OMNIDIRECTIONAL IMAGING OPTICS WITH 360º-SEAMLESS TELESCOPIC RESOLUTION

• US 20110221767A1
• Filed: 08/30/2010
• Published: 09/15/2011
• Est. Priority Date: 03/09/2010
• Status: Active Grant

• Current Assignee: Mercury Mission Systems LLC (Mercury Systems, Incorporated)
• Original Assignee: Physical Optics Corporation
• Inventors: KIM, NATHANAEL KEEHOON, PRADHAN, RANJIT, JANNSON, TOMASZ, WANG, WENJIAN, KOSTRZEWSKI, ANDREW
• Granted Patent: US 8,743,199 B2
• Time in Patent Office: Days
• US Class Current: 345/629
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 17/06 using mirrors only , i.e. having only one curved mirror used in non-imaging applications G02B19/00
• CPC Class Codes: G02B 5/09 Multifaceted or polygonal mirrors , e.g. polygonal scanning mirrors; Fresnel mirrors
• CPC Class Codes: G09G 2340/045 Zooming at least part of an image, i.e. enlarging it or shrinking it
• CPC Class Codes: H04N 23/00 Cameras or camera modules comprising electronic image sensors; Control thereof
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

A multifacet mirror comprises a catoptric structure configured to reflect light from a first field of view onto an image plane comprising a plurality of sensors, the catoptric structure having a surface comprising a plurality of facets separated by a plurality of catoptric regions; wherein a facet of the plurality of the facets has a second field of view that is smaller than the predetermined field of view; and wherein a catoptric region of the plurality or catoptric regions between two facets of the plurality of facets is configured to reflect light from a world point within the first field of view onto two of the sensors of the plurality of sensors.

Claims

1. An apparatus, comprising:

a catoptric structure configured to reflect light from a first field of view onto an image plane comprising a plurality of sensors, the catoptric structure having a surface comprising a plurality of facets separated by a plurality of catoptric regions;

wherein a facet of the plurality of the facets has a second field of view that is smaller than the predetermined field of view; and

wherein a catoptric region of the plurality of catoptric regions between two facets of the plurality of facets is configured to reflect light from a world point within the first field of view onto two of the sensors of the plurality of sensors.

2. The apparatus of claim 1, wherein the catoptric region between the two facets is configured to reflect light from the world point within the field of view onto neighboring edge regions of the two sensors.

3. The apparatus of claim 2, wherein each facet of the plurality of facets has an effective viewpoint, and wherein each image of the viewpoints of the plurality of facets are imaged onto a separate sensors of the plurality of sensors.

4. The apparatus of claim 2, wherein each facet of the plurality of facets has an effective viewpoint, and wherein the effective viewpoints of the plurality of facets coincide at a focal plane of the catoptric structure.

5. The apparatus of claim 2, wherein each facet of the plurality of facets has an effective viewpoint, and wherein the effective viewpoints of the plurality of facets do not coincide at a focal plane of the catoptric structure.

6. The apparatus of claim 2, wherein:

the first field of view has a first azimuthal component and a first horizontal component;

the second field of view has a second azimuthal component that is substantially the same as the first azimuthal component; and

the second field of view has a second horizontal component that is smaller than the first horizontal component.

7. The apparatus of claim 6, wherein a facet of the plurality of facets has a surface profile comprising a portion of a surface of revolution of a skewed or unskewed conic section from a first angle to a second angle.

8. The apparatus of claim 7, wherein the angular distance between the first angle and the second angle determines the width of edge regions of the two sensors.

9. The apparatus of claim 7, wherein the angular distance between the first angle and the second angle is

10. The apparatus of claim 7, wherein the conic section is a hyperbola.

11. The apparatus of claim 2, wherein:

the first field of view as a first azimuthal component and a first horizontal component;

the second field of view has a second azimuthal component that is smaller than the first azimuthal component; and

the second field of view has a second horizontal component that is smaller than the first horizontal component.

12. A catadioptric imaging system, comprising:

a catoptric structure configured to reflect light from a first field of view onto an image plane comprising a plurality of sensors, the catoptric structure having, a surface comprising a plurality of facets separated by a plurality of catoptric regions,

wherein a facet of the plurality of the facets has a second field of view that is smaller than the predetermined field of view, and

wherein a catoptric region of the plurality of catoptric regions between two facets of the plurality of facets is configured to reflect light from a world point within the first field of view onto two of the sensors of the plurality of sensors;

a lens at a focal plane of the catoptric structure; and

the plurality of sensor at the image plane.

13. The catadioptric imaging system of claim 12, wherein the catoptric region between the two facets is configured to reflect light from the world point within the field of view into neighboring edge regions of the two sensors.

14. The catadioptric imaging system of claim 13, wherein each facet of the plurality of facets has an effective viewpoint, and wherein each image of the viewpoints of the plurality of facets are imaged onto a separate sensors of the plurality of sensors.

15. The catadioptric imaging system of claim 14, wherein the lens has a multi-viewpoint topology corresponding the viewpoints of the plurality of facets.

16. The catadioptric imaging system of claim 13, wherein each facet of the plurality of facets has an effective viewpoint, and wherein the effective viewpoints of the plurality of facets coincide at a focal plane of the catoptric structure.

17. The catadioptric imaging system of claim 13, wherein each facet of the plurality of facets has an effective viewpoint, and wherein the effective viewpoints of the plurality of facets do not coincide at a focal plane of the catoptric structure.

18. The catadioptric imaging system of claim 13, The apparatus of claim 2, wherein:

the first field of view has a first azimuthal component and a first horizontal component;

the second field of view has a second azimuthal component that is substantially the same as the first azimuthal component; and

the second field of view has a second horizontal component that is smaller than the first horizontal component.

19. The catadioptric imaging system of claim 18, wherein the array of sensors comprises an array of rectangular sensors arranged in a radial array.

20. The catadioptric imaging system of claim 18, wherein a facet of the plurality of facets has a surface profile comprising a portion of a surface of revolution of a skewed or unskewed conic section from a first angle to a second angle.

21. The catadioptric imaging system of claim 20, wherein the angular distance between the first angle and the second angle determines the width of edge regions of the two sensors.

22. The catadioptric imaging system of claim 20, wherein the angular distance between the first angle and the second angle is

23. The catadioptric imaging system of claim 20, wherein the conic section is hyperbola.

24. The catadioptric imaging system of claim 13, wherein:

the first field of view as a first azimuthal component and a first horizontal component;

the second field of view has a second azimuthal component that is smaller than the first azimuthal component; and

the second field of view has a second horizontal component that is smaller than the first horizontal component.

25. The catadioptric imaging system of claim 24, wherein the facets of the plurality of facets are arranged on the surface of the catoptric structure in a plurality of azimuthal zones.

26. The catadioptric imaging system of claim 25, wherein the plurality of sensors is arrayed into a plurality of different resolution zones corresponding to the plurality of azimuthal zones.

27. A system comprising an image stitching module configured to:

receive a plurality of images from a corresponding plurality of image sensors arranged in an array, an image of the plurality of images having a central region comprising an image from a single facet of a catoptric structure and an edge region comprising an image from a catoptric region between two facets of the catoptric structure, wherein the catoptric region between the two facets is configured to reflect light from a world point within a first field of view of the catoptric structure onto two of the sensors of the plurality of sensors;

combine the plurality of images into a composite image using the edge regions from the plurality of images; and

provide the composite image to an image display module or and image recording module.

28. The system of claim 27, further configured to apply surface-based image transforms to the plurality of images to project the ages onto a rectilinear system.

29. The system of claim 27, wherein the step of combining the plurality of images into a composite image comprises applying a gradient descent algorithm based on a predetermined cost function.

30. The system of claim 29, wherein the cost function is configured to minimize visible transitions between images by spatially translating the images.

31. The system of claim 29, wherein the step of combining the plurality of images comprises calculating image derivatives between successive image frames within the edge regions.

32. The system of claim 29, wherein the step of combining the plurality of images comprises calculating image derivatives between successive image frames within the edge regions without calculating derivatives between successive image frames within the central regions.

33. The system of claim 29, wherein the step of combining the plurality of images comprises minimizing the cost function, C_d, is minimized with respect to two input images, I₁, I₂, in the form:

C_d(I;

I₁,I₂,w)=d(∇

Î

,∇

I₁,t₁∪

w,w)+d(∇

Î

,∇

I₂,t₂∪

w,U−

w), 

 

(11)

where w is a weighting value, t_i is the area of image, i, ω

is the area of the edge regions, Î

is an estimate of the composite image, and d is a distance function where

34. The system of claim 27, further comprising an image display module configured to receive the composite image and configured to display a reduced resolution portion of the image on a display device by correlating pixel values from predetermined subsets of the composite image and displaying the correlated pixel values on the display device.

35. The system of claim 27, further comprising an image display module configured to:

receive the composite image and to select a region of the composite image and display the region of the composite on the display device, and

to pan the displayed portion of the image by translating the selected region.

36. The system of claim 35, wherein the image display module is further configured to perform electronic frame stabilization by identifying the image of a reference world point as a reference point and translating the selected region to maintain the position of the image within the selected region with respect to the reference point.

37. The system of claim 27, further comprising an pattern recognition module configured to identify a silhouette or profile of a predetermined object within the composite image.

38. The system of claim 37, wherein the step of identifying the silhouette or profile comprises performing pixel-by-pixel frame subtraction or object edge extraction based on mean square error, peak signal-to-noise ratio, profile polar distribution, or polar compliance parameters.

39. The system of claim 37, further comprising an image compression module, configured to receive information regarding the identified silhouettes or profiles within the composite image from the pattern recognition module and configured to compress the composite image by compressing image regions within the identified silhouettes or profiles with a first compression ratio and compressing image regions outside the identified silhouettes or profiles with a second compression ratio.