Noise Reduction

    At many stages of the film-to-video process, noise reduction can be applied, for a variety of reasons. It is commonly applied to make the job of MPEG compression easier - a less noisy image can be better compressed than a noisy image, since randomness is removed from the image being encoded. The excessive use of noise reduction can manifest as an image which displays the disconcerting and annoying phenomenon of parts of the image moving independently of each other. Often this can affect faces, making them appear to float independently of the rest of an image.
 

Phenomenon 55:57-55:58
Note the back of the chair, particularly against the white sliver of window, moving independently of the rest of the image.