Line generalisation by repeated elimination of points

Visvalingam, M.; Whyatt, J. Duncan

doi:10.1179/000870493786962263

Cited by 132 publications

(81 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 'hand-drawn' or 'sketchy' effect on the polygons has been achieved by a combination of polygon smoothing, line smoothing, multiple-overlay and image composite operations in order to give the impression that they have been drawn using felt-tip pens (akin to the approach first suggested by Ashton, 2012). Conversely, the line features were simplified using the Visvalingam-Whyatt line generalisation algorithm (Visvalingam and Whyatt, 1993), and overlaid using transparency and image composite operations in order to give the appearance of having been drawn using highlighter pens. The main difference with this approach is that the level of abstraction varies from feature to feature as opposed to being uniform across the dataset as is the case in the grid-based approaches, which may prove more disorientating for users.…”

Section: Encourage Players To Navigate 'Head-up' Rather Than 'Head-domentioning

confidence: 99%

Mapping the Beach Beneath the Street: Digital Cartography for the Playable City

Coulton

Huck

Gradinar

et al. 2016

Gaming Media and Social Effects

View full text Add to dashboard Cite

-Maps are an important component within many of the playful and gameful experiences designed to turn cities into a playable infrastructures. They take advantage of the fact that the technology used for obtaining accurate spatial information, such as GPS receivers and magnetometers (digital compasses), are now so widespread that they are considered as 'standard' sensors on mobile phones, which are themselves ubiquitous. Interactive digital maps, therefore, are are widely used by the general public for a variety of purposes. However, despite the rich design history of cartography digital maps typically exhibit a dominant aesthetic that has been designed to serve the usability and utility requirements of turn-by-turn urban navigation, which is itself driven by the proliferation of in-car and personal navigation services. The navigation aesthetic is now widespread across almost all spatial applications, even where a bespoke cartographic product would be better suited. In this chapter we seek to challenge this by exploring novel neo-cartographic approaches to making maps for use within playful and gameful experiences designed for the cities. We will examine the potential of design approaches that can producte not only more aesthetically pleasing maps, but also offer the potential for influencing user behaviour, which can be used to promote emotional engagement and exploration in playable city experiences.

show abstract

Section: Encourage Players To Navigate 'Head-up' Rather Than 'Head-domentioning

confidence: 99%

Mapping the Beach Beneath the Street: Digital Cartography for the Playable City

Coulton

Huck

Gradinar

et al. 2016

Gaming Media and Social Effects

View full text Add to dashboard Cite

show abstract

“…Note that the distance along a coastline will depend on the precision of the coastline representation, with higher precisions generating longer distances. There were 74032 vertices in the constructed shape map, so a global simplification algorithm [35] was used to simplify the map down to a 500 vertex coastline map (Figure 3). The coastline is represented by a straight line segment drawn between each pair of vertices.…”

Section: Generation Of Daily Cloudinessmentioning

confidence: 99%

A method for generating synthetic hourly solar radiation data for any location in the south west of Western Australia, in a world wide web page

2014

View full text Add to dashboard Cite

An algorithm was developed to generate synthetic hourly cloudiness data for any time of the year at any location in the south west region of Western Australia (WA). To enable the algorithm to be used for simulation of the power output of both tilted photovoltaic and concentrating solar power systems, a metric of cloudiness was defined which modifies the clear sky beam, diffuse and reflected solar transmittance. Seasonally and positionally adjusted values of daily cloudiness were generated by roughly mimicking the geographic pattern of annual rainfall in WA. Rather than longitude and latitude, distance along the coastline and distance inland from the coast were used as the positional coordinates. Hourly cloudiness data was generated from the daily values using a first order autoregression algorithm with time varying mean and standard deviation. Two years of measured hourly horizontal solar irradiance data from a network of 31 weather stations was used to calibrate the algorithm. The algorithm was simple enough to run inside a world wide web page and has the potential to be adapted to other regions with a similar pattern of declining inland rainfall.

show abstract

“…A number of polygon simplification algorithms have been developed in digital cartography for map generalization [5], such as the Douglas-Peucker algorithm [6], the Visvalingam-Whyatt algorithm [7], and the bend-simplify algorithm [8]. None of these algorithms, however, satisfies one critical requirement for mappings used in LBS applications: the simplified polygon should be fully enclosed in the original polygon so that the simplified polygon should never produce false positives.…”

Section: Introductionmentioning

confidence: 99%

Polygon Simplification for Location-Based Services Using Population Density

Song

Lee

Schulzrinne

2011

2011 IEEE International Conference on Communications (ICC)

View full text Add to dashboard Cite

Abstract-An important group of location-based services (LBS), including 9-1-1 service, rely on the mapping between a user's location and a service boundary in order to select the appropriate service provider. In such cases, mobile clients can cache the mapping information to reduce service latency and server load. However, caching such a mapping can be burdensome on mobile devices because representing the polygon that defines a service boundary requires a large amount of data.We present GeoPS-PD, a polygon simplification algorithm designed for LBS applications. Unlike existing algorithms, GeoPS-PD never produces a false positive, is tunable at runtime for the desired balance between target polygon size and area coverage, and optionally takes into account the population density. We demonstrate the efficacy of GeoPS-PD using the US state boundary data. For New York, GeoPS-PD produces a simplified polygon which is only 3% of the original size, yet covers 95% of the original area, and makes the LBS queries 3.17 times faster.

show abstract

Line generalisation by repeated elimination of points

Cited by 132 publications

References 7 publications

Mapping the Beach Beneath the Street: Digital Cartography for the Playable City

Mapping the Beach Beneath the Street: Digital Cartography for the Playable City

A method for generating synthetic hourly solar radiation data for any location in the south west of Western Australia, in a world wide web page

Polygon Simplification for Location-Based Services Using Population Density

Contact Info

Product

Resources

About