TITLE: How to un-pixelate pixelated regions in films?
QUESTION [11 upvotes]: Everybody knows the effect of pixelated objects (e.g. faces) on TV. Is there a way - and which mathematical method lies behind it - to un-pixelate the region? Beware: I am not talking about smoothing it out (unblur) image by image - but about using the information of a whole sequence of pixelated pictures where the object which is pixelated naturally changes the location within the overall pixelated region. I guess it must be some kind of "un-averaging over time" (e.g. differentiation over time comes into mind).
Has anybody tackled this problem yet? Are there references, demos, software...?
Thank you.

REPLY [14 votes]: This is a problem that has been addressed by the computer vision community in the past few years. You may want to look into upsampling and super-resolution techniques as well as vectorization methods. Here is a recent paper on the topic in ICCV 2009 which gives a good summary of the recent efforts in this field: http://www.wisdom.weizmann.ac.il/~vision/SingleImageSR.html