Hi it shoudl be greaet if you can include something to create a sketchpad for makeing basic drawings over ana already TIWImage or any other region.
Something seen in demos from JQuery SVG (http://keith-wood.name/svg.html) Sketpacth demo,
Paperjs (http://paperjs.org/tutorials/interaction/creating-mouse-tools/#click-drag-release) or
raphaeljs (http://raphaeljs.com/)
There is beta version demo in uniGUI (http://www.unigui.com/demo) 'Canvas' that approaches something http://prime.fmsoft.net/demo/canvas.dll
Also check: http://kineticjs.com/
Maybe not such fancy as them, but being able to have a basic canvas with predefined shapes to create drawings with their specific property like With, color, brush and pen. maybe also this canvas can be drawe over an existing TIWImage or other TIWControl.
Regards