In video processing, deflicking is a filtering operation applied to brightness. It aims to improve the visual quality of the video. The flicker effect can be seen when the camera framerate and lighting frequency are not in synch. Flickering can also occur when old films are digitized.
The main idea is to smooth image brightness between series of the same scene frames.
The deflicking filter is usually used in video camera (for normalizing picture), used for postprocessing of captured video, and for the restoration of video from old films.