Internet mapping with XML
SVG mapping example phone: 800-627-2923email: rkgeorge@cadmaps.com
An increasingly important component in the GIS implementation process of the Internet GIS. Extend the user's range of GIS to a larger circle to bring a much larger return. In addition, customer satisfaction can also be strengthened by providing automatic information services on real reference databases, a recently held voting for GIS implementation tools, ask questions to be added to their GIS by investigators Map. The response to voting shows that more than half respondents say that they plan to extend their GIS range to the Internet in the second half of the year. The World Wide Web Alliance (W3C) has been conducted to be non-patented, and the open resource map lays the foundation. As these XML technology is more well known, the expansion of the GIS configuration will become easier and economical with Internet mapping.
The World Wide Web Alliance (W3C) is responsible for developing specifications for making the Internet into an open system. Basic standards, such as now popular HTML is developed and maintained by World Wide Web. Recently, W3C is actively expanding through an XML-based new generation standard.
One of the latest XML standards is SVG, scalable vector graphics. It provides a technical basis for the Internet-based GIS. With very flexible database coupling and a full range of custom vector maps (www.w3.org) can now be published on the Internet without patented software support.
SVG is an XML standard for vector graphics
SVG is an XML standard for planar graphics. It includes all elements for vector shape features, grating images, animation graphics, and text, and all public data type definitions or DTDs specified in the W3C. XML syntax or markup language can be handled with standard XML tools such as validity test parsers, editing, and browsing tools. Recently, as a proposed SVG recommended, SVG has been supported by several browsers, but still needs a plugin for the current MS IE and NetScape versions. Adobe offers a free SVG plug-in from them. (http://www.adobe.com/svg/viewer/install/) Adobe also bundles their viewers with Acrobat Reader and Real Audio, the purpose is to issue approximately 12 million in the next month Viewware. Finally, SVG is directly integrated into a major browser. SVG reflects the basic expansion of the Internet, which allows the vector design file to be accessed through the web.
The following screen illustrates a typical SVG mapping that is shown in MS IE 5.5 with an Adobe SVG viewer 2.0 plugin.
Figure 1 Denver City Map
The above show is a small part of a typical SVG file:
B>
City of deNVer
List 1 - Sample pieces showing typical feature tags
In this small list, we are easy to pick out some differences between circles, straight lines, text, and multi-vertest routes. The indentation is a typical thing of the XML syntax structure. Although it is still controversial, it is also easy to understand for those who are familiar with HTML language, not completely unrelated. One of the advantages of XML syntax is its openness. Computers and people can easily identify features and customize. SVG can be accessed by people with only some simple text editor in its original format. In addition, as a supporting XML syntax, a large heap of tool can be inserted into a complex modular system. The SVG that can be accessed as a text can also be combined into the specification to make it valid on the Web. SVG text files are also easy to compress and a typical SVG file will be transmitted on the Internet with the compression format with the .svgz extension.
As a vector description of the vector, there is a significant advantage in the current image technology: GIF, PNG, JPEG, Tife formats are a collection of points without intelligent connections. Even if it has advanced compression, the grating requires considerable file. These types of image formats must transmit the spatial space and the straight line itself. Vector image format, on the other hand, is a simple collection of Dikal space digital endpoint, because only the end point together with some mixed properties, you need to pass the Internet, download time can be quite shortened. When the Internet bandwidth is very popular, this is still important, but more important for bandwidth is the inherent scientificability of vector straight lines. Once in the client browser, the vector is scalable without need to access the server. To view the details, he is different from the mode of downgrade of the raster image. The raster image is clearly immediately piloted, but no matter from the external space or a submissions, the straight line is equivalent to another point. Graphics cards use a very effective linear algebraic and matrix transform engine, so vector can be effectively transmitted and displayed. SVG activated browser allows users to use zoom and hand tool control view, and we are also used to control views in this way in PC GIS software. SVG also includes standard image format, GIF, PNG, and JPG. The SVG vector feature can be overlaid on the grating image. This is possible to mix the grating / vector display. Below is a fragment in the SVG file of a JPG file:
It usually applies more to the art effect outside of the filter effect of the SVG specification to be applied to the image.
Figure 2 Vector COGO in a virtual JPG
SVG is not just vector display
Figure 1 explains the static aspect of SVG. However, the application of SVG is much greater than simple vector display. SVG is used as an XML standard and is fully compatible with the DOM 2 specification. This allows the SVG file to be dynamically operated on the client browser. Elements of an SVG file can be added, moved, modified, replicated, and deleted using the GUI event triggered by the client. These functions are easy to use for common descriptive languages such as JavaScript. It allows a dynamic customization within a free range. By a very simple JavaScript function, the mouse event is tied to the feature property, and a wide variety of client scrolling and pop-up volumes are possible.
Figure 3 - JavaScript with vector computing and table data created from the MySQL database is tied together
The SVG is also expanded with server-side technology in a complete customization of the client. Multi-bundled applications utilize typical server technology, such as Java Servlets, JSP, or ASP. The SVG chain contacts the sender event to query the database or implement complex server functions, which generates a new SVG document. At the client, the SVG is coupled to the server-side HTTP tunnel effect, like XML-RPC, RMI, and SOAP, allowing the SVG event to dispersion community. For example, a client browsing through the mapping hierarchy. These selection parameters are sent to the server. On the server, Java Servlets query the necessary input streams from one or several remote servers, eventually generated a new SVG display.
Figure 4 - Point mapping with a data query window, a detail amplification, and a JavaScript floating toolbar
SVG extended with Java technology provides a scalable, open solution for a range of Internet mapping applications. SVG is a portable data specification and Java is a portable application development tool. The Internet mapping scheme developed with these tools can be transferred to a wide range of hardware and operating systems. This prevents projects from being restricted in a single budget program that you can perform different budgets based on different sizes and different licenses. Open resource Apache organizations add a new solution to SVG. This new solution is called Batik, which provides an open resource Java tool for viewing, transcoding, skilled SVG resources. (Apache Batik Project) Adds MySQL to Linux on an Apache Jakarta / Tomcat server and service SVG mapping to reduce the cost of Internet access. SVG is also compatible with the entire range of XML specifications, this specification is now just applied to the Internet. XPath, XPointer, XQuery, XForm, XHTML, XSLT is only some XML technology for providing infrastructure for a rapidly expanding semantic network. As part of an XML infrastructure, SVG is in a solid central position in the current Internet technology. SMIL, synchronized multimedia integration language is one of the XML standards that allow SVG and media rich audio views and animations. For example: The rolling mouse event on the SVG chart can be used to trigger streaming audio files. (Voice Rollover) Media-rich Internet mapping applications can not only be used for SVG implementation, but it is easier to implement.
in conclusion
As the GIS community saw an expanded need to be expanded to the Internet, SVG will play an important role in providing powerful and economical solutions. In order to demonstrate the new XML syntax, GEOTECHNOLOGIES Co., Ltd. has developed a large number of Internet GIS applications (SVG Mapping).
"Semantic network is the extension of the current network. In the current network, the information gives a definition perfect meaning, which makes it better to cooperate with humans in work." - Tim Berners-Lee, James Hendler, Ora Lassila - Scientific American The Semantic Web
SVG Advantages
1. SVG is a non-patented - SVG is an open W3C specification!
2. XML-based SVG and additional XML standards - SMTL, XLINK, XPATH are compatible.
3. Text-based SVG is a manifest format, and allows the standard text to find a function.
4. XML Development Tools - Many developments can be used to process XML - Xalan, Xerces, SAX, JDOM ...
5. DOM Access -SVG is simple to customize JavaScript or VBScript language.
6. Scalability in Server Technology - Java Servlets, JSP, ASP, PHP, Pearl ....
7. Flexible implementation - Windows, Linux, IBM, HP, UNIX OSS
8. Allow multiple bundled structures - browser clients to the ISP server to the database
9. Compatibility with CSS Stylesheet - Project managers can judge the expression properties.
10. Development of non-GIS Software Integration --XML has across all rules and distributed development costs on a wide range of users.
11. SVG Intelligent Mapping - Intelligent connection graphic elements to a rich semantic network in a partner group.
Figure 5 - Database query connected to graphical features
To see more information and SVG applications, please visit our new website:
SVG Mapping DemonStrationsphone: 800-627-2923email: rkgeorge@cadmaps.com
