Electro-optical foveated imaging and tracking system

• US 7,973,834 B2
• Filed: 09/24/2007
• Issued: 07/05/2011
• Est. Priority Date: 09/24/2007
• Status: Expired due to Fees

• Current Assignee: Jianwen Yang
• Original Assignee: Jianwen Yang
• Inventors: Yang, Jianwen
• Primary Examiner(s): PERUNGAVOOR, SATHYANARAYA V
• Application Number:
  US11/860,040
• Publication Number:
  US 20090080695A1
• Time in Patent Office: 1,380 Days
• Field of Search: 348/240.3
• US Class Current: 348/240.3
• CPC Class Codes: G06V 10/255 Detecting or recognising potential candidate objects based on visual cues, e.g. shapes
• CPC Class Codes: G06V 10/92 using spatial domain filters, e.g. joint transform correlators

Abstract

Conventional electro-optical imaging systems can not achieve wide field of view (FOV) and high spatial resolution imaging simultaneously due to format size limitations of image sensor arrays. To implement wide field of regard imaging with high resolution, mechanical scanning mechanisms are typically used. Still, sensor data processing and communication speed is constrained due to large amount of data if large format image sensor arrays are used. This invention describes an electro-optical imaging system that achieves wide FOV global imaging for suspect object detection and local high resolution for object recognition and tracking. It mimics foveated imaging property of human eyes. There is no mechanical scanning for changing the region of interest (ROI). Two relatively small format image sensor arrays are used to respectively acquire global low resolution image and local high resolution image. The ROI is detected and located by analysis of the global image. A lens array along with an electronically addressed switch array and a magnification lens is used to pick out and magnify the local image. The global image and local image are processed by the processor, and can be fused for display. Three embodiments of the invention are described.

Claims

1. An electro-optical foveated imaging and tracking system comprising:

a lens;

an image transfer device configured to receive an image from the lens;

a readout of the image transfer device using a collimated visible light beam;

a device configured to generate two image relay channels using the readout;

a first image detection device with an image magnifying subsystem configured to receive one of the two image relay channels;

a second image detection device configured to receive the other one of the two image relay channels;

a switcher array configured to transmit a sub-region of one of the two image relay channels onto the first image detection device; and

a processor configured to receive data from the first and second image detection devices and perform processing.

2. The electro-optical foveated imaging and tracking system according to claim 1, wherein the lens includes at least one of refractive or reflective components.

3. The electro-optical foveated imaging and tracking system according to claim 1,

wherein a scene is imaged at a designated waveband;

and

wherein the image transfer device makes a visible copy for readout.

4. The electro-optical foveated imaging and tracking system according to claim 1, wherein the collimated visible light beam is generated using at least a spot white light source, a collimation lens and a beam splitter.

5. The electro-optical foveated imaging and tracking system according to claim 1, further comprising an optical configuration with the lens being common and a beam splitter located at focal plane to generate the two image relay channels.

6. The electro-optical foveated imaging and tracking system according to claim 1, wherein the magnifying subsystem includes at least one of a lens array and a magnification lens.

7. The electro-optical foveated imaging and tracking system according to claim 1, wherein the switcher array is addressable by an electronic signal to open a specified unit that is relevant to a region of interest (ROI) location.

8. The electro-optical foveated imaging and tracking system according to claim 1, wherein the first image detection device is located on a back focal plane of a magnification lens in order to acquire a local magnified image and the second image detection device is located at a relayed image location in order to acquire the global image.

9. The electro-optical foveated imaging and tracking system according to claim 8, wherein the global image is analyzed and processed by the processor and a region of interest (ROI) in the global scene is determined by the processor or by direct human eye monitoring.

10. The electro-optical foveated imaging and tracking system according to claim 9, wherein a location information of region of interest (ROI) is sent to the switcher array to open a corresponding unit.

11. The electro-optical foveated imaging and tracking system according to claim 1, wherein the processor further includes a computing system with programs to perform at least one of image processing and automatic target detection.

12. The electro-optical foveated imaging and tracking system according to claim 1, further comprising a display configured to display an acquired global image and local image and a operator interface configured for pointing to a region of interest on the global image.

13. An electro-optical foveated imaging and tracking system comprising:

a lens;

an image splitting device to split the image obtained from the lens into two image relay channels;

a first image detection device with an image magnifying subsystem configured to receive one of the two image relay channels;

a second image detection device configured to receive the other one of the two image relay channels;

a switcher array configured to transmit a sub-region of one of the two image relay channels onto the first image detection device; and

a processor configured to receive data from the first and second image detection devices and perform processing.

14. The electro-optical foveated imaging and tracking system according to claim 13, wherein the lens includes at least one of refractive or reflective components.

15. The electro-optical foveated imaging and tracking system according to claim 13, wherein the two image relay channels comprises one channel for global imaging and the other for local magnification.

16. The electro-optical foveated imaging and tracking system according to claim 13, wherein the magnifying subsystem includes at least one of a lens array and a magnification lens.

17. The electro-optical foveated imaging and tracking system according to claim 13, wherein the switcher array is addressable by an electronic signal to open a specified unit that is relevant to a region of interest (ROI) location.

18. The electro-optical foveated imaging and tracking system according to claim 13, wherein the first image detection device is located on a back focal plane of a magnification lens in order to acquire a local magnified image and the second image detection device is located at a location of a transmitted image of the image splitting device in order to acquire the global image.

19. The electro-optical foveated imaging and tracking system according to claim 18, wherein the global image is analyzed and processed by the processor and a region of interest (ROI) in the global scene is determined by the processor or by direct human eye monitoring.

20. The electro-optical foveated imaging and tracking system according to claim 19, wherein a location information of region of interest (ROI) is sent to the switcher array to open a corresponding unit.

21. The electro-optical foveated imaging and tracking system according to claim 13, wherein the processor further includes a computing system with programs to perform at least one of image processing and automatic target detection.

22. The electro-optical foveated imaging and tracking system according to claim 13, further comprising a display configured to display an acquired global image and local image and operator interface configured for pointing to a region of interest on the global image.

23. An electro-optical foveated imaging and tracking system comprising:

a lens;

a micro-mirrors array device configured to receive an image from the lens and output two image relay channels;

a first image detection device with an image magnifying subsystem configured to receive one of the two image relay channels;

a second image detection device configured to receive the other one of the two image relay channels;

a switcher array configured to transmit a sub-region of one of the two image relay channels onto the first image detection device; and

a processor configured to receive data from the first and second image detection devices and perform processing.

24. The electro-optical foveated imaging and tracking system according to claim 23, wherein the lens includes at least one of refractive or reflective components.

25. The electro-optical foveated imaging and tracking system according to claim 23, wherein the micro-mirrors array device selects and redirects the selected portion of an image acquired by the lens as the two image relay channels, with one channel being for global imaging and the other channel being for local magnification.

26. The electro-optical foveated imaging and tracking system according to claim 23, further comprising at least one of an aspherical mirror and refractive lens to relay the selected portion of the image on the micro-mirrors array device.

27. The electro-optical foveated imaging and tracking system according to claim 23, wherein the magnifying subsystem includes at least one of a lens array and a magnification lens.

28. The electro-optical foveated imaging and tracking system according to claim 23, wherein the switcher array is addressable by an electronic signal to open a specified unit that is relevant to a region of interest (ROI) location.

29. The electro-optical foveated imaging and tracking system according to claim 23, wherein the first image detection device is located on a back focal plane of the magnification lens in order to acquire a local magnified image and the second image detection device is located at a relayed image location in order to acquire the global image.

30. The electro-optical foveated imaging and tracking system according to claim 29, wherein the global image is analyzed and processed by the processor and a region of interest (ROI) in the global scene is determined by the processor or by direct human eye monitoring.

31. The electro-optical foveated imaging and tracking system according to claim 30, wherein a location information of region of interest (ROI) is sent to the switcher array to open a corresponding unit.

32. The electro-optical foveated imaging and tracking system according to claim 23, wherein the processor further includes a computing system with programs to perform at least one of image processing and automatic target detection.

33. The electro-optical foveated imaging and tracking system according to claim 23, further comprising a display configured to display an acquired global image and local image and operator interface configured for pointing to the region of interest on the global image.