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Current Trends in Vector-Based Internet Mapping: A Technical Review

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Possibilities and limitations of Internet cartography software largely depend on the pace set by the software industry. The variety of commercial and non-commercial software caters for the needs of a continuously growing mapping community, including both professional and amateur cartographers. This chapter provides an overview of state-of-the-art technologies for vector-based Web-mapping as of the beginning of 2011. Both proprietary and open format technologies are discussed for vector data rendering in browsers, highlighting their advantages and disadvantages. The discussed technologies are Adobe Flash, Microsoft Silverlight, Scalable Vector Graphics (SVG), JavaFX, Canvas, and WebGL. The chapter also discusses client and server side frameworks which provide Application Programming Interfaces (APIs) for creating custom interactive maps, mainly by overlaying raster images with vector data.
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Chapter 3
Current Trends in Vector-Based Internet
Mapping: A Technical Review
Christophe Lienert, Bernhard Jenny, Olaf Schnabel, and Lorenz Hurni
Abstract Possibilities and limitations of Internet cartography software largely
depend on the pace set by the software industry. The variety of commercial and
non-commercial software caters for the needs of a continuously growing mapping
community, including both professional and amateur cartographers. This chapter
provides an overview of state-of-the-art technologies for vector-based Web-
mapping as of the beginning of 2011. Both proprietary and open format
technologies are discussed for vector data rendering in browsers, highlighting
their advantages and disadvantages. The discussed technologies are Adobe Flash,
Microsoft Silverlight, Scalable Vector Graphics (SVG), JavaFX, Canvas, and
WebGL. The chapter also discusses client and server side frameworks which
provide Application Programming Interfaces (APIs) for creating custom interactive
maps, mainly by overlaying raster images with vector data.
3.1 Introduction
Internet maps are the major form of spatial information delivery, as the Internet is
today the primary medium for the transmission and dissemination of maps
(Peterson 2008). For map authors, the maze of available techniques for creating
and distributing Web maps is overwhelming, while authoring tools for Web-maps
meeting the demands of high-quality cartography are difficult to find. Map authors
may choose between GIS and graphics software products to create maps for the
Internet, but these off-the-shelve maps oftentimes fall short of effectively convey-
ing information. There are three main reasons for this shortcoming: (a) the design of
these maps sometimes does not take into account the specific limitations of digital
displays (Jenny et al., 2008); (b) the maps are often restricted in using standard
C. Lienert (*)
Landscape and Waters, Canton of Aargau, 5001 Aarau, Switzerland
e-mail: christophe.lienert@ag.ch
M.P. Peterson (ed.), Online Maps with APIs and WebServices,
Lecture Notes in Geoinformation and Cartography,
DOI 10.1007/978-3-642-27485-5_3, #Springer-Verlag Berlin Heidelberg 2012
23
functionality provided by the authoring software; and (c) they do not take full
advantage of interactive features available in modern Web-browsers. Not only is
the situation of available products confusing and overwhelming, there are also out-
of-date technologies, which are not developed further. Likewise, some of the new
technologies are characterized by short life cycles: they have disappeared as fast as
they have arrived on the scene.
In comparison to raster-based maps, vector graphics formats offer a series of
advantages for interactive mapping: (a) They are scalable without loss of informa-
tion or graphical artefacts; (b) the symbolization is adjustable on-the-fly (e.g., line
width, transparency, fill color); (c) the geometry and symbolization can be ani-
mated; (d) map features can be shown and hidden without regenerating and
reloading the entire map; (e) attributes can be attached to each individual map
feature; (f) map features, such as diagrams, can be generated on-the-fly; and (g) the
geometry can be changed, allowing for lossless projection to other coordinate
systems (Schnabel and Hurni 2009).
In this chapter, we confine ourselves to the description and assessment of current
technologies for vector-based mapping on the Internet. Raster-based Web-mapping
is not part of this chapter, and only cross-platform and cross-browser technologies
are treated. The chapter refers to the state-of-the-art as of the beginning of 2011 and
the discussed technologies relate to the most current browser versions, i.e., Mozilla
Firefox 4, Internet Explorer 9, Apple Safari 5, Opera 11, and Google Chrome 8.
3.2 Browser Technology for Vector Data Rendering
Vector mapping is based on vector graphics which use geometrical primitives such
as points, lines, curves, or polygons. These primitives, in turn, are all based on
mathematical equations. Base technologies for vector mapping may be defined as
technology, or software, or even entire application programming interfaces (API),
which are capable of creating, editing, and extending such vector-based graphics
for the Web. The graphic objects may be changed by editing the geometry infor-
mation and the graphical attributes. Affine transformation operators allow for
stretching, twisting, and rotating the objects.
The most current and established vector technologies for the Web are presented
in this section. Both the associated authoring tools and the way vector content is
provided to the user are discussed. A distinction in proprietary and open-source
software is made since considerable differences exist as to business and develop-
ment models. An open-source approach allows for the extraction and further
modification of vector graphics objects, or even for the technical advancement of
authoring and rendering software. Proprietary source code, in contrast, is mostly
delivered in a compiled binary form and is therefore non human-readable. Table 3.1
shows an overview of base technologies for vector mapping.
Java Applets and Vector Markup Language (VML) technology are not discussed
in this article. Due to their complex programming environment, Java Applets are
24 C. Lienert et al.
comparatively little used to produce vector-based maps (Byrne et al., 2010).
JavaFX is a modern alternative for the Java environment providing similar graphi-
cal capabilities, and discussed in this chapter. VML is deemed out-dated since it is a
rejected World Wide Web Consortium (W3C) standard and is only supported by
Internet Explorer (Zaslavsky 2003).
3.2.1 Proprietary Technology
The business models of software companies producing proprietary technologies
and software are, by and large, based on licensing. Customers purchase a number of
licenses which have to be renewed annually, or for each update. Usually, not the
vector rendering technology itself is licensed, but auxiliary tools for creating the
content.
Proprietary technologies and associated authoring tools are geared towards the
designer community creating Web-based content, as well as programmers using
various frameworks and code libraries for the development of Web applications.
The two most widely used proprietary products are Adobe Flash and Microsoft
Silverlight. They both provide high-performance authoring tools for graphic
designers and programmers.
3.2.1.1 Adobe Flash
Originally developed by Macromedia, Adobe Flash was designed for animated
Web-based vector graphics. Adobe’s marketing targets graphic designers and
authors of Rich Internet Applications (RIA). This orientation is reflected in the
development of new tools, with Flash/Flex being the most well-known for applica-
tion development (Noble and Anderson 2008). Currently, the cross-platform and
cross-browser framework Flex comprises MXML (an XML-based vector graphics
description language), ActionScript (a JavaScript-related language) and, for ren-
dering, either the Flash browser plug-in, or the Adobe Integrated Runtime (AIR) for
desktop applications. MXML is capable of describing various graphical user
Table 3.1 Base technologies for Web-based vector mapping
Technology/software Company/consortium Authoring tools Format
Flash/Flex Adobe Flash Builder, Flash Professional Proprietary
XAML/Silverlight Microsoft Expression Blend, Visual Studio Proprietary
SVG W3C Illustrator, Corel Draw, Inkscape,
XML Editors
Open
JavaFX Oracle/Sun NetBeans, Eclipse Open
Canvas WHATWG/W3C – Open
WebGL Khronos Group Open
3 Current Trends in Vector-Based Internet Mapping: A Technical Review 25
interface (GUI) components and vector objects. In addition, raster graphics, filter
effects, videos, sound, animations etc. can be defined with MXML. User interaction
can be realized with custom MXML ActionScript code.
Various authoring programs allow for the generation of Adobe Flash content.
For designers, Adobe provides the visual design environment Flash Professional,
while programmers draw on the tools from Adobe Flash Builder. In a typical
workflow, either an MXML file is created using Adobe Flash Builder, or FLA
files and/or ActionScript classes are created using Adobe Flash Professional. The
resulting files are then compiled to a binary SWF file and presented with the Flash
plug-in or the Adobe Integrated Runtime (AIR).
Advantages of the Flash framework include the performant rendering engine, the
integration of multimedia content (e.g., video, sound and animation), a wide range
of auxiliary tools for designers, and the wide-spread dissemination of the Flash
Player for rendering Flash content. Adobe claims Flash Player is installed on more
than 98% of Internet-enabled desktops worldwide (source: adobe.com/products/
flashplayer/faq). Among the disadvantages of Adobe Flash, there are the depen-
dency on one software vendor who may arbitrarily change the code base or the
functionality of tools and plug-ins. Also, security concerns are raised when using a
plug-in, particularly in regard to arbitrary, remote code execution and passing on of
cached user information (Bradbury 2010).
Yet, Flash remains popular in the graphics industry. Typical use cases include
games and multimedia graphics with animation or video, advertisement banners,
and RIAs of varying complexity. Due to its wide dissemination, GIS and Web-
mapping applications feature built-in map export functionalities compatible with
Adobe Flash Player. An example is ESRI’s ArcGIS API for Flex on top of the
ArcGIS Server, which allows map authors to design customized interactive Web-
maps, with options to edit or query data, and integrate temporal data.
3.2.1.2 Microsoft Silverlight
Microsoft’s counterpart of Adobe Flash, the cross-platform and cross-browser
Silverlight framework, consists of an XML-based vector graphics description
language, known as XAML, which may be manipulated by various programming
languages, such as C#, VB.NET, or JavaScript. Silverlight uses a subset of the
Microsoft .NET framework, particularly the Windows Presentation Foundation
(WPF). The necessary browser plug-in is available for Windows and Mac OS X
and is installed on 50% of desktop computers worldwide (source: riastats.com).
Two authoring tools are available from Microsoft for generating Silverlight
content: The visual authoring environment Microsoft Expression Blend for
designers and the code-based Microsoft Visual Studio for programmers. In a typical
workflow, a XAML file is created with Expression Blend or Visual Studio, com-
piled to a binary XAP file, and then presented in the browser by means of the
Silverlight plug-in.
26 C. Lienert et al.
The performant rendering engine, the integration of multimedia content, and the
availability of auxiliary tools for programmers are the main advantages of the
Silverlight framework. The disadvantage in terms of the dependency on one single
software vendor is similar to Adobe Flash.
Silverlight is suitable for programmers experienced with the Microsoft Windows
.NET framework. It is supported by various development tools and Microsoft’s
dominant market position adds to its successful diffusion. Typical use cases include
business applications. ESRI, traditionally closely connected to Microsoft, supports
Silverlight with a separate API for creating interactive maps.
3.2.2 Open Standards
Open-source software is freely available and users may directly contribute to its
enhancement by extending specific functionalities and publishing new code. In this
section, four open-source technologies are discussed: Scalable Vector Graphic
(SVG), Oracle/Sun JavaFX, WHATWG/W3C Canvas, and WebGL.
3.2.2.1 Scalable Vector Graphics (SVG)
SVG is a XML format for vector graphics. SVG is a recommended standard of the
W3C consortium that all modern Web-browsers draw without the use of a plug-in,
including Chrome, Firefox, Internet Explorer (as from version 9), Opera and Safari.
However, the level of SVG support considerably varies between the different
browsers. The SVG specification includes vector and raster graphics, filter effects,
point symbols, masking, animation, and many other features (Neumann and Winter
2003). SVG is extendable with JavaScript, allowing for the creation of interactive
graphics and graphical user interfaces.
Among the applications capable of creating SVG content are Adobe Illustrator,
Inkscape, Xara Extreme, and Open Office Draw for designers, or different XML
editors for programmers. In a typical workflow, an SVG file is created containing
geometry data, and a separate JavaScript file with the application logic (e.g., the
interactive functions).
The main advantages of SVG are the direct support in browsers, and the large
variety of vector elements and visual effects. Another major advantage is the
possibility to use multiple coordinate systems in a single drawing, which makes
the SVG standard attractive for mapping applications: map features are based
on native geographic coordinates, while user interface elements use screen
coordinates.
The disadvantages of SVG are the sub-optimal support for multimedia, and the
slow rendering. This issue is currently addressed by browser authors. Internet
Explorer 9, for example, will introduce hardware accelerated SVG rendering.
3 Current Trends in Vector-Based Internet Mapping: A Technical Review 27
3.2.2.2 JavaFX
JavaFX, now developed by Oracle, is a cross-platform and cross-browser framework
for the development of Rich Internet Applications (RIA). It is based on the Java
Runtime Environment, which is installed on about 75% of desktop computers
worldwide (source: http://riastats.com). The tools needed for generating JavaFX
content are NetBeans or Eclipse, both Integrated Development Environments (IDE)
for experienced programmers. In a typical workflow, JavaFX code is compiled to
Java bytecode and saved to a JNLP or JAR file. These files are then passed to the
browser and executed using the Java Runtime Environment or Java Micro Edition on
mobile phones.
Among the advantages of the JavaFX framework are the integration of Java
drawing classes, and the thorough security concept. However, starting up the
JavaFX plug-in is slower than starting up Silverlight or Flash. Another major
disadvantages are missing tools for designers. Integrating multimedia elements,
such as video and sound, is possible; but owing to the lack of authoring tools,
JavaFX is mainly used by experienced programmers. Being an open-source frame-
work with a thorough security concept, JavaFX comes into play for developing
large business applications in which maps may be an integral part. However, for
Web applications, it is currently not as widely used as is Flash or Silverlight. It
should also be noted that with the release of JavaFX 2, the hitherto recommended
JavaFX scripting language will not be developed any further.
3.2.2.3 Canvas
Canvas is a HTML element, which uses JavaScript commands for drawing graphic
primitives (e.g., rectangles, paths, text). The Canvas version for drawing 2D
graphics is standardized by the Web Hypertext Application Technology Working
Group (WHATWG) and will be part of the upcoming HTLM5 specification.
HTML5 is the next major revision of the HTML standard, which is currently
under development by the W3C (Mansfield-Devine 2010). No browser plug-in is
required to render Canvas elements, as it is already implemented in Chrome,
Firefox, Opera, Safari, and Internet Explorer. Canvas is combinable with other
Web standards, but it represents a lower conceptual protocol level than, for exam-
ple, SVG, as it is not based on a built-in scene graph or a Document Object Model
(DOM). Drawing commands are not converted to graphical features for later access
or manipulation. Instead, each JavaScript drawing command immediately changes
the pixels of the generated image. After rendering vector data, only the individual
image pixels may be manipulated using JavaScript.
Currently, no mature graphic authoring tools exist for Web designers to create
Canvas drawings. Content is therefore mainly created by programmers using text
28 C. Lienert et al.
editors and custom-made code. In a typical workflow, a HTML file is extended with
JavaScript code drawing the Canvas graphics. The JavaScript code might be
embedded into the HTML file or stored in separate files. The browser automatically
loads the JavaScript when rendering the Canvas element.
In the future, Canvas has a considerable potential to compete established vector
data rendering technologies, such as Adobe Flash. The main advantages of the
Canvas element are the support by all browsers, the fast rendering, and its options
for raster data manipulation. The major disadvantage is the missing scene graph,
which complicates linking with event handlers for interactive graphics, and which
may considerably increase complexity when dealing with a large number of
complex graphical primitives.
3.2.2.4 WebGL
WebGL is a 3D graphics API for Web applications that extends the HTML Canvas
element. The specification is currently a work in progress, and implementations are
not yet finalized. WebGL is specified by the non-profit technology consortium
Khronos Group, which controls various open standards, for example, the OpenGL
standard for rendering 3D graphics.
Similar to the 2D variant of Canvas, three-dimensional drawing with WebGL is
controlled by JavaScript code without using a built-in scene graph. It accesses the
computer’s graphics card via the platform-independent OpenGL API which entails
a very high rendering performance. WebGL uses the OpenGL ES 2.0 standard, a
subset of OpenGL, which is also supported by devices with limited computing
power, such as smartphones, tablet computers and other mobile devices. WebGL
rendering is based on shader programs that calculate rendering effects on graphics
hardware with a high degree of flexibility.
WebGL is not yet part of Web-browsers for end users. However, developer
versions of Chrome, Firefox, and Safari contain experimental implementations. As
a consequence, WebGL is currently mainly applied by programmers and early
adopters for experimental applications.
Various scripting libraries are available to create WebGL content or for loading
3D objects that are designed with 3D modeling software (e.g., Autodesk 3ds Max).
JSON (JavaScript Object Notation) is often used to describe and load 3D objects.
The advantages of WebGL include very fast rendering, and the versatility
offered by shader programs for graphical special effects. Due to its early develop-
ment status and owing to the lack of authoring tools, expert programmers are the
exclusive user group of WebGL. Another disadvantage is the lack of support by
Internet Explorer. However, WebGL has a considerable potential for both 2D and
3D map visualization.
3 Current Trends in Vector-Based Internet Mapping: A Technical Review 29
3.3 Vector Overlay for Client-Side Mapping
In the previous section, independent general-purpose vector-based Internet standards
are discussed. The standards are implemented in Web-browsers, or require additional
plug-ins. The discussion is now moving towards a higher abstraction level, i.e.,
frameworks and APIs for mapping which build on these standards. Such client-side
frameworks and interfaces offer additional functionality for cartographic applications,
and encapsulate and further abstract the underlying visualization standards.
Client-side frameworks are widely used, since they greatly facilitate the creation
of vector-based Web maps allowing cartographers to focus on their core compe-
tency in design and data visualization. The concept of such toolkits is to provide an
API that allows map authors to create so-called mash-ups. Such maps usually
combine a raster map in the background with custom, overlaid vector data. Often,
the default graphical user interface provided by the API for manipulating the map is
also customized, either by using functionality of the mapping framework, or by
integrating specialized external libraries. The list below shows the most popular
toolkits for generating map mash-ups.
The Google Maps API, the Microsoft Virtual Earth/Bing Maps API, and the
Yahoo! Maps API offer similar functionality. They provide access to a multi-scale
worldwide raster map, and a specialized graphical user interface for navigating the
map. Authors work with a JavaScript based or a Flash-based API to embed their
map contents. A wide range of functionalities and services are available for data
integration and map drawing.
OpenLayers is a GUI and a customization tool for combining raster and vector
data sources. It consists of a JavaScript library for displaying map data in Web-
browsers, without any server-side dependencies. Unlike Google’s, Microsoft’s or
Yahoo!’s APIs, the OpenLayers API is entirely free and open-source. It is often
used in combination with OpenStreetMap, a freely editable map of the world.
The carto.net framework is for SVG based maps. By means of a programm-
ing language and the DOM (Document Object Model), SVG documents are
manipulated. The DOM allows any Web-enabled programming language to
create, manipulate, and delete map elements. In most cases, JavaScript is used
for these manipulations.
CartoWeb (www.cartoweb.org) and p.Mapper are two frameworks running on
MapServer, which is discussed in the next section. A graphical user interface and
customization tools for web maps are provided, using JavaScript on the client-side
and PHP MapScript on the server-side.
3.4 Vector Overlay for Server-Side Mapping
Web-map servers used to be restricted to raster-based output. Raster functionality
includes the tiling of data, the conversion of data to various formats, or the
resampling of raster images using different down- or up-scaling operators.
30 C. Lienert et al.
Nowadays, Web-map servers are increasingly able to produce vector graphics
formats. The concept is much the same as for client-side mapping: vector data are
handled as individual, addressable objects and often overlay background raster
data. Different Web-map servers share common characteristics, such as their
cross-platform and cross-browser capabilities, and their more or less strict support
of Open Geospatial Consortium (OGC) standards. In this section, a selection of
Web map servers are discussed in more details, with emphasis laid on vector
formats.
3.4.1 MapServer
Formerly known as UMN MapServer, MapServer is the most widely used open-
source map server worldwide. It is very popular with a large user community and
with numerous programmers who further develop functionalities and features.
MapServer is able to read data from a variety of enterprise geodatabases, such as
Oracle, IBM DB2, or PostgreSQL via ESRI ArcSDE. It can also read data from
spatial databases, such as Oracle Spatial, PostgreSQL/PostGIS, and from several
GIS file formats, such as ESRI shapefiles. The main cartographic features include
data filtering operations, anti-aliasing, on-the-fly projection, and visualization of
data in form of pie and bar charts. Beside its capability to output raster data
according to Web Map Service (WMS) versions 1.0, 1.1.1, 1.3.0, and Web Cover-
age Service (WCS) versions 1.0, 1.1.x, it also supports vector-based output
standards, such as Geography Markup Language (GML), SVG, PDF, and Web
Feature Service (WFS) version 1.0.0. In order to visualize vector output, the W3C
standard Styled Layer Descriptor (SLD) 1.0.0 may be applied, but usually, users
define the cartographic symbolization in a so-called mapfile. The advantages of
MapServer are its active user community, on-the-fly map projection, and its easy
integration in different Web servers, such as Apache and IIS. The fact that
MapServer does currently not fully support SLD may be viewed as a disadvantage.
3.4.2 QGIS Mapserver
This open-source map server is based on Quantum GIS (QGIS), which is a free and
open-source desktop GIS. It has a rather small, but very active user and developer
community, mainly based in Europe. QGIS mapserver is able to read various data
sources, ranging from ESRI Shapefiles to GML, or spatial databases like
PostgreSQL/PostGIS. It features anti-aliasing and visualizes geodata by means of
patterns, point symbols, or pie and bar charts. Beside the raster-based WMS 1.1.1
and 1.3.1 output, QGIS mapserver supports the vector-based output standards
GML (Geography Markup Language), and WFS (Web Feature Service) in combi-
nation with SLD (Styled Layer Descriptor) 1.0.0. The SLD symbolization
3 Current Trends in Vector-Based Internet Mapping: A Technical Review 31
description file is typically generated using the Quantum GIS desktop application,
or the associated PublishToWeb plug-in.
Among the advantages of QGIS mapserver are the fast rendering, and the
possibility to visualize geodata as diagrams, patterns and point symbols, together
with the full support for SLD. Another advantage is the integration in the
Quantum GIS desktop application, making the functionalities of QGIS mapserver
accessible to a wide user group. A disadvantage remains the small number of active
developers.
3.4.3 GeoServer
GeoSever is an entirely Java-based open-source map server. Its worldwide commu-
nity is large and active. GeoServer can handle data directly from most common
spatial databases. PostgreSQL/PostGIS, IBM DB2 with Spatial Extender, Oracle
Spatial, and ArcSDE, as well as standard GIS file formats such as ESRI Shapefiles
are manipulable through GeoServer. Some of the advantageous features are the
ability for anti-aliasing, versioning, and its security concept. Beside the most
current raster-based standard outputs (see above for QGIS mapserver), GeoServer
also exports to the vector formats WFS 1.0 and 1.1, PDF, SVG, KML, GeoRSS
(geocoded Web feeds), as well as GML 2.1.2 and 3.1.1. It also fully supports SLD
to create cartographic symbolization. GeoServer runs predominantly on the Apache
Web server. The support by its active community and by major software companies
is an additional advantage.
3.4.4 ESRI ArcGIS Server
This proprietary and popular map server allows users to link to the ESRI GIS
software portfolio. Using ArcSDE, it handles spatial databases, such as Oracle
Spatial, IBM DB2, and PostgreSQL/PostGIS, as well as a range of GIS file formats.
Beside anti-aliasing, filtering, and 3D output, it also offers a variety of geo-
processing functionality. ArcGIS Server is able to export raster-based data according
to the most current standards, and also provides vector-based output, such as WFS
1.0 and 1.1, GML 2.0 and 3.1, KML 2.1 and 2.2. For cartographic symbolization,
SLD 1.0 is supported. ESRI ArcGIS Server offers different Web-services, which are,
however, typically conceptualized using the Desktop ArcGIS. The same applies to
the definition of the cartographic symbolization. Among the major advantages are
the geo-processing functionalities and 3D output.
32 C. Lienert et al.
3.4.5 Intergraph Geomedia WebMap
This software is another proprietary map server which handles spatial databases
such as Oracle Spatial and Microsoft SQL Server. Geomedia WebMap is able to
export WMS and different raster formats, as well as vector-based standards, such as
WFS, GML, or SVG. Geomedia WebMap is mainly used in the business sector.
3.5 Web-Based Vector Map Examples
The following two map examples illustrate how geographic data may be visualized
by vector-based Internet maps. The example in Fig. 3.1 contains hydrological
real-time data which are automatically edited, processed, and visualized in an
interactive vector map, along with interactive time series graphs. The map is
based on data stored in a real-time PostgreSQL/PostGIS database which are auto-
matically converted to SVG. The real-time visualizations have been created on the
basis of the carto.net SVG framework and have been extended with specific
interactive GUI components.
The example in Fig. 3.2 shows a city plan accessible to administrative officials as
well as to the general public. The map is based on Microsoft Silverlight technology.
Most of its content is delivered as WMS raster data using the ArcGIS Server via a
Fig. 3.1 SVG real-time map and time series graphs (Lienert et al., 2010)
3 Current Trends in Vector-Based Internet Mapping: A Technical Review 33
REST API and integrated in a Silverlight GUI. Vector-based interactive objects,
such as points of interest and borders, are placed over the raster background. The
vector data in this example are stored in an Oracle Spatial database.
3.6 Conclusions
Vector-based Internet technologies are continuously developing and changing, with
new standards and formats appearing, and old ones disappearing. The number of
technologies may seem confusing, but at a technical level, similarities between the
different technologies prevail: the use of equal graphical primitives (e.g., SVG and
Silverlight), the integration of multimedia (e.g., Flash and Silverlight), and the use
of JavaScript, or derivates thereof, outweigh the differences between the
technologies, which are mainly rendering speed and the underlying authoring and
programming environments.
The anticipated move from desktop applications to purely Web-based
applications and services may drive browser vendors to further adopt Web-mapping
standards and workflows (Jolma et al., 2008). Currently with self-contained mobile
applications (so-called Apps) on the rise, however, the Web-browsers are not the
ubiquitous user interface for which many were hoping (Kennard and Leaney 2010).
Thus, a standardization of formats for vector-based Internet graphics is not to be
expected soon.
Table 3.2 shows application domains and the disseminations of vector-based
Internet mapping technologies by beginning of 2011, for different user groups and
for different use cases. This table is surely subject to rapid change. A wide range of
Fig. 3.2 Silverlight city map (www.stadtplan.stadt-zuerich.ch)
34 C. Lienert et al.
mapping frameworks and authoring tools cover various skill levels, some straight-
forward, others guided, yet others still experimental. However, the cartographers’
choice of vector mapping technology certainly also correlates to their technical and
programming skills.
Since authoring tools facilitate the map making process, technologies such as
Adobe Flash and Flex, or Microsoft Silverlight may better meet the needs of design-
oriented cartographers. Their popularity and diffusion is accordingly high. Due to
their code-based environment and required programming skill, the features offered
by software applications such as JavaFX, Canvas or WebGL reach a smaller
number of cartographers. These technologies, however, enjoy growing popularity
and may be complemented by some authoring tools in the future.
Client-side and server-side frameworks allowing for vector data overlay are
becoming increasingly popular and are found on numerous commercial and non-
commercial websites. There is also a trend for mapping software on mobile devices,
such as cell phones, to adopt this overlay concept. For many map authors, client-
side frameworks constitute a widely used basis for building customized maps.
These frameworks provide free raster-based, multi-scale background world maps
as well as functionality for custom vector data overlays. Technically more adept
cartographers with more computer science expertise, in turn, may set up a Web map
server for generating custom base maps combined with vector data overlays.
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Table 3.2 Application and dissemination of vector-based Internet mapping technologies
Technology/
software
Targeted authors Typical use cases Authoring
tools
Dissemination
Flash/Flex Designers and
programmers
Multimedia, advertisement,
games
++ Very high
XAML/
Silverlight
Designers and
programmers
Business applications ++ Medium
SVG Designers and
programmers
Infographics (diagrams,
maps)
+ High
JavaFX Programmers Business applications + High
Canvas Programmers RIAs, infographics, games High
WebGL Programmers 3D graphics (experimental) Low
3 Current Trends in Vector-Based Internet Mapping: A Technical Review 35
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... In terms of methodological and technical considerations, audiovisual maps had commonly been created with proprietary software for quite a long time, such as Macromedia (later: Adobe) Flash (e.g., Feringa 2001; Lienert et al. 2012;Muehlenhaus 2018). These software solutions allowed the connection between a media library (incl. ...
... For a long time, multimedia cartography, incl. webbased multimedia cartography, was methodically handled with techniques offered by proprietary animation software Fig. 10 Implementing mp3 files into iframe elements within a popup bound to a marker products, such as Adobe Flash (e.g., Lienert et al. 2012;Muehlenhaus 2018;Siepmann et al. 2019). The general availability of the Internet as well as the rising demand for mobile devices required a rethinking of making maps that are accessible for individual user-purposes (see also Fish and Calvert 2016;Hurtig and Scharlach 2018). ...
Article
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Audio files entered cartography about 25 years ago. Since the mid-1990s, several examples of audiovisual maps have been created and published. These maps cover a diverse range of applications. In terms of the sound elements implemented, four characteristic variants were mainly used: abstract sounds/sound sequences, language recordings, and music and recordings/simulations of the real soundscape. To built audiovisual maps technically, several tools of animation software solutions were intensively explored. The rising importance of the World Wide Web also increased the demand for new and modern web-based approaches of multimedia cartography. One of the core technologies of the Internet is the programming language JavaScript (JS). The language is often associated with the so-called libraries which are applied programming packages pre-written for particular purposes. In cartography, one of the most popular and widely used JS libraries is leaflet.js. This open-source library is known for its simplicity and, meanwhile, it also supports a straightforward integration of multimedia content, such as audio files. It also teams up with HTML5 and CSS3. This paper intends to give a workflow focused on how to create individual audiovisual web mapping applications based on the contemporary options offered by leaflet.js.
... ch.bfs.gebaeude_wohnungs_register,ch.bav.haltestellenoev,1,1,0.8&layers_visibility=false,;(b) https://test.map.geo.admin.ch/? topic=ech&lang=fr&layers=ch.swisstopo.zeitreihen,ch.bfs.gebaeude_wohnungs_register,ch.bav.haltestellenoev,ch.swisstopo.swisstlm3d-wanderwege&layers_opacity=1,1,1,0.8&layers_visibility=false,false,false,false&layers_timestam 10 L'utilisation des tuiles vectorielles par rapport aux tuiles raster présente de nombreux avantages tant au niveau des performances, des capacités de rendu que de l'interactivité (Lienert et al., 2012 La personnalisation des fonds de carte comme nouvelle pratique 16 L'autre atout majeur des tuiles vectorielles réside dans la possibilité de modifier à la demande la symbologie des entités spatiales grâce aux feuilles de styles (Hayat, 2017). Il est ainsi possible de construire de manière dynamique ses propres fonds de carte selon ses goûts, la thématique traitée ou une charte graphique sans avoir besoin de régénérer des tuiles. ...
... ch.bfs.gebaeude_wohnungs_register,ch.bav.haltestellenoev,1,1,0.8&layers_visibility=false,;(b) https://test.map.geo.admin.ch/? topic=ech&lang=fr&layers=ch.swisstopo.zeitreihen,ch.bfs.gebaeude_wohnungs_register,ch.bav.haltestellenoev,ch.swisstopo.swisstlm3d-wanderwege&layers_opacity=1,1,1,0.8&layers_visibility=false,false,false,false&layers_timestam 10 L'utilisation des tuiles vectorielles par rapport aux tuiles raster présente de nombreux avantages tant au niveau des performances, des capacités de rendu que de l'interactivité (Lienert et al., 2012 La personnalisation des fonds de carte comme nouvelle pratique 16 L'autre atout majeur des tuiles vectorielles réside dans la possibilité de modifier à la demande la symbologie des entités spatiales grâce aux feuilles de styles (Hayat, 2017). Il est ainsi possible de construire de manière dynamique ses propres fonds de carte selon ses goûts, la thématique traitée ou une charte graphique sans avoir besoin de régénérer des tuiles. ...
... They developed universal support for the open web language standards of CSS (Cascading Style Sheets) for page styling, SVG (Scalable Vector Graphics) for vector image rendering, HTML5 for content layout, and JavaScript for programming tasks (Roth et al. 2014; also see Figure 1). Higher bandwidths also became increasingly prevalent in the developed world (Lienert et al. 2012;Nielsen 2016). Additionally, the World Wide Web Consortium (W3C) promoted a shift away from proprietary, third-party technologies toward free and open source (FOSS) tools based on open web standards that ensured royalty-free use and modification (Lund 2017). ...
... They developed universal support for the open web language standards of CSS (Cascading Style Sheets) for page styling, SVG (Scalable Vector Graphics) for vector image rendering, HTML5 for content layout, and JavaScript for programming tasks (Roth et al. 2014; also see Figure 1). Higher bandwidths also became increasingly prevalent in the developed world (Lienert et al. 2012;Nielsen 2016). Additionally, the World Wide Web Consortium (W3C) promoted a shift away from proprietary, third-party technologies toward free and open source (FOSS) tools based on open web standards that ensured royalty-free use and modification (Lund 2017). ...
Article
Most maps are now consumed online, yet colleges and universities struggle to keep their cartography and GIScience curricula up to date with the use of modern web technologies. I present a qualitative interview study aimed at providing insight into current teaching practices, along with challenges that may hamper the uptake of web mapping technologies in the classroom. The study involved interviews with 20 instructors of web mapping courses at colleges and universities in the United States and Canada. Participants were asked about the overall vision for their web mapping courses, the scope of material covered, what specific topics are included, which web technologies they use and why, their preferred teaching pedagogy, and what challenges they have experienced. The results highlighted several strategies that cartography and GIS instructors can use to implement or increase the inclusion of web mapping in their curricula.
... Finally, browsers can use multiple rendering techniques and provide different Application Programming Interfaces (APIs) for them. These techniques named Document Object Model (DOM), HTML Canvas 2D Context (Canvas), and WebGL, perform differently (Lienert et al. 2012). For performance reasons DOM can be rarely found in modern Web GIS applications, however Canvas and WebGL are popular technologies. ...
Conference Paper
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This paper presents a Web-based implementation of the coverage model, which was proposed to extend the traditional raster model. While the coverage model is able to overcome the most severe disadvantages of the raster model (e.g. reprojection, sampling bias), its vector-based display model needs more computational power. In order to create a proof of concept, the web mapping library OpenLayers was used as a basis for the implementation. After several failed attempts, the final program was able to render the Spearfish60 DEM from GRASS GIS’s example data feasibly. While both the rendering speed (20.8 fps) and the memory footprint (112 MiB) can be improved in the future, the results are promising for the first viable implementation.
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Here we present a flatmap of the mouse central nervous system (brain) and substantially enhanced flatmaps of the rat and human brain. Also included are enhanced representations of nervous system white matter tracts, ganglia, and nerves, and an enhanced series of ten flatmaps showing different stages of rat brain development. The adult mouse and rat brain flatmaps provide layered diagrammatic representation of central nervous system divisions, according to their arrangement in corresponding reference atlases: Brain Maps 4.0 (BM4, rat) (Swanson, 2018), and the first version of the Allen Reference Atlas (mouse) (Dong, 2007). To facilitate comparative analysis, both flatmaps are scaled equally, and the divisional hierarchy of gray matter follows a topographic arrangement used in BM4. Also included with the mouse and rat brain flatmaps are cerebral cortex atlas level contours based on the reference atlases, and direct graphical and tabular comparison of regional parcellation. To encourage use of the brain flatmaps, they were designed and organized, with supporting reference tables, for ease‐of‐use and to be amenable to computational applications. We demonstrate how they can be adapted to represent novel parcellations resulting from experimental data, and we provide a proof‐of‐concept for how they could form the basis of a web‐based graphical data viewer and analysis platform. The mouse, rat, and human brain flatmap vector graphics files (Adobe Reader/Acrobat viewable and Adobe Illustrator editable) and supporting tables are provided open access; they constitute a broadly applicable neuroscience toolbox resource for researchers seeking to map and perform comparative analysis of brain data. This article is protected by copyright. All rights reserved.
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Recent trends show that developers behind some of the most popular web mapping libraries put excessive work into creating custom hardware-accelerated rendering engines. Other libraries focus on functionality rather than visualization. From the perspective of the developer using these libraries an important question arises: is it necessary to use a WebGL-powered library for 2D web mapping? The answer was found through the implementation and evaluation of a simple WebGL ren-derer for the open source Web mapping library OpenLayers. It extends the previous, texture-based implementation with line-string, polygon, and label-rendering capabilities. Through various benchmarks, the benefits of using a WebGL rendering engine over the traditional, but nowadays widely supported and-in most cases-hardware-accelerated HTML5 Canvas renderer are assessed. Contrary to the current trends in Web mapping, results suggest that using the Canvas Application Programming Interface (API) is sufficient for smaller Web maps (up to around 2000 features and 60,000 vertices) using static vector data. WebGL only gives a noticeable performance boost with maps using large vector layers, such as Web GIS clients.
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The main aim of this dissertation was to discover the differences between user aspects of interactive 3D maps and static 3D maps and to examine the way in which users with different levels of experience work with interactive 3D maps. First, a literature review was conducted. Based on this review, the requirements for application enabling user testing of interactive 3D maps were defined. The testing application was then implemented using an iterative approach (according to a spiral model). The developed application 3DmoveR (3D Movement and Interaction Recorder) is based on a combination of the user logging method, a digital questionnaire and practical spatial tasks. From this application, the 3DtouchR (3D Touch Interaction Recorder) and 3DgazeR (3D Gaze Recorded) variants were derived. Nine partial experiments were carried out. Four of these experiments were exploratory and verified the functionality of the applications and demonstrated the ability to analyse and visualise the recorded data. Two experiments compared static and interactive 3D maps, while one compared real-3D and pseudo-3D visualisations. In two experiments the performances of different user groups (experts on geography versus laypersons, digital natives versus digital immigrants) were compared when working with interactive 3D maps. Experiences with the design and realisation of user testing of interactive 3D visualisations, which were gained during these experiences, were summarised, and a list of recommendations for interactive 3D visualisation user testing and analysis of these data was formulated. A decision tree for selecting appropriate methods of user interaction and virtual movement analysis was created. The main findings regarding 3D maps are as follows: • Interactive 3D maps are suitable when a correct decision is needed and there is no time pressure with regard to the decision-making speed. • Interactive 3D maps are suitable for more complex tasks. • Interactive 3D maps are more suitable for experts on geospatial data. • Real-3D visualisation increases the accuracy of user responses when working with static 3D maps, but this difference is less significant when working with interactive 3D maps. In general, the benefits of interactive 3D maps are influenced by the purpose of the map, the map use conditions, the type and complexity of the map tasks and the map users. These outcomes are relevant, for example, when deploying interactive 3D maps in the fields of crisis management or geography education. There is also a clear recommendation for future user studies: If the experimental results should be generalised to interactive 3D maps and virtual reality, interactive 3D maps should be used as stimuli in this user studies.
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The mapping of spatiotemporal point features plays an important role in geovisualization. However, such mapping suffers from low efficiency due to computational redundancy when similar symbols are used to visualize spatiotemporal point features. This paper presents a similarity-based approach to predict and avoid computational redundancy, which improves mapping efficiency. First, to identify computational redundancy, the similarity of point symbols is measured based on commonalities in symbol graphics and symbol drawing operations. Second, a similarity-enhanced method is proposed to comprehensively predict and avoid computational redundancies when mapping spatiotemporal point features. This approach was tested using two real-world spatiotemporal datasets. The results suggest that the proposed approach offers relatively large performance improvements.
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To successfully transmit spatial information, maps must be well-designed. There exists a canon of design guidelines for paper maps, but a concise compilation of guidelines for the design of web maps is currently not available. This chapter contributes to this need by providing recommendations and guidelines specific to the design of web maps. Topics include the choice of a viewing technology; the influence of limited screen resolution and anti-aliasing; minimum dimensions and distances for map features; the generalization of information density and geometry; problems of screen typography; color rendition and; the design of user-friendly navigation tools. Some of these guidelines are based on the authors’ mapping experiences, while others were deducted from the observation of Internet user behavior or compiled from selected sources.
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Many software projects spend a significant proportion of their time developing the User Interface (UI), therefore any degree of automation in this area has clear benefits. Such automation is difficult due principally to the diversity of architectures, platforms and development environments. Attempts to automate UI generation to date have contained restrictions which did not accommodate this diversity, leading to a lack of wide industry adoption or standardisation. The authors set out to understand and address these restrictions. We studied the issues of UI generation (especially duplication) in practice, using action research cycles guided by interviews, adoption studies and close collaboration with industry practitioners. In addressing the issues raised in our investigation, we identified five key characteristics any UI generation technique would need before it should expect wide adoption or standardisation. These can be summarised as: inspecting existing, heterogeneous back-end architectures; appreciating different practices in applying inspection results; recognising multiple, and mixtures of, UI widget libraries; supporting multiple, and mixtures of, UI adornments; applying multiple, and mixtures of, UI layouts. Many of these characteristics seem ignored by current approaches. In addition, we discovered an emergent feature of these characteristics that opens the possibility of a previously unattempted goal – namely, retrofitting UI generation to an existing application.
Book
1 International Perspectives on Maps and the Internet: An Introduction Michael P. Peterson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Delivering geospatial information with Web 2. 0 William Cartwright . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3 Map design for the Internet Bernhard Jenny, Helen Jenny, Stefan Räber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 4 Web Cartography and the Dissemination of Cartographic Information about Coastal Inundation and Sea Level Rise Mark Monmonier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 5 An Elastic Map System with Cognitive Map-based Operations Naohisa Takahashi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 1 International Perspectives on Maps and the Internet: An Introduction Michael P. Peterson 1. 1 Introduction The Mosaic browser, the ? rst to support graphics, was introduced in 1993 and, at some point during that year, the ? rst map was transmitted through the Internet to a web page. Little notice was taken of the ? rst web map but the development of Internet cartography since has been nothing but remarkable. The new medium of communication changed maps from static entities on paper to dynamic products of interaction. Millions of maps are now created by servers every hour and transmitted through the Internet. When we need to ? nd a place or ? nd out about a place, we turn immediately to these servers through the Internet. In a few short years, the World Wide Web has transformed the Internet into the primary medium for the dissemi- tion of spatial information in the form of maps.
Chapter
Although the current web has been operational for about 10 years, vector graphics has been recently added to the World Wide Web (WWW) Consortium (W3C) standards set. Scalable Vector Graphics (SVG) became a W3C recommendation in September 2001. Before this, webpage developers that wanted to use vector graphics had to rely either on proprietary standards, or had to develop their own applets or plug-ins that could handle vector data. The new W3C SVG standard integrates vector graphics, raster graphics, and text; and it allows interactivity, scripting, animation, and special effects such as filters. SVG is based on Extensible Markup Language (XML), and it is fully localizable and extensible. It is the first seriously usable technology that offers cartographers high-quality graphics and interactivity, as well as multimedia integration, based on open standards. This chapter provides an introduction to vector graphics with the WWW and discusses the constraints of screen cartography. It also gives an introduction to the SVG feature set, presents some SVG mapping examples, and discusses current limitations and future planned enhancements.
Article
This chapter discusses online maps, which are increasingly becoming interactive representations from distributed information systems where multimedia spatial content is shared, combined, and styled for particular audiences and uses. This revolutionary change in Internet cartography has a lot to do with the advances in distributed computing, specifically the introduction of Extensible Markup Language (XML) and related technologies. The chapter reviews the principal technologies, experiences, and prospects of XML-based online cartography: the emerging XML standards for encoding spatial data, and their use for spatial data interchange and distributed mapping; the new XML-based languages for two-dimensional (2D) vector rendering, and their use in Web mapping; the use of XML for managing, browsing, and harvesting cartographic metadata, in support of spatial data infrastructure, spatial query processing, and information integration; and mapping applications based on the emerging XML Web Services standards. While providing an overview of XML based approaches and XML uses in Web cartography by a variety of vendors, it also highlights the experience in XML-based spatial data integration, and in the development of AxioMap (Application of XML for Interactive Online Mapping) software.
Article
Although the current web has been operational for about ten years, vector graphics was only recently added to the World Wide Web Consortium (W3C) standards set. Scalable Vector Graphics (SVG) became a W3C recommendation in September 2001. Before this, web page developers that wanted to use vector graphics had to either rely on proprietary standards or develop their own applets or plug-ins that could handle vector data. The new W3C SVG standard integrates vector graphics, raster graphics and text, allows interactivity, scripting, animation and special effects such as filters. SVG is based on XML, and is fully localizable and extensible. It is the first seriously usable technology that offers cartographers high-quality graphics and interactivity, as well as multimedia integration, based on open standards. This chapter provides an introduction to vector graphics with the WWW and discusses the constraints of screen cartography. Furthermore, it gives an introduction to the SVG feature set, presents some SVG mapping examples, and discusses current limitations as well as future planned enhancements.
Article
Browsers are the hackers' window into your PC – but how are they compromised, and what are vendors doing to harden them? Danny Bradbury examines the techniques vendors are employing, and why user education is one of the primary solutions for increased security
Chapter
Geospatial (geographical) software systems (GIS) are used for creating, viewing, managing, analysing and utilising geospatial data. Geospatial data can include socioeconomic, environmental, geophysical, and technical data about the Earth and societal infrastructure and it is pivotal in environmental modelling and management (EMM). Desktop, web-based, and embedded geospatial systems have become an essential part of EMM, providing pre- or post-processing of geospatial data, analysis and visualisation of results or a graphical user interface (GUI). Many local, regional, national, and international efforts are underway to create geospatial data infrastructures and tools for viewing and using geospatial data. When environmental attribute data is linked to these infrastructures, powerful tools for environmental management are instantly created. The growing culture of free/libre and open source software (FOSS) provides an alternative approach to software development for the field of GIS (FOSS4G). To provide an overview of FOSS4G for EMM, we analyse platforms, software stacks, and EMM workflows. In the FOSS world the barriers to interoperability are low and thus the software stack tends to be thicker than in the proprietary platform. The FOSS4G world thrives on the evolution of software stacks and platforms. We provide examples of software stacks built from current FOSS4G that support EMM workflows and highlight the advantages of FOSS4G solutions including opportunities to redistribute resulting modelling tools freely to end-users and to support general goals of openness and transparency with respect to modelling tools.
Chapter
As decision support in flood warning, experts within crisis management groups need readily available real-time data, and real-time visualization derived from them. Up until now, work steps including acquisition, harmonization, storage, processing, visualization and archiving of data have been accomplished manually or semi-automated. In a cartographic real-time application, these worksteps have to be achieved online and error-free. The presented web application and the generated real-time visualization products are based on a viable data model which is extendable by additional measurement or model ouput data. By means of a graphical user interface, users may overview the most current hydrological situation in the form of automatically processed real-time maps. In addition, these maps may be interactively compiled, depending on users’ needs, on different levels of detail, and in various thematic combinations. In order to classify the most current hydrological situation in the historical context, i.e., to eventually learn from the past, the application also allows to easily create visualizations of past flood events. Data from a long-term, high-resolution archive undergo the same cartographic rules and abstraction as real-time data for the purpose of direct comparisons.