In a video conferencing setting, people often use an elongated meeting table with the major axis along the camera direction. A standard wide angle perspective image of this setting creates significant foreshortening, thus the people sitting at the far end of the table appear very small relative to those nearer the camera. This has two consequences. First, it is difficult for the remote participants to see the faces of those at the far end, thus affecting the experience of the video conferencing. Second, it is a waste of the screen space and network bandwidth because most of the pixels are used on the background instead of on the faces of the meeting participants. In this paper, we present a novel technique, called spatially-varying-uniform scaling functions, to warp the images to equalize the head sizes of the meeting participants without causing undue distortion. In addition, we show a specially designed five-lens camera to capture, stitch, and warp images in real time without sacrificing resolution. Finally, we show that the SVU scaling functions can also be applied to 360 degree images to improve video conferencing experience when an omni-directional camera is used.
['Zicheng Liu', 'Michael F. Cohen']
Head-size equalization for better visual perception of video conferencing