System and method for image monitoring
An image monitoring system uses wireless communications to transmit images for security monitoring. The system includes a central controller ( 105 ) and a plurality of digital still camera units ( 110 ) operatively connected to the central controller ( 105 ). At least one of the camera units ( 110 ) includes an image sensor ( 215 ), a motion detector ( 220 ) that causes the image sensor ( 215 ) to receive image data when motion is detected, a micro controller ( 205 ), and a first nonvolatile memory operatively connected to or included in the micro controller ( 205 ). The micro controller ( 205 ) determines whether received image data should be transmitted to the central controller ( 105 ), and the central controller ( 105 ) determines whether received image data should be transmitted to a monitoring station ( 115 ). The camera units ( 110 ) may further be used as standalone units as replacements for motion detectors in existing security systems.
1. An image monitoring system comprising:
a central controller; and
a plurality of digital still camera units operatively connected to the central controller, wherein at least one of the camera units comprises
an image sensor;
a motion detector operatively connected to the image sensor that causes the image sensor to receive digital still image data when motion is detected;
a micro controller operatively connected to the image sensor and to the motion detector;
a first nonvolatile memory operatively connected to or included in the micro controller; and
computer readable program code stored on the first memory for causing the micro controller to determine whether the digital still image data should be transmitted to the central controller, wherein the central controller then determines whether the digital still image data should be transmitted to a monitoring station;
wherein at least one of the camera units includes a pre-trigger feature that, following a detection of motion by the motion detector, transmits to the central controller a series of buffered digital still images captured before the detection of motion.
2. The image monitoring system of claim 1 , wherein the plurality of camera units transmit the digital still image data wirelessly to the central controller.
3. The image monitoring system of claim 2 , wherein the central controller further comprises a mesh networking protocol enabling the digital still image data to be routed indirectly and wirelessly through one or more of the camera units to the central controller.
4. The image monitoring system of claim 1 , wherein at least one of the camera units further comprises a microphone.
5. The image monitoring system of claim 1 , wherein at least one of the camera units further comprises both a color image sensor and a black and white image sensor to improve low-light sensitivity, wherein both image sensors are operatively connected to a single high-speed DMA bus.
6. The image monitoring system of claim 1 , wherein at least one of the camera units is battery operated and comprises direct memory access circuitry between an image sensor and a second nonvolatile memory.
7. The image monitoring system of claim 1 , wherein the monitoring station forms a component of the image monitoring system, and wherein the monitoring station includes human personnel who further analyze the images to determine whether an alarm should be sent to an authority.
8. A method for image monitoring using a plurality of digital still camera units operatively connected to each other and to a central controller using wireless communications, the method comprising the steps of:
detecting motion of a moving object using a motion detector included in at least one of the camera units;
triggering the transmission of a series of digital still images from the memory buffer to a central controller following the detection of motion of the moving object, the series of digital still images including digital still images received before the detection of motion;
determining whether the series of digital still images should be transmitted wirelessly to the central controller by analyzing the series of digital still images using a micro controller included in at least one of the camera units and operatively connected to the image sensor;
determining whether a digital still image received at the central controller from said at least one of the camera units should be transmitted to a monitoring station;
wherein at least one of the camera units includes a pre-trigger feature including the steps of continuously receiving digital still images from the image sensor, storing the digital still images in a memory buffer of at least one camera units, and following a detection of motion by the motion detector, transmitting to the central controller a series of the digital still images received before the detection of motion.
9. The method for image monitoring of claim 8 , wherein the central controller further comprises a mesh networking protocol enabling image data to be routed indirectly and wirelessly through one or more of the camera units to the central controller.
10. The method for image monitoring of claim 8 , further comprising the step of storing images received by the image sensor in a memory unit of a camera unit using direct memory access.
11. The method for image monitoring of claim 10 , wherein the step of triggering an image sensor comprises triggering a black and white image sensor in low light conditions, and otherwise triggering a color image sensor, wherein at least one camera unit includes both the color image sensor and the black and white image sensor operatively connected to a single high-speed DMA bus.