1. A method of generating stereoscopic images, comprising: capturing stereo images that are video images of a head and, optionally, a torso by a stereoscopic pair of cameras; in each of the stereo images, segmenting the head and, if present, the torso from the backgrounds, thereby producing segmented backgrounds; and in each of the stereo images, replacing the segmented backgrounds by respective replacement images that have a degree of perceived stereoscopic depth within the replacement images that is lower than a degree of perceived stereoscopic depth within the original backgrounds.