Hmm, I guess my recommendation, if you want an image instead of a title would be to use the standard text box, use your image in the text-field area and leave the widget title field blank.
Your widget will have no title this way but the content will contain the image, along with anything else you wan’t to follow it.
If you want to use an image with a specific widget, and it must be the title, that is more of a WordPress (not Criss Cross) customization. Try this article: Image Title Replacement for WordPress Widgets.
Hope this helps.