摘要 |
A remote surveillance system has a video camera connected (101) to a public communications network (202) such as the public switched telephone (PSTN), and a viewing station (205, 206), such as a personal computer, connected to the network. The viewing station establishes a call to the camera and makes a request for compressed image frames. The video camera answers the call and transmits compressed image frames to the viewing station. The viewing station receives the compressed frames from the camera and decompresses the frames so as to produce viewable images. In this way, a relatively low cost surveillance system is provided while making optimum use of the available transmission bandwidth. |