Here is an example of a problem that would be hard for computer to solve:

http://www.youtube.com/watch?v=4G4y79ZbaBs

How so? the fixed part can be easily extracted. If it also moved (while morphing) then I guess it would be hard, but fixed dots in a moving background would take just a few frames for a computer to solve.

You just diff each frame and keep the parts that don't change much. Very simple to solve.

Just move letters slightly. And make them morph a bit. Would still be obvious to a human, but a computer trying to average anything would fail miserably.

This is an unsolved computer vision problem.

which pixels stay black in all frames?