Inappropriate lighting is often responsible for poor quality video. In most offices and homes, lighting is not designed for video conferencing. This can result in unevenly lit faces, distracting shadows, and unnatural color effects. We present a method for relighting faces that reduces the effects of uneven lighting and color. Our setup consists of a compact lighting rig and a camera that is both inexpensive and inconspicuous to the user. We use unperceivable infrared (IR) lights to obtain an illumination basis space of the scene. Our algorithm computes an optimally weighted combination of infrared bases to minimize lighting inconsistencies in foreground areas. However, infrared relighting alone results in grayscale images with an unnatural ghostly appearance, thus an IR retargeting technique is presented which removes the unnatural IR appearance and produces videos that have substantially more balanced intensity and color than the original video.


Video Conferencing Relighting Using Infrared Illumination. [pdf]
Oliver Wang, James Davis, Erika Chuang, Ian Rickard, Krystle de Mesa, Chirag Dave.
Eurographics 2008. [bibtex]