Bi-level/full-color video combination for ubiquitous video communication
Keman Yu, Jiang Li, Shipeng Li · 2003
Ubiquitous video communication, visually calling anyone at anywhere anytime on any device might be the ultimate goal of modem communication service. As MPEG and H.263 based full-color videos are unable to cover low bandwidth network conditions, we have developed a bi-level/full-color video combination scheme to realize video communication in the whole range of bandwidth conditions. In our scheme, bi-level video works at below 56 Kbps bandwidth range and full-color video works at over 33.6 Kbps bandwidth range. The overlapped bandwidth range 33.6-56 Kbps is used to smoothly switch between bi-level and full-color videos. A bandwidth estimation algorithm is applied to normal bi-level or full-color video status for rate control. A special bandwidth capability probing algorithm is designed to determine the switch of bi-level and full-color videos. Experiments showed that this scheme worked well on video communication systems that ran on PCs, handheld PCs and palm-size PCs.