[StavrosK]

Wouldn't it be "easy" to capture a video of a minute or so and then write an algorithm to keep the parts that were unchanged among all frames? I did something like that ten years or so ago, and it worked very well (it took the mode of each pixel among X frames).

[alephnil]

In many cases that will do, but there will be problem with continuously changing objects, such as ads, escalators and clocks that will be blurred, at least unless a quite sophisticated algorithm is used.

[nickthemagicman]

I know. Why didn't he just write a movement recognition algorithm and run his videos through it. It only has to be one frame really.