Systems And Methods For Panoramic Imaging

• US 20110211039A1
• Filed: 04/22/2011
• Published: 09/01/2011
• Est. Priority Date: 09/21/2007
• Status: Active Grant

• Current Assignee: Gurunandan Krishnan, Shree K. Nayar
• Original Assignee: Gurunandan Krishnan, Shree K. Nayar
• Inventors: Nayar, Shree K., Krishnan, Gurunandan
• Granted Patent: US 8,817,066 B2
• Time in Patent Office: Days
• US Class Current: 348/36
• CPC Class Codes: G02B 13/06 Panoramic objectives; So-called "sky lenses" including panoramic objectives having reflecting surfaces
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 7/182 for mirrors
• CPC Class Codes: G06T 3/4038 Image mosaicing, e.g. composing plane images from plane sub-images
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: H04N 23/51 Housings
• CPC Class Codes: H04N 23/55 Optical parts specially adapted for electronic image sensors; Mounting thereof
• CPC Class Codes: H04N 23/58 Means for changing the camera field of view without moving the camera body, e.g. nutating or panning of optics or image sensors
• CPC Class Codes: H04N 23/60 Control of cameras or camera modules
• CPC Class Codes: H04N 23/698 for achieving an enlarged field of view, e.g. panoramic image capture

Abstract

Systems and methods for panoramic imaging are disclosed herein. An exemplary system of the disclosed subject matter for panoramic imaging includes a fisheye lens, a mirror optically coupled to the fisheye lens, and a detector for capturing light incident on the fisheye lens and reflected from the mirror. In some embodiments, the mirror is a spherical mirror. In some embodiments, the mirror is positioned coaxially with regard to the fisheye lens. In some embodiments, the system is further configured to satisfy the following conditions that the upper angle of a desired field of view is equal to the upper angle of a field of view of the fisheye lens, the lower angle of the desired field of view is less than or equal to the lower angle of a field of view of the mirror, and the angle of overlap between the field of view of the mirror and the field of view of the fisheye lens is equal to the difference between the lower angle of the field of view of the fisheye lens and the upper angle of the field of view of the mirror.

Claims

1. A mirror assembly adapted for use in a panoramic imaging system, comprising:

a mirror for optically coupling to a fisheye lens for reflecting an image of the field of view through the fisheye lens; and

a housing having a first end and a second end, the mirror being secured proximate to the first end, and the second end having an engagement portion for securing the mirror assembly to the panoramic imaging system,

wherein, when the mirror assembly is secured to the panoramic imaging system, the mirror is optically coupled to the fisheye lens and a detector for capturing a panoramic image.

2. The mirror assembly of claim 1, wherein the mirror is a spherical mirror.

3. The mirror assembly of claim 1, wherein a radius of curvature of the mirror and a width of the mirror are predetermined as a function of a position of the mirror with respect to the fisheye lens.

4. The mirror assembly of claim 1, wherein the housing further comprises a cylindrical transparent wall disposed between the first end and the second end.

5. The mirror assembly of claim 1, wherein the engagement portion comprises a screw thread.

6. The mirror assembly of claim 1, wherein, when the mirror assembly is secured to the panoramic imaging system, the mirror is positioned coaxially with regard to the fisheye lens.

7. The mirror assembly of claim 1, wherein, when the mirror assembly is secured to the panoramic imaging system, a lower angle of a field of view of the panoramic imaging system is less than or equal to a lower angle of a field of view of the mirror.

8. The mirror assembly of claim 1, wherein, when the mirror assembly is secured to the panoramic imaging system, an angle of overlap between a field of view of the mirror and a field of view of the fisheye lens is equal to the difference between a lower angle of the field of view of the fisheye lens and an upper angle of the field of view of the mirror.

9. The mirror assembly of claim 1, wherein a processor is operatively coupled to the detector, and a memory is operatively coupled to the processor, the memory storing program instructions, and wherein, when the mirror assembly is secured to the panoramic imaging system, the program instructions being executed by the processor cause the processor to utilize the detector to:

capture a first portion of an image of a field of view transmitted directly through the fisheye lens, and

capture a second portion of the image of the field of view reflected from the mirror through the fisheye lens.

10. The mirror assembly of claim 8, wherein the memory stores program instructions that when executed by the processor, further cause the processor to stitch together the first portion of the captured image and the second portion of the captured image to form one or more panoramic images.

11. The mirror assembly of claim 9, wherein the stitching together of the first portion of the captured image and the second portion of the captured image is performed utilizing a scale-invariant feature transform algorithm.

12. The mirror assembly of claim 9, wherein the memory stores program instructions that when executed by the processor, further cause the processor to calibrate the system.

13. The mirror assembly of claim 11, wherein calibrating the system comprises calibrating the mirror by determining the center of curvature and orientation of the mirror.

14. The mirror assembly of claim 9, wherein the memory stores program instructions that, when executed by the processor, further cause the processor generate a table of correspondence between captured image pixel locations and panorama pixel locations.

15. The mirror assembly of claim 8, wherein the memory stores program instructions that when executed by the processor, further cause the processor generate a table of correspondence between captured image pixel locations and panorama pixel locations.