Several browsers support the attributes WIDTH and
HEIGHT for tags like <IMG>. If you know the
exact with of your image, you can tell it the browser. This might
speed up the layout-engine, because the browser doesn't have to
wait for the image to be transfered or needs to relayout the page
after the transfer
As you usually don't know the exact size of your images, let your stupid computer handle that tricky task by enabling the switch GETSIZE when invoking hsc
Supported image formats are GIF, JFIF/JPEG and PNG.