Adding Images to the wiki
To upload an image you use the "add to folder" drop down list (above right) to add an image file into the wiki directory structure. When you upload the file you will be asked to enter a short name. This is the name that will be used by the wiki to refer to this file so I suggest using the actual file name (including the extension).
The file will be added into your current directory (which you can check by looking at the navigation pane on the left).
If your wiki page is in the same directory you can use the img tag to place the uploaded image within the page. The src needs to use the short name of your image. For example I uploaded an image with the short name TruncatedCone, so using
<img src="TruncatedCone" />
Will produce the image like so:
<img src="TruncatedCone" />
You can also use an absolute link as the src
<img src="http://www.cmiss.org/cmgui/wiki/TruncatedCone" />