Classic exercises for computer vision / image processing?

For a mentoring projec开发者_如何学运维t, I am looking for an online repository of classic computer vision exercises, similar to Project Euler, but geared towards image processing problems that could be solved in MATLAB or OpenCV.

Anyone have any ideas?

Many computer vision university courses are online including their work assignments.
CVonline would be a good starting point.

There is no such a place for standard problems and test data for them in CV.

Here is one for Object Recognition.

I seem to remember hackthissite having a few image-related steganography challenges (the site is down atm).

Not exactly the classics (you might have to take a CV class for that), but definitely fun.