Toward web mapping with vector data

Journal of the Brazilian Computer Society, 2009

With the increasing popularity of web-based map browsers, remotely obtaining a high quality depiction of cartographic information has become commonplace. Most web mapping systems, however, rely on high-capacity servers transmitting pre-rendered tiled maps in raster format. That approach is capable of producing good quality renderings on the client side while using limited bandwidth and exploiting the browser's image cache. These goals are harder to achieve for maps in vector format. In this work, we present an alternative client-server architecture capable of progressively transmitting vector maps in levels-of-detail (LOD) by using techniques such as polygonal line simplification, spatial data structures and, most importantly, a customized memory management algorithm. A multiplatform implementation of this system is described, where the client application is written entirely in JavaScript and processed within the web browser, avoiding the need of external applications or plug-ins. Results of experiments aimed at gauging both the performance and the display quality obtained with the system are presented and explained. Extensions to the system are also discussed, including issues such as level-of-detail versus visual importance tradeoffs and the handling of closed polygonal lines.

Proceedings of the I …, 1999

The use of Geographic Information Systems in the web requires the transmission of maps as figures. These figures can only be encoded as raster images if a very low resolution is used, otherwise they produce very large files. An important feature of these figures is that they usually have polygonal lines with a great number of points. General-purpose vector formats generate files which are also too large to be transmitted through the web. TWF is an active and scalable vector file format that is capable of storing these map figures in small files. This paper presents a set of software components that constitute a simple framework to support map visualization over the web based on this format. Examples are shown to evaluate the proposed strategies and conclusions are drawn based on these examples.

2001

Within distributed computing environments, access to very large geospatial datasets often suffers from slow or unreliable network connections. To allow users to start working with a partially delivered dataset, progressive transmission methods are a viable solution.

Lecture Notes in Geoinformation and Cartography, 2007

The most widespread Open Geospatial Consortium (OGC) specification for GIS defines the interface of a Web Map Service (WMS). A service implementing this interface accepts an HTTP request from a client and replies with a map encoded in either a raster format or a vector format such as SVG (Scalable Vector Graphics). However, in both cases, the response of the WMS represents a static map that cannot react to user actions. It would be useful to obtain vector maps encoded in active SVG that can execute actions and change their visual appearance in response to usertriggered events. In this paper, we present the specification of an Active Web Map Service (AWMS), which is defined as an extension of the OGC WMS specification that allows the retrieval of active SVG maps. Given that a WMS uses the OGC SLD language (Styled Layer Descriptor) to describe the set of layers and visualization styles available, our AWMS specification also needs an extension of such specification to describe the active component of the maps. This is achieved by adding a new type of SLD element called Active Symbolizer that enables the definition of active and dynamic behaviour for the geographic objects that belong to each geographic information layer.

Journal of Geographic Information System, 2014

There is a growing need for web-based geographic information systems for easy and fast dissemination, sharing, displaying and processing of spatial information. The tremendous growth in the use of web and open-source geospatial resources has sparked development of web-based spatial applications to address multidisciplinary issues with spatial dimensions. This paper presents the integration of open-source geospatial tools and web technology to visualize and interact with spatial data using web browser. The goal of this paper is to implement a prototype system for web-based mapping by providing step-by-step instructions in order to encourage the eager developers and interested readers to publish their maps on the web with no prior technical experience in map servers. The implementation of mapping prototype shows the utilization of open-source geospatial tools which results in a rapid implementation with minimal or no software input cost.

ISPRS International Journal of Geo-Information

Web mapping and the use of geospatial information online have evolved rapidly over the past few decades. Almost everyone in the world uses mapping information, whether or not one realizes it. Almost every mobile phone now has location services and every event and object on the earth has a location. The use of this geospatial location data has expanded rapidly, thanks to the development of the Internet. Huge volumes of geospatial data are available and daily being captured online, and are used in web applications and maps for viewing, analysis, modeling and simulation. This paper reviews the developments of web mapping from the first static online map images to the current highly interactive, multi-sourced web mapping services that have been increasingly moved to cloud computing platforms. The whole environment of web mapping captures the integration and interaction between three components found online, namely, geospatial information, people and functionality. In this paper, the trends and interactions among these components are identified and reviewed in relation to the technology developments. The review then concludes by exploring some of the opportunities and directions.

AGILE: GIScience Series

Accessing geospatial data via the internet is a common way for data integration. This web mapping approach often relies on web services like the web map tile service (WMTS) for accessing maps or the web feature service (WFS) for accessing vector data. An alternative way, which combines aspects like the higher performance through tiling and the usage of vector data is the usage of tiled vector data. This short paper describes an approach for the creation of tiled vector data using standard PostgreSQL, with spatial extension PostGIS, functionality. For that, custom PostGIS functions are implemented to select relevant vector data out of the PostgreSQL database, dynamically generalize/simplify geometries and transform the data to Mapbox mvt format. This approach of creating tiled vector data shall be used for further implementations of web maps for building more efficient spatial data infrastructures.

Journal of Geographical Systems, 2004

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2011

In this paper we evaluate the potential of the next major revision of HTML (Hypertext Markup Language), that is HTML5, to provide an effective platform for the transmission and visualization of vector based geographical data. Relative to the current version of HTML, HTML 4.01, HTML5 offers an improved platform to perform these tasks through greater interoperability with existing technologies and the introduction of many new API's. Visualization of vector data can be achieved using the new methods of inline-SVG and the Canvas API. An analysis of the pros and cons of each method is presented. HTML5 introduces a novel WebSocket API which defines a full-duplex communication channel between client and server. This provides improved data communication both in terms of bandwidth utilization and network latency relative to existing push technologies. To demonstrate the effectiveness of HTML5 for vector data delivery a novel selective progressive transmission methodology is implemented using the WebSocket and Canvas API's.

Transactions in GIS. 2019;00:1-13. | 1 wileyonlinelibrary.com/journal/tgis 1 | INTRODUC TI ON Rapid development of technology in recent decades has not only introduced new possibilities in GIS and cartog-raphy, but also transformed them. The main focus has shifted from traditional mapping and analysis of spatial data to new, digitally better-supported approaches. For example, experts can now produce three-dimensional models from digital images, have to deal with different types of big data, and are finding ways to apply machine learning to Abstract Companies and individual developers have recently put serious effort into improving web mapping libraries. A significant front in this development is hardware-accelerated vector graphics. Owing to those efforts, and the continuously evolving World Wide Web, users can visualize large vector layers, and even animate them. On the other hand, this rapid development cannot be observed with raster data. There are some data abstraction libraries for reading raster files, although web mapping libraries do not use them to offer raster capabilities. Since there are no mature ras-ter management pipelines on the web, this study explores two inherently different techniques for handling raster data. One of them uses the traditional, texture-based method. The other is a hybrid technique rendering raster layers as vectors, overcoming some limitations of the raster model. While the traditional technique gives a smooth user experience , the hybrid method shows promising results for rendering hexagonal coverages.