June 3, 1999
Image maps can be confusing for novice Web surfers. Many users don't
realize that certain parts of an image map can be clickable while
others are not. The WebTV browser, on the other hand, seamlessly integrates
image maps into the page navigation so image hotspots appear as regular
links. However, certain types of image maps don't integrate well and
can appear cumbersome with a WebTV browser. A moment or two spent
analyzing your image maps will ensure that WebTV-based users can easily
navigate your site.
If you're not familiar with the WebTV browser "selection box",
read about how WebTV-based users navigate
How Image Maps Appear With the WebTV Browser
While all image maps might look identical to computer users, Web designers
know that there are different ways to implement an image map; the WebTV
browser can react differently to those implementations.
When discussing the WebTV browser, there are three types of image maps to consider:
Note - Behavior of <input type=image>
Image maps can also be part of forms - by using the <input type=image> tag. When the image is clicked, this tag passes along to the server the x and y coordinates of that click. However, pages that use this tag rarely use it for image maps - most use it to create a graphical submit button on the form.
The WebTV browser has no sure way of knowing if the image is being used as a graphical submit button or as an image map, and optimal behavior is different for each. To approximate authors' intent, the WebTV browser will act differently according to the size of the image. Images larger than 97 by 65 pixels are assumed to be image maps; WebTV users are then prompted with the "two-click cursor" as in the example above. Images smaller than 97 by 65 pixels are assumed to be graphical submit buttons; the user is not presented with any way to select different parts of the image, only the image as a whole.