ARTICLE JULY / AUGUST 2003 SMALL IS BEAUTIFUL While tremendous strides have been made to improve graphics and image design protocols for conventional desktop and laptop computers, there are many constraints in more mobile devices because of more limited memory, processing power and bandwidth. Yet there is a need to ensure compatibility between desktop/laptop computers and the more mobile world. The World Wide Web Consortium (W3C) ? the well-established international industry consortium driving the development and testing of global web standards ? has recently introduced a much more developed version of graphics rules based on open standards and modular building blocks that can be tailored specifically for mobile applications. W3C launched its initial Scalable Vector Graphics (SVG Version 1) recommendations in 2001 to improve overall web interoperability. Profiles match applications W3C?s new SVG Version 1.1 recommendations, issues in January 2003, separate SVG capabilities into reusable building blocks that can be combined in subsets or profiles to match specific applications. And, at the same time, W3C has offered two specific Mobile SVG profiles that make use of these blocks to provide an optimum approach for hand-held devices: SVG Tiny, aimed at multimedia-ready mobile phones, and SVG Basic, intended for hand-held and palmtop computers. Conformance to either the SVG Tiny or Basic profiles, rather than manufacturers selecting their own subset, will ensure widespread interoperability of contents on mobile devices from different suppliers. Such interoperability will offer content creators several advantages:
And, as Mobile SVG is a subset of SVG 1.1, all compliant desktop players will also be able to display all Mobile SVG content correctly, enabling mobile and desktop applications to continue to share a common, standards-based web. Rich graphics language SVG provides a rich graphics language that basically describes two-dimensional graphics in the web-standard Extensible Markup Language (XML). It allows for three types of graphic object: vector shapes (straight lines and curves), images and text. These objects can be grouped, styled and transformed into rendered objects. SVG drawings can also be interactive and dynamic ? allowing animations either embedded in the SVG content or through scripting. An initial application for SVG is in replacing the JPEG and GIF formats now used widely on the web. SVG offers many advantages over these two common graphic formats, including excellent scalability, as it is a vector format rather than bitmapped. This also means that text can be searched and selected, and sophisticated interactivity is possible ? such as zooming in on a selected item in a diagram to obtain more information. In addition, vector-based SVG graphic files are smaller than with current compressed bitmap formats. SVG has already been widely adopted by graphics vendors, with most of the major software producers incorporating it into their design packages. For example, Corel has incorporated SVG in its Draw and Illustrator packages and is providing a SVG Viewer plug-in. The basic difference between SVG 1 and SVG 1.1 is the way the graphics language is defined ? moving from a document type definition (DTD) in the original that was a single, monolithic unit to smaller, much more flexible functional building blocks that can be reassembled as required for different applications. SVG modularisation is based on the techniques pioneered by the HTML working group for XHTML modularisation. More colourful and useful content Screens on hand-held PDAs and mobile phones are increasingly able to display standard web technologies. Mobile SVG is already being incorporated into third-generation (3G) phones, making it possible see richer and more useful contents. SVG Tiny allows colourful animated multimedia messages rather than standard text or bitmapped logos to be sent to these new generation mobile phones. And SVG Basic enables consultation of dynamically updateable, interactive graphics on a convenient pocket computer or other easily portable wireless device. SVG 1.1 functional modules can also be combined with building blocks from other W3C technologies to produce ever more powerful and integrated solutions. For example, SVG building blocks can be combined with Synchronised Multimedia Integration Language (SMIL) Basic to integrate vector graphics with streaming audio and video, or with XHTML and MathML for scientific and technical communications such as interactive graphs and diagrams. In addition, SVG is built on established open W3C technologies such as XML, cascading style sheets (CSS) and the document object model (DOM) application-programming interface. Moreover, it has received a rigorous review for internationalisation and web accessibility, simplifying integration with existing technologies to maximise application power. Technology taking off Deployment of SVG Mobile has already started for commercial applications, such location-based services using geographical metadata embedded in SVG. W3C was involved in the successful compatibility testing of 15 implementations in November 2002, covering both SVG Tiny and SVG Basic. As a result, SVG implementations are now available from many vendors for use in mobile phones or on PDAs, in addition to the increasing number for desktop and laptop computers. | |||
