If you are interested in artificial vision, mayby you could take topics that are connected with damage recognisation. It's interesting thesis for many of producting companies and also it's not so difficult (simple camera, controler of vision systems with usage of their main function and you can avoid very spectaculary effects, for example in connected with conveyor belt you can choose wrong part with damages and put they to special pile). Do you have mayby acces to some kind of artificial vision laboratory?