While Daniele's project might indeed be too complex for you, given your previous experience and the time window you have, you could still use the basic idea and start with simpler geometric shapes.
The "Image Processing Toolbox" for MATLAB is a great start, and I think Daniele made use of it. It can be used for rapid prototyping, and depending on how quick you can pick up new things, it might indeed be possible to get results very quickly. See here for tutorials, documentation, and so on
http://www.mathworks.com/products/image/
The robot construction Daniele chose is complex & advanced, too, when you want to model it (multiple coordinate transformations). Again, you can start "smaller", try something like a "car wash machine". We reguralily have students who succeed with this design. Here are some random pictures to illustrate what I mean:
If you find the image processing toolbox easy to use (I know I do), then you can use the free RWTH - Mindstorms NXT Toolbox to control your robot (preferrably via USB cable):
http://www.mindstorms.rwth-aachen.de