| 摘要 |
<p>A video communication system has an encoder (250) arranged to encode a digital video image signal at different quantisation levels. A segmentation arrangement (220) of the system divides the digital video signal into first and second image segments. Encoding means identifies INTRA coded frames, and for such frames encodes the first image segment at a low quantisation level and the second image segment at a high quantisation level. In this way, the first and the second segments may be transmitted over a network as a single encoded signal (260) having both low and high quantisation levels. The first image segment provides a high spatial resolution for objects of interest to a user, coupled with a quick first image display time. Therefore, there is a significant reduction in the transmission time without sacrificing the spatial image resolution of the object(s) of interest. The invention may comprise part of a security camera, or a mobile radio unit, such as a mobile phone, a portable or mobile PMR radio, a personal digital assistant, a laptop computer or a wirelessly networked PC. <IMAGE></p> |
