Net imaging takes a much finer line: Web Design

IF YOU have ever seen a multimedia program running on a CD-Rom, one with an abundance of large, colourful graphics that fit perfectly, you may wonder why the Web can't look like this.

Well, there is the obvious problem of bandwidth, so it takes too long to download all of this glorious content, but there are other reasons that have to do with the fundamental concepts upon which the Web was originally conceived. All it was originally intended to do was to be a quick and easy way for scientists to exchange articles with other scientists. Then someone had the bright idea of adding graphics.

The first graphic format to be introduced to the Web was the relatively obscure Graphic Interchange Format, otherwise known as GIF. I have a pre- Web Photoshop book, circa 1992, which lists different graphic file formats. All it says about GIF is that it was created by CompuServe and is most often used to exchange porno pictures. The more things change... But the original creators of the Web used this format because it recorded complex images as relatively small computer files.

Soon after that, the JPEG format was added as a better way to transfer photographs on the Web. As a result of this early adoption, these two file formats have been the way we have created Web pages ever since. In actuality, both GIF and JPEG are just different ways to do the same thing: they record how a graphic looks by splitting the image into a grid of tiny points and then record the colour of each point. On the computer screen this is called a bit map, where each dot, or bit, is mapped out and its colour and position recorded. Both GIF and JPEG use this bit map method to record an image, differing mostly in the way they compress this information to reduce the file size.

Despite the fact that these formats have served us well, there are several problems:

Large File Sizes - These files are generally quite large since every pixel has to be recorded separately. Even when compressed, they can take seconds, or even minutes, to download and on the Internet that means using less graphic content if you want to keep people's attention.

Unalterable - Once created, these images are difficult to change in an image-editing program and impossible to change online. You can stretch and distort images in the Web browser using the WIDTH and HEIGHT attributes, but if you actually wanted to change the size of the graphic , forget it. Once displayed in a Web page, that's it.

Static - GIFs and JPEGs can't move on the screen. You can create animations using the GIF format, but those are about as sophisticated as a children's flip animation book and usually create huge computer files leading to long downloads.

So what is the solution? Over the past few years there have been a few attempts to add new graphic file formats to the Web, mostly through the use of plug-ins. None of these have really caught on because they rarely provided significant improvements.

However, just a few weeks ago Macromedia (http://www.macromedia. com) proposed that its Flash graphic format be adapted as a standard. Flash records graphics as vectors rather than bitmaps. To draw a line on the screen, a vector graphic tells the computer where the line should start and stop and how thick the line should be, whereas a bit map would have to record each and every dot. Vector graphics can fit a lot of information about a graphic into a small file. Even better, you can resize these graphics at a whim.

The drawbacks? Currently, Flash graphics require the use of a plug-in if you want to use them on a browser. However, Netscape recently announced that its browsers will come with this pre-installed, and Microsoft can't be far behind.

Next week we'll explore the Flash format and vector graphics in greater detail.

E-mail questions or comments to Jason Cranford Teague at indywebdesign@mindspring.com