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Imagemaps

Imagemaps Defined

Imagemaps allow hyperlinks to different places from different parts of an image. They are especially great for accessing geographical information.

Server-side Imagemaps

The first imagemaps - The browser sends the coordinate that was clicked to the server and the server sends the browser to the corresponding URL. The method for use varies according to the type of server used.

Client-side Imagemaps

First implemented in html 3.2 - The URLs and associated coordinates are passed to the browser from the html document. Advantages:

• No communication with a server required; less work for the server
• No network traffic to resolve the URL
• Faster for the user
• New text-only browsers can resolve a client-side imagemap
• They are much easier to set up

Image Map Tools

• GeoHtml (Windows), free
• Mapedit (Windows, Mac, Unix using Java), $10

Client-side imagemaps should be used if at all possible. If server-side imagemaps must be used, equivalent text-only links should be provided.

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"Mastering a Web Site" online course Created and maintained by Lorna Schmid and David Boldt. http://water.usgs.gov/usgs/training/webmaster/image_maps.html     Last modified: Wed Nov 12 17:27:42 EST 2003