Network camera having network failure recovery
A network camera 1 comprises a camera block 10 for taking an image, a signal processing unit 20 supplied with an imaging output of the camera block 10 , a communication interface unit 30 which connects to an external network to establish communication, a backup memory unit 40 which temporarily stores data to be transmitted to an external device via the communication interface unit 30 , a system control unit 50 which controls the above components, and the like. The system control unit 50 monitors the state of the network and stores temporarily the compressed image data to be transmitted to the server in the backup memory unit 40 when a failure occurs in the network, and controls transmission processing such that the compressed image data that has been stored in the backup memory unit 40 is transmitted to the server after the network has recovered.
1. A network camera configured to transmit image data in real time to a server connected thereto via a network comprising:
a single imaging means;
data compression means for converting the image data obtained by the single imaging means into compressed image data;
network interface means for communicating with the server via the network;
control means for controlling transmission processing and setting a transmission interval having a first delay interval of a first predetermined length of time and setting a second delay interval of a second predetermined length of time, such that the compressed image data obtained by the data compression means is transmitted to the server via the network interface means during the first delay interval, the transmission interval being the sum of the first delay interval followed sequentially by the second delay interval; and
data store means for storing, during the first delay interval, the compressed image data to be transmitted to the server when a failure occurs in the network and the compressed image data cannot be transferred in real time to the server,
wherein the control means that monitors the state of the network stores the compressed image data to be transmitted to the server in the data store means only when a failure occurs in the network,
wherein, upon recovery of the network, the control means controls transmission processing such that only the compressed image data that has been stored in the data store means is transmitted to the server during the second delay interval, and
wherein the second delay interval is set equal to the first delay interval when image data exists in the data store.
2. The network camera according to claim 1 , wherein the transmission interval at which the compressed image data is transmitted to the server via the network interface means is made variable, and the control means controls transmission processing such that the compressed image data that has been stored in the data store means is transmitted at a transmission interval shorter than a normal transmission interval at the time of recovery of the network.
3. The network camera according to claim 1 , wherein there is a transmission period during which image data is transmitted in real time and a transmission break period during which image data is not transmitted in real-time, and wherein the control means controls transmission processing such that, when compressed image data exists in the data store means, the stored image data is transmitted during the transmission break period.
4. The network camera according to claim 1 , wherein the control means switch between;
a first control mode in which the transmission interval at which the compressed image data is transmitted to the server via the network interface means is made variable and the compressed image data that has been stored in the data store means is transmitted at a transmission interval shorter than a normal transmission interval at the time of recovery of the network; and
a second control mode in which there is a transmission period during which image data is transmitted in real time and a transmission break period during which image data is not transmitted in real-time, and wherein the control means controls transmission processing such that, when compressed image data exists in the data store means, the stored image data is transmitted during the transmission break period.