Towards sketch-based exploration of terrain : a feasibility study

Lesage, P. L.; Visvalingam, M.

Abstract

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 (Visvalingam, 1999a). As Gestalt psychologists have shown, the perceptual system is adept at organising sparse cues into potentially meaningful forms
(Hochberg, 1964). This is especially so when images are animated. An often -used illustration is that of the spontaneous recognition of a Dalmatian dog emerging from frames of scattered spots when they are animated. However, demonstrations such as this and other animated sketches on TV are often contrived to succeed. Northrup and Markosian (2000) noted how the lack of inter-frame coherence in real time animation of silhouettes could be distracting. In scientific
applications, there is also a need to abstract other form defining cues from a grid Digital Elevation Model (DEM), also known as a height field. Dawson (1994) and Visval ingam and Dawson (1998)
found that it was possible to extract static 20 sketches us i ng Visvalingam's algorithm (reported in Visvalingam and Whyatt, 1993); Figure 1 provides an example of their P-stroke sketch.
However, Visvalingam and Dowson (2000) found that similar sketches, based on the Ramer (1972)/Douglas-Peucker (1973) algorithm, were not as successful. The graphical primitives were
misplaced and did not bond too well into a coherent sketch. Even where the marks cohered into an easily perceived sketch, the outcome was misleading. Disciplines concerned with other forms
of abstraction, such as statistics (Moroney, 1951) and cartography (Monmonier, 1991), are well aware of the scope for unintentional distortion.

Citation

Lesage, P. L., & Visvalingam, M. Towards sketch-based exploration of terrain : a feasibility study

• Working Paper Type: Discussion Paper
• Deposit Date: Mar 11, 2014
• Journal: Lesage, P-L. and Visvalingam, M. “Towards sketch-based exploration of terrain”, Computers and Graphics
• Pages: 30
• Series Title: C.S.I.R.G. Discussion Papers (University of Hull Cartographic Information Systems Research Group)
• Series Number: 19
• Book Title: Towards sketch-based exploration of terrain : a feasibility study
• Keywords: Cartography -- Data processing; Computer science
• Public URL: https://hull-repository.worktribe.com/output/459369