ImageMaps

ImageMaps are graphical images which can be clicked on in different locations to go to different links- as opposed to an image which is a link.

You can make an image a link simply by enclosing the image in an anchor statement:

<A HREF="TheLink"><IMG SRC="ThePicture"></A>

ImageMaps, however, let you link multiple different links to a single image. They are ideal for use when the location of the click has some meaning- they are a poor replacement for a simple text link.

ImageMaps can be server side or client side.

Server Side ImageMaps

When the user clicks on a server side image map the coordinates of the click are returned to a CGI running on the server. It is up to the CGI to deal with the coordinates and hand back a web page or a web page redirect.

Server Side ImageMaps require a CGI on the server and the browser can't display where the image map will go if you click there because it doesn't know- you need to make sure that the image makes clear where the user will go if they click on the ImageMap.

Server Side ImageMaps are the more widely supported than Client Side ImageMaps.

Client Side ImageMaps

With a Client Side ImageMap information about the map is uploaded to the browser and the browser handles any clicks in the picture. Most web browsers which support Client Side ImageMaps will display information about where a click in the picture will take you.

This is an example Client Side ImageMap:

Note: This is not a good use for an ImageMap. This could be done better by using, for instance, a sequence of individually linked images, or using a text bar (see the bottom of this page). ImageMaps are slow to load, don't resize to the window and take up a lot of extra space. I do not recommend using ImageMaps if they are really only there as decoration.

A good usage for an ImageMap would be a floorplan of a convention center where clicking on locations takes you to the booths in that area. Or a picture of a human skeleton with links to the pages describing the bones. In these examples the ImageMap provides a superior mechanism to text: the picture is worth a thousand words.

ImageMap Software

There is plenty of ImageMap software for the Macintosh. The ImageMap above was created using ImageMapper, a good utility which can create the map files for Client Side and Server Side Image maps.

Check out the WWW directories of Info-Mac and UMich, or do an AltaVista search to find alternatives.

info-mac/comm/inet/web/ mac/util/comm/www/