Wide area imaging system and method
The present invention provides a new and useful paradigm in wide area imaging, in which wide area imaging is provided by a step/dwell/image capture process and system to capture images and produce from the captured images a wide area image. The image capture is by a sensor that has a predetermined image field and provides image capture at a predetermined frame capture rate, and by a motorized step and dwell sequence of the sensor, where image capture is during a dwell, and the step and dwell sequence of the sensor is synchronized with the image capture rate of the sensor.
1. A wide area imaging system for performing surveillance of an area, the system comprising:
a sensor that uses a rotational step/dwell/image capture sequence to capture images of the area under surveillance, the sensor providing image capture of a predetermined image field; and
a processor that controls the step/dwell/image capture sequence to synchronize motion in a direction of rotation of the system with image capture, wherein the predetermined image field advances in the direction of rotation as the system rotates, and wherein the captured images are used to produce a wide-area image of the area under surveillance, the processor being configured to operate in a first mode and a second mode,
in the first mode, the processor controlling the sensor to capture a first set of images of the area under surveillance, the first set of images being used to produce a first wide-area image of the area under surveillance, the first wide-area image having a first resolution, and
in the second mode, the processor controlling the sensor to capture a subsequent second set of images of the area under surveillance, the second set of images being used to produce a subsequent second wide-area image of the area under surveillance, at least a portion of the second wide-area image having a second resolution that is higher than the first resolution,
wherein the processor is configured to operate in the second mode in response to detection, by the processor, of one or more objects of interest in the first wide-area image, and
wherein the system is configured to store image data produced from the step/dwell/image capture sequence, and to use the stored image data as a reference for comparison with image data produced from a subsequent step/dwell/image capture sequence.
2. The wide area imaging system of claim 1 , wherein the first wide-area image covers a larger region of the area under surveillance than the second wide-area image.
3. The wide area imaging system of claim 1 , wherein the sensor is configured to measure a physical temperature of one or more objects in the area under surveillance.
4. The wide area imaging system of claim 3 , wherein the processor is configured to utilize the measured physical temperature from the sensor to determine the presence of fire in the area under surveillance.
5. The wide area imaging system of claim 1 , wherein the processor is configured to detect thermal abnormalities in the area under surveillance.
6. The wide area imaging system of claim 1 , wherein the sensor is located on a moveable platform, and one or more inertial devices measure movements of the platform that affect the wide-area image produced from the captured images and produce output that can be used to provide image compensation that is related to such movements of the platform.
7. The wide area imaging system of claim 1 , wherein the processor uses object detection on the wide-area image or the captured images to extract and localize objects of interest in the wide-area image.
8. The wide area imaging system of claim 1 , wherein the processor is configured to use successive hypothesis testing of detected objects in the wide-area image to determine the step and dwell sequences of the sensor.
9. The wide area imaging system of claim 1 , wherein the processor uses object tracking on the wide-area image or the captured images to record the behavior of one or more objects of interest in one or more wide-area images.
10. A wide area imaging method for performing surveillance of an area, the method comprising:
operating a sensor that uses a rotational step/dwell/image capture sequence to capture images of the area under surveillance, the sensor providing image capture of a predetermined image field;
controlling, by a processor, the step/dwell/image capture sequence to synchronize motion in a direction of rotation of the system with image capture, wherein the predetermined image field advances in the direction of rotation as the system rotates;
using the captured images to produce a wide-area image of the area under surveillance;
operating the processor in a first mode, wherein the processor controls the sensor to capture a first set of images of the area under surveillance, the first set of images being used to produce a first wide-area image of the area under surveillance, the first wide-area image having a first resolution;
operating the processor in a second mode, in response to detection, by the processor, of one or more objects of interest in the first wide-area image, wherein in the second mode the processor controls the sensor to capture a subsequent second set of images of the area under surveillance, the second set of images being used to produce a subsequent second wide-area image of the area under surveillance, at least a portion of the second wide-area image having a second resolution that is higher than the first resolution;
storing image data produced from the step/dwell/image capture sequence; and
using the stored image data as a reference for comparison with image data produced from a subsequent step/dwell/image capture sequence.
11. The wide area imaging method of claim 10 , wherein the first wide-area image covers a larger region of the area under surveillance than the second wide-area image.
12. The wide area imaging method of claim 10 , further comprising measuring, by the sensor, a physical temperature of one or more objects in the area under surveillance.
13. The wide area imaging method of claim 12 , further comprising determining, by the processor utilizing the measured physical temperature from the sensor, the presence of fire in the area under surveillance.
14. The wide area imaging method of claim 10 , further comprising detecting, by the processor, thermal abnormalities in the area under surveillance.
15. The wide area imaging method of claim 10 , further comprising extracting and localizing, by the processor using object detection on the wide-area image or the captured images, objects of interest in the wide-area image.
16. The wide area imaging method of claim 10 , further comprising determining, by the processor using successive hypothesis testing of detected objects in the wide-area image, the step and dwell sequences of the sensor.
17. The wide area imaging method of claim 10 , further comprising recording, by the processor using object tracking on the wide-area image or the captured images, the behavior of one or more objects of interest in one or more wide-area images.