Automatic detection and prioritized image transmission system and method

• US 5,521,634 A
• Filed: 06/17/1994
• Issued: 05/28/1996
• Est. Priority Date: 06/17/1994
• Status: Expired due to Term

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: McGary, Doug
• Primary Examiner(s): Chin, Tommy P.
• Assistant Examiner(s): RAO, ANAND SHASHIKANT
• Application Number:
  US08/261,979
• Time in Patent Office: 711 Days
• Field of Search: 348/169, 348/170, 348/142, 348/143, 348/152, 348/153, 348/154, 348/155, 348/162, 348/163, 348/164
• US Class Current: 348/169
• CPC Class Codes: G01S 3/7864 T.V. type tracking systems
• CPC Class Codes: G06F 18/256 of results relating to different input data, e.g. multimodal recognition
• CPC Class Codes: G06V 10/255 Detecting or recognising potential candidate objects based on visual cues, e.g. shapes
• CPC Class Codes: G06V 10/811 the classifiers operating on different input data, e.g. multi-modal recognition
• CPC Class Codes: G08B 13/19608 Tracking movement of a target, e.g. by detecting an object predefined as a target, using target direction and or velocity to predict its new position
• CPC Class Codes: G08B 13/19667 Details realated to data compression, encryption or encoding, e.g. resolution modes for reducing data volume to lower transmission bandwidth or memory requirements
• CPC Class Codes: G08B 13/19695 Arrangements wherein non-video detectors start video recording or forwarding but do not generate an alarm themselves
• CPC Class Codes: H04N 7/18 Closed-circuit television [CCTV] systems, i.e. systems in which the video signal is not broadcast

Abstract

An image transmission system and method automatically reduce the size of digital data signals transmitted from visual sensors. The system and method are completely automated and (a) use a plurality of sensors to detect targets in an area of interest, (b) direct a camera to place a target in the camera'"'"'s field of view, (c) provide a digitized visual image in which the target is identified in a target box, and (d) automatically compress (or otherwise reduce the size of) a digital signal for nontarget portions of the visual image.

Claims

1. A video image compression system for automatically detecting a target in an area of interest and transmitting a digital image of the target wherein a digital image of nontarget information in the area of interest is automatically reduced in size before transmission thereof comprising:

a target detector for searching an area of interest, said target detector detecting at least one of an acoustic, seismic, infrared, electromagnetic, trip-wire, and visual signal related to potential targets;

a system controller for evaluating whether a signal from potential targets detected by said target detector is related to a target, said system controller comprising,

i) means for evaluating signals from potential targets to determine whether such signals identify a target,

ii) means for determining a direction to an identified target,

iii) means for using the determined direction to establish a target box within which the identified target is located, and

iv) means for following target movement and retaining the target in said target box;

a camera system that receives commands from said system controller for moving said camera system to said target box so that said camera system has said target box in a field of view, said camera system comprising,

i) means for automatically adjusting the field of view and focus of said camera system so that an image of said target box and a portion of an adjacent area of interest can be generated by said camera system, and

ii) means for generating a digital signal representing said target box and said adjacent area of interest;

said system controller further comprising,

v) means for reducing the size of said digital signal of the adjacent area of interest that is to be transmitted,

vi) means for providing instructions for moving said camera system as said target box moves so that said target box is maintained in said camera system field of view, and

vii) means for designating a new adjacent area of interest uncovered by movement of said target box for transmission; and

means for transmitting on a radio frequency said digital signal of said target box and said reduced size digital signal of said adjacent area of interest.

2. The image compression system of claim 1 wherein said means for reducing the size of said digital signal comprises means for transmitting said digital signal of said adjacent area of interest periodically.

3. The image compression system of claim 1 wherein said means for reducing the size of said digital signal comprises means for transmitting said digital signal of said adjacent area of interest when it first appears in said camera system field of view and not thereafter.

4. The image compression system of claim 1 wherein said means for following target movement comprises means for evaluating a periodicity of moving portions of the digital image.

5. The image compression system of claim 1 further comprising means for compressing said digital signal representing said target box.

6. The image compression system of claim 1 wherein said target detector comprises an acoustic sensor and an infrared sensor.

7. The image compression system of claim 6 wherein said camera system comprises a video camera, and wherein said means for evaluating potential targets comprises means for evaluating signals from said video camera, said acoustic sensor and said infrared sensor.

8. A method of automatically detecting a target in an area of interest and transmitting a digital image of the target wherein a digital image of nontarget information in the area of interest is reduced in size before transmission thereof, the method comprising the steps of:

a) searching an area of interest with an automated target detector, the target detector detecting at least one of an acoustic, seismic, infrared, electromagnetic, trip-wire, and visual signal related to a potential target;

b) upon detection of signal related to a potential target by the target detector, evaluating the detected signal in a system controller to determine whether the potential target is a target;

c) upon determination that the potential target is a target, determining in the system controller a direction to the target;

d) the system controller using the determined direction to establish a target box within which the target is located and thereafter retained by following target movement;

e) providing a signal from the system controller to a camera system for moving the camera system so that the camera system has the target box in the camera system field of view;

f) automatically adjusting the field of view and focus of the camera system so that an image of the target box and a portion of an adjacent area of interest may be generated by the camera system;

g) generating a digital signal of the image of the target box and adjacent area of interest with the camera system;

h) reducing the size of the digital signal of the adjacent area of interest;

i) transmitting the digital signal of the target box and the reduced size signal of the adjacent area of interest;

j) providing signals from the system controller for moving the field of view of the camera system as the target box moves so that the target box is maintained in the camera system field of view; and

k) transmitting the digital signal of a new adjacent area of interest uncovered by the movement of the target box.

9. The method of claim 8 wherein multiple targets are detected and separate target boxes are established for each of the multiple targets.

10. The method of claim 8 wherein the digital signal of the adjacent area of interest is transmitted periodically.

11. The method of claim 8 wherein the digital signal of the adjacent area of interest is transmitted only the first time it appears in the camera system field of view.

12. The method of claim 8 wherein when movement of the target box uncovers a new adjacent area of interest, the digital signal of the uncovered adjacent area of interest is transmitted immediately.

13. The method of claim 8 wherein the digital signal of the adjacent area of interest is compressed to a predetermined first level.

14. The method of claim 8 wherein the digital signal of the adjacent area of interest is transmitted only when a new adjacent area is required because of target movement.

15. The method of claim 13 wherein the digital image of the target box is compressed to a second level less than the first level.