Methods, systems and computer program products, for producing streams of image frames. Image frames in streaming video are segmented into background segments and instance segments. A background image frame containing the background segments is created. At least some of the instance segments are classified into movable objects of interest and movable objects of non-interest. During a background update time period, the background image frame is updated when a movable object of non-interest has moved to reveal a background area, to include the revealed background area in the background image frame. A foreground image containing the movable objects of interest is created. Blocks of pixels of the updated background and foreground image frames are encoded. A stream of encoded foreground image frames having a first frame rate is produced. A stream of encoded updated background image frames a second, lower frame rate is produced.