What are Client-Side Image Maps?

An "image map" is an image (photo, artwork, graphic) that has an underlying map that takes the user to different HTML files, depending on where she/he clicks.

"Client-side" simply means that the browser (e.g. Netscape) figures out what to do when the user clicks somewhere. The browser is the "client" and the source of the web pages is the "server".

Until last year, all image maps depended on a "CGI script" which had to be installed and run on the server machine. New browsers now offer an option, where the instructions for the map behind the image are carried in the HTML page itself, instead of in a CGI script. This new method is called "client-side image maps".

Unless you are a system administrator, and familiar with script programming, there are substantial advantages to using a client-side image map:

you can do it yourself, with the skills you have
you don't have to notify or deal with the system administrator
your pages and image maps can be put up on any kind of server platform (UNIX, Mac, etc.)
you can experiment, see results and correct things on your own machine, without re-loading things to the remote server
some commercial sites charge money to set up a CGI script, and some charge for every time that script runs. Client- side avoids all those charges
some sites don't offer CGI scripting at all
with most browsers, the user can see where they are going to click before they choose - the URL line will change as they move their mouse

The only downside is: older browsers don't support client- side image maps. But they can be handled with standard text- based or HTML menus. Older browsers who click on an image map can be taken directly to alternative pages.

The following browsers support client-side image mapping:

Netscape 2.0 and above
Microsoft Internet Explorer
NSCA Mosaic
Spry Mosaic (they invented it).

APPLICATIONS FOR CLIENT-SIDE IMAGE MAPPING

Mostly I'm seeing these used for button bars. A longish bar is at the top or bottom of the pages, with about 7 options, all of them within one GIF image. Image maps can be used for all sorts of creative thing: you can have a photo, and when you click on various items, you are taken to different links. It could also be used with art, or to add comments to an image or graphic. I got interested in client-side image maps to give users information organized on actual maps of the world. Have a look at the maps, which are public domain (you can steal them for non- commercial use...). There is also a help file on how to use the maps, as well as a downloadable "zip" file containing all the maps, as well as alternative maps without the country names. Geographic maps make a good "table of contents" for some subjects, giving one organizational approach. They also help orient the user. For more info, visit my site at: http://www.alternatives.com/raven/index.html

Look for my "Raven's Tools" page, or the section I'm building on organized crime - that section uses client-side image maps of the world.