri... Read More about Cognitive evaluation of computer-drawn sketches.

Sources of variability in cartographers' deconstruction of fractals : paper presented at the 18 November 1998 meeting of the British Cartographic Society's Design Group at the University of Glasgow (1998)
Preprint / Working Paper
Visvalingam, M. Sources of variability in cartographers' deconstruction of fractals : paper presented at the 18 November 1998 meeting of the British Cartographic Society's Design Group at the University of Glasgow

Opening paragraph:
This research was designed for two reasons: firstly, to involve anyone with an interest in cartographic visualisation to participate in eliciting cartographic knowledge and to provide them with the opportunity to contribute their... Read More about Sources of variability in cartographers' deconstruction of fractals : paper presented at the 18 November 1998 meeting of the British Cartographic Society's Design Group at the University of Glasgow.

A computer science perspective on the bendsimplication algorithm (1998)
Preprint / Working Paper
Visvalingam, M., & Herbert, S. P. A computer science perspective on the bendsimplication algorithm

Algorithms for sketching surfaces (1997)
Preprint / Working Paper
Visvalingam, M., & Dowson, K. Algorithms for sketching surfaces

First paragraph:
Until relatively recently, mainstream computer graphics has focused mainly on the challenge of simulating photorealism. Now that this aim has been realised to a large extent, a growing band of researchers (Sasada, 1987; Dooley and C... Read More about Algorithms for sketching surfaces.

Approximation, generalisation and deconstruction of planar curves (1996)
Preprint / Working Paper
Visvalingam, M. Approximation, generalisation and deconstruction of planar curves

Generalising roads on large-scale maps : a comparison of two algorithms (1994)
Preprint / Working Paper
Visvalingam, M., & Williamson, P. J. Generalising roads on large-scale maps : a comparison of two algorithms

This paper reports the results of an in-depth study which investigated two algorithms for line simplification and caricatural generalisation, namely those developed by Douglas and Peucker, and Visvalingam respectively. The use of large-scale data for... Read More about Generalising roads on large-scale maps : a comparison of two algorithms.

Global dimensions for the recognition of prototypical urban roads in large-scale vector topographic maps (1993)
Preprint / Working Paper
Visvalingam, M., Varley, D., & Wright, C. P. Global dimensions for the recognition of prototypical urban roads in large-scale vector topographic maps

This paper outlines a simple strategy for recognising prototypical cases of urban roads given only their geometric forms. Two new indicators, namely exits and occupancy, are used together with average width to label regions as roads. Even in its pres... Read More about Global dimensions for the recognition of prototypical urban roads in large-scale vector topographic maps.

Line generalisation by repeated elimination of the smallest area (1992)
Preprint / Working Paper
Visvalingam, M., & Whyatt, J. D. Line generalisation by repeated elimination of the smallest area

This paper presents a new approach to line generalisation which uses the concept of "effective area " for progressive simplification of a line by point elimination. Two coastlines are used to compare the performance of this, with that of the widely u... Read More about Line generalisation by repeated elimination of the smallest area.

Visualisation, VISC and scientific insight (1991)
Preprint / Working Paper
Visvalingam, M. Visualisation, VISC and scientific insight

First paragraph:
The report by McCormick et al (1987) on Visualisation in Scientific Computing (ViSC) played a major role in drawing attention to the increasing need and scope for visual computing. There is no doubt that developments in computer-bas... Read More about Visualisation, VISC and scientific insight.

Cartographic algorithms : problems of implementation and evaluation and the impact of digitising errors (1990)
Preprint / Working Paper
Visvalingam, M., & Whyatt, J. D. Cartographic algorithms : problems of implementation and evaluation and the impact of digitising errors

Cartographic generalisation remains one of the outstanding challenges in digital cartography and Geographical Information Systems (GIS). It is generally assumed that computerisation will lead to the removal of spurious variability introduced by the s... Read More about Cartographic algorithms : problems of implementation and evaluation and the impact of digitising errors.

Trends and concerns in digital cartography (1989)
Preprint / Working Paper
Visvalingam, M. Trends and concerns in digital cartography

Digital cartography is the technology concerned with the
construction and use of computer-based systems for the practice of
cartography and its applications. This paper starts with a brief
introduction to cartography and cartographic maps. It then... Read More about Trends and concerns in digital cartography.

The Douglas-Peucker algorithm for line simplification : re-evaluation through visualisation (1989)
Preprint / Working Paper
Visvalingam, M., & Whyatt, J. D. The Douglas-Peucker algorithm for line simplification : re-evaluation through visualisation

The primary aim of this paper is to illustrate the value of
visualization in cartography and to indicate that tools for the
generation and manipulation of realistic images are of limited value
within this application. This paper demonstrates the v... Read More about The Douglas-Peucker algorithm for line simplification : re-evaluation through visualisation.

Management of digital map data using a relational database model (1989)
Preprint / Working Paper
Visvalingam, M., & Sekouris, N. M. Management of digital map data using a relational database model

This end-of - grant report formally concludes the OS/CISRG
collaboration on the one year project entitled "Management of Digital
Map Data Using a Relational Database Model". This introductory
section provides the background to the project, an over... Read More about Management of digital map data using a relational database model.

Cartography, geographical information systems and maps in perspective (1988)
Preprint / Working Paper
Visvalingam, M. Cartography, geographical information systems and maps in perspective

From the Introduction:
The aims of this paper are two-fold. The paper seeks to provide
support for the ICA proposition that there is a need to redefine
cartography and maps. It then explores the various issues which may
either provide guidelines... Read More about Cartography, geographical information systems and maps in perspective.

Standardising basic spatial units : problems and prospects (1988)
Preprint / Working Paper
Visvalingam, M. Standardising basic spatial units : problems and prospects

First paragraph:
The choice of Basic Spatial Units (BSUs) is a critical decision in all
spatial information systems, whether manual or computerised. BSUs are the smallest geographic entities for which information is collected and/or made available.... Read More about Standardising basic spatial units : problems and prospects.

Problems in the design and implementation of a GKS-based user interface for a graphical information system (1987)
Preprint / Working Paper
Visvalingam, M. Problems in the design and implementation of a GKS-based user interface for a graphical information system

State-of-the-art Graphical (mainly Geographical)
Information Systems (GIS) began life in the early 1970s and
are now well established on multi-user computer systems.
They support the capture, storage, retrieval, mathematical
manipulation and disp... Read More about Problems in the design and implementation of a GKS-based user interface for a graphical information system.

From line geometry to area topology (1986)
Preprint / Working Paper
Kirby, G. H., Visvalingam, M., & Wade, P. R. From line geometry to area topology

Area objects are represented on a computer by geometric or locational information (which describe the course of their boundaries), topological information (which describe the areal units to which boundaries belong), and geographic or other informatio... Read More about From line geometry to area topology.