Abstract: An internet user visits a web site and requests to see imagery from a specified one of a plurality of video cameras. At a system associated with the web site, a load distribution server assigns the user's request to one of a plurality of image servers. The assigned image server first checks its local image cache to see whether a recent image from the specified camera is stored there. If so, the image from that local image cache is sent to the user. If the local image cache does not have a recent image from the requested camera, the assigned image server then checks its local request cache to see whether an earlier process has recently requested the same imagery. If so, then the assigned image server simply waits for the earlier process to compete instead of initiating its own new image retrieval request. If no earlier process has recently requested the same imagery, the assigned image server issues its own image retrieval request.

Abstract: A method and system for monitoring the quality of video cameras automatically performs one or more tests on a current image received from each of the cameras. The cameras are connected to a network, such as the Internet, and are generally of different types and are owned and/or operated by various entities. A current image from each of the cameras is evaluated using image processing techniques so that a human need not have to view the camera imagery when an initial evaluation is made. Evaluation parameters may include such things as whether a camera is outputting a predefined error image, an image whose brightness is bad, or an image with bad hues. The status of each camera on a network is stored along with a snapshot of the image from which an evaluation was made and a time stamp. The data are made available to the operator of the camera for maintenance and other purposes.

Abstract: An internet user visits a web site and requests to see imagery from a specified one of a plurality of video cameras. At a system associated with the web site, a load distribution server assigns the user's request to one of a plurality of image servers. The assigned image server first checks its local image cache to see whether a recent image from the specified camera is stored there. If so, the image from that local image cache is sent to the user. If the local image cache does not have a recent image from the requested camera, the assigned image server then checks its local request cache to see whether an earlier process has recently requested the same imagery. If so, then the assigned image server simply waits for the earlier process to compete instead of initiating its own new image retrieval request. If no earlier process has recently requested the same imagery, the assigned image server issues its own image retrieval request.