Method and apparatus for omnidirectional imaging

• US 6,304,285 B1
• Filed: 06/16/1998
• Issued: 10/16/2001
• Est. Priority Date: 06/16/1998
• Status: Expired due to Fees

• Current Assignee: Technest Holdings, Inc. (AccelPath, Inc.)
• Original Assignee: Genex Technologies Incorporated (AccelPath, Inc.)
• Inventors: Geng, Zheng Jason
• Primary Examiner(s): Kelley, Chris
• Assistant Examiner(s): VO, TUNG T
• Application Number:
  US09/098,322
• Time in Patent Office: 1,218 Days
• Field of Search: 348/36, 348/38, 348/39, 348/42, 250/208.1, 250/208.6, 356/28, 356/325, 356/318, 359/725, 359/726, 359/727, 359/728, 359/729
• US Class Current: 348/36
• CPC Class Codes: G06T 7/521 from laser ranging, e.g. using interferometry; from the projection of structured light
• CPC Class Codes: G06T 7/593 from stereo images
• CPC Class Codes: G06T 7/97 Determining parameters from multiple pictures depth or shape recovery from multiple images G06T7/55; stereo camera calibration G06T7/85
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 2013/0088 Synthesising a monoscopic image signal from stereoscopic images, e.g. synthesising a panoramic or high resolution monoscopic image
• 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 23/698 for achieving an enlarged field of view, e.g. panoramic image capture
• CPC Class Codes: H04N 5/2628 Alteration of picture size, shape, position or orientation, e.g. zooming, rotation, rolling, perspective, translation

Abstract

An omnidirectional imaging system comprising a reflective mirror for viewing object within a hemispherical field of view form a single virtual view point at the local center of said reflective mirror, a projector for projecting a light beam toward said reflective mirror, and a variable wavelength filter optically positioned between said projector and said reflective mirror for generating a pattern having a spatially distributed wavelength spectrum of said reflective mirror, where a generator responsive to the hemispherical image data for generating three-dimensional image.

Claims

1. An omnidirectional imaging system comprising:

a reflective mirror for viewing objects within a hemispherical field of view from a single virtual viewpoint at the focal center of said reflective mirror;

an image sensor that generates hemispherical image data signals in response to light rays reflected from said reflective mirror;

a projector for projecting a light beam toward said reflective mirror;

a variable wavelength filter optically positioned between said projector and said reflective mirror for generating a pattern having a spatially distributed wavelength spectrum on said reflective mirror; and

a data generator responsive to said hemispherical image data signals for generating three-dimensional data for objects within said hemispherical field of view.

2. The omnidirectional camera system of claim 1, wherein said reflective mirror is aligned with the optical axis of said image sensor.

3. The apparatus of claim 1, wherein the reflective mirror is a substantially hyperbolic mirror.

4. The apparatus of claim 1, wherein the spatially distributed wavelength spectrum generated by the variable wavelength filter comprises a rainbow-like pattern.

5. The apparatus of claim 4, wherein the rainbow-like pattern is a plurality of light rings, and wherein the wavelength of the rainbow-like light rings are proportional to respective positions of said rings measured in radians from the center of said variable wavelength filter.

6. The apparatus of claim 1, further comprising a position calculator responsive to predetermined geometric parameters of said reflective mirror, of said projector and of said video sensor, wherein said position calculator determines unique distance measurements for objects in said field of view of said video sensor.

7. An improved method for generating two dimensional video images of a scene, comprising the steps of:

positioning a reflective mirror structured to satisfy an optical single viewpoint constraint for viewing objects within said scene of a hemispherical field of view;

projecting a light beam toward said reflective mirror;

generating a pattern having a spatially distributed wavelength spectrum on said reflective mirror using a variable wavelength filter;

actuating a video sensor optically aligned with said reflective mirror for generating hemispherical video image data signals in response to light rays reflected from said reflective mirror, wherein said video sensor views objects within a hemispherical field of view from a single virtual viewpoint at the focal center of said reflective mirror; and

storing said hemispherical image data signals.

8. The method of claim 7, wherein the reflective mirror used in the positioning step is substantially hyperbolic.

9. The method of claim 7, wherein the pattern formed in the generating step is a rainbow-like pattern.

10. The method of claim 9, wherein the rainbow-like pattern formed in the generating step is a plurality of light rings, and wherein the wavelength of the rainbow-like light rings are proportional to respective positions of said rings measured in radians from the center of the variable wavelength filter.

11. The method of claim 7, further comprising the step of determining unique distance measurements for objects in the field of view of said video sensor using a position calculator responsive to predetermined geometric parameters of the reflective mirror, of the projector and of the video sensor.

12. An omnidirectional imaging apparatus, comprising:

a first reflective mirror configured to satisfy an optical single viewpoint constraint;

an image sensor optically aligned with said first reflective mirror for generating two dimensional image data signals;

a second reflective mirror disposed in a spaced relationship with respect to said first reflective mirror such that a reflective surface on said first reflective mirror faces a reflective surface on said second reflective mirror;

a projector for projecting a light beam toward said second reflective mirror; and

a variable wavelength filter optically positioned between said projector and said second reflective mirror for generating a pattern having a spatially distributed wavelength spectrum on said second reflective mirror.

13. The apparatus of claim 12, wherein the first and second reflective mirrors are substantially hyperbolic mirrors.

14. The apparatus of claim 12, wherein the spatially distributed wavelength spectrum generated by the variable wavelength filter comprises a rainbow-like pattern.

15. The apparatus of claim 14, wherein the rainbow-like pattern is a plurality of light rings, and wherein the wavelength of the rainbow-like light rings are proportional to respective positions of said rings measured in radians from the center of said variable wavelength filter.

16. The apparatus of claim 12, further comprising a position calculator responsive to predetermined geometric parameters of said first and second reflective mirrors, of said projector and of said video sensor, wherein said position calculator determines unique distance measurements for objects in said field of view of said video sensor.