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Preparing intelligent graphics for interactive catalogs
 
Sigrid   Weidenbrück
  Director International Sales
  ITEDO Software
Siegburg   Germany
 
Biographical notice:
 
Sigrid Weidenbrück
 
Sigrid Weidenbrück joined ITEDO Software in 1990 as a Sales Assistant.
 
After working for 2 years in sales administration she joined the national sales department being responsible for account sales and reseller channels in Germany, Austria and Switzerland.
 
In 1995 she took over responsibility for international sales of ITEDO Software. Her responsibilities are to build up sales channels for all ITEDO products within the respective countries as well as respresent ITEDO in international events such CALS and SGML conferences, trade shows and specialist seminars around Technical Illustration and CGM.
 
Sigrid Weidenbrück holds a Diploma of Language Science in English and Spanish of the Fachhochschule Köln in Germany.
 
ABSTRACT:
 
The technical documentation industry is experiencing a rapidly growing demand for the delivery of Interactive Electronic Technical Manuals (IETMs) and other sophisticated forms of on-line, interactive documentation. This includes the distribution of these electronic documents on CD-ROM or over the Intra-/Internet. Factors motivating this trend include a reduction in printing costs, the timely delivery of more accurate and up to date information, and improved customer interaction with and accessibility of information. Customers are demanding electronic interactive documentation such as IETMs, and companies that can deliver are perceived as being more advanced, modern, and responsive to customer needs.
 
Most electronic documents now contain both text and graphics and some provide the option of viewing the graphics in-line with the text or in a separate window. The inclusion of graphics in electronic documents is no longer restricted to simple display on screen. More and more graphics are used for navigation purposes. To accomplish this hotspots need to be added to allow the user to click on certain parts of an illustration and cause some kind of action to happen.
 
Technical manuals that contain a large number of illustrations typically have many references within the text to the illustrations and will often contain a number of references to specific items within each illustration. For this reason, IETM developers want to provide links between these references and the illustrations.
 
A major drawback for illustrations in electronic catalogs was the use of raster files, such as TIFF, GIF and JPEG instead of vector formats. Raster files are very slow in displaying on screen. To speed up this process these files are typically inserted with a very low resolution. This, on the other hand reduces the quality of the displayed illustration substantially and makes zooming almost impossible. As a consequence, the use of raster files in electronic catalogs was not accepted by the users. The demand for high-quality vector graphics with interactivity is increasing rapidly.
 
The preparation of graphics for the use in interactive catalogs and IETMs has been very work intensive in the past. In most cases the so-called hotspots were inserted using an overlay technique. That means, the hotspot is not part of the graphic itself, but is defined as a region that covers part or all of the area in which the graphic is displayed. The hotspot definition is usually stored in a separate file that is used at runtime by the viewing application to determine the location of the hotspots. For example, HTML and web technology involve the generation of a clickable image map which defines hotspots for graphics on web pages.
 
There are several drawbacks to the current techniques used to define hotspots for graphics. Foremost is the problem of maintainability. Consider a typical technical manual with a large number of illustrations each with many hotspots. What happens if the graphics are modified? The hotspots are no longer in the right positions and have to be changed manually. Redefining those hotspots is a very tedious, time consuming and error prone operation.
 
Another shortcoming with current hotspot technology is that in many systems the hotspots must be rectangular or circular in shape. This limitation is not so bad if you are placing a single hotspot on top of an entire illustration, or if you are placing hotspots on text or buttons that are part of the illustration. But as soon as you want to start hot-spotting actual elements of an illustration, such as the various individual parts of a complex assembly, the requirement to use rectangular hotspots becomes problematic.
 
Furthermore, the lack of standards compliant graphics in electronic catalogs has been a major issue for the industry. With view to the future it is very important for a company to have all illustrations stored in one homogeneous data archive which should be based on a worldwide standard format. This means a format like CGM (Computer Graphics Metafile), an ISO standard which is independent from any hardware or software manufacturer. By using standard formats you can make sure that your illustrations will be still reusable in 25 years.
 
But besides being an independent standard, CGM offers some more advantages. CGM version 4 has everything you require from a data format: high-quality graphics, all existing data can be included (scans, converted CAD data) and preparation for interactivity. The so-called application structures of CGM version 4 open ways to store non-graphic data together with the illustration in one file. The ISO standard does not define a hotspot element directly in CGM, so a CGM profile is required o accomplish this. Especially the ATA (Air Transport Association) has taken a lead to develop profiles which include application structures describing hotspots.
 
In the seminar we will show a new way to prepare graphics for the later use in interactive environments. It will describe the definition of graphic objects and hotspots in the illustration using CGM version 4. Additionally, it will present ways to display CGM 4 files including hotspots in viewers, and the integration of graphics viewers into different environments (SGML/XML browsers, World Wide Web, etc.).
 
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