Method and apparatus for a color scannerless range imaging system

• US 6,456,793 B1
• Filed: 08/03/2000
• Issued: 09/24/2002
• Est. Priority Date: 08/03/2000
• Status: Expired due to Term

• Current Assignee: Monument Peak Ventures, LLC (Dominion Harbor Enterprises, LLC)
• Original Assignee: Eastman Kodak Company
• Inventors: Ray, Lawrence A., Gabello, Louis R.
• Primary Examiner(s): Adams, Russell
• Assistant Examiner(s): Smith, Arthur A
• Application Number:
  US09/631,601
• Time in Patent Office: 782 Days
• Field of Search: 396/89, 396/155, 396/222, 396/311, 396/429, 356/2, 356/3, 356/5.1, 250/214.VT
• US Class Current: 396/89
• CPC Class Codes: G01S 17/89 for mapping or imaging

Abstract

A color scannerless range imaging system includes an illumination system for illuminating the scene with modulated illumination of a predetermined modulation frequency and an image capture section positioned in an optical path of the reflected illumination from the scene for capturing a plurality of images including (a) at least one range image corresponding to the reflected modulated illumination and including a phase delay corresponding to the distance of objects in the scene from the range imaging system, and (b) at least one other image of reflected unmodulated illumination corresponding to color in the scene. The image capture section includes a color filter array arranged with a first type of color filter that preferentially transmits the reflected modulated illumination and one or more other color filters that preferentially transmit the reflected unmodulated illumination, an image intensifier receiving the reflected illumination and including a modulating stage for modulating the reflected modulated illumination from the scene, thereby generating the range information, and an image responsive element for capturing an output of the image intensifier, including the range image and the other image of reflected unmodulated image light corresponding to color in the scene. The image intensifier is structured with channels that generally correspond to the color filter array such that the intensifier provides the range image from channels corresponding to the first color filter and the other image corresponding to color in the scene from channels corresponding to the other color filters.

Claims

1. A color scannerless range imaging system for capturing both color and range information of a scene, said system comprising;

an illumination system for controllably illuminating the scene with modulated illumination of a predetermined modulation frequency, whereby some of the modulated illumination is reflected from objects in the scene;

an image capture section positioned in an optical path of the reflected illumination from the scene for capturing a plurality of images thereof, including (a) at least one range image corresponding to the reflected modulated illumination, whereby the modulation of the reflected modulated illumination incorporates a phase delay corresponding to the distance of objects in the scene from the range imaging system, and (b) at least one other image of reflected unmodulated illumination corresponding to color in the scene, said image capture section comprising;

a color filter array positioned in the optical path of the reflected illumination and comprised of a predetermined filter pattern including a first color filter that preferentially transmits the reflected modulated illumination and one or more other color filters that preferentially transmit the reflected unmodulated illumination;

an image intensifier receiving the reflected illumination and including a modulating stage for modulating the reflected modulated illumination from the scene with the predetermined modulation frequency, thereby generating the range information, wherein the image intensifier has a channel structure that generally corresponds to the predetermined pattern of the color filter array such that the intensifier provides the range image from channels corresponding to said first color filter and the other image corresponding to color in the scene from channels corresponding to said one or more other color filters; and

an image responsive element for capturing an output of the image intensifier, including the range image corresponding to the reflected modulated image light and the other image of reflected unmodulated image light corresponding to color in the scene.

2. The range imaging system as claimed in claim 1 wherein the intensifier is a micro-channel plate.

3. The range imaging system as claimed in claim 1 wherein the image intensifier is interposed in the optical path between the image responsive element and the color filter array.

4. The range imaging system as claimed in claim 1 wherein the image responsive element is a photosensitive film.

5. The range imaging system as claimed in claim 1 wherein the image responsive element is an electronic image sensor.

6. The range imaging system as claimed in claim 1 farther comprising means for storing the color and range images as a bundle of associated images.

7. The range imaging system as claimed in claim 1 wherein the image responsive element captures a plurality of range images corresponding to the reflected modulated illumination, wherein each range image incorporates the effect of the predetermined modulation frequency together with a phase offset unique for each image.

8. The range imaging system as claimed in claim 7 wherein each unique phase offset θ

is given by θ

_i=2π

i/3;

i=0,1,2.

9. The range imaging system as claimed in claim 1 wherein the illumination system includes a laser illuminator for producing the modulated illumination.

10. The range imaging system as claimed in claim 1 wherein the predetermined modulating frequency is an infra-red frequency and said first color filter is an infra-red color filter.

11. The range imaging system as claimed in claim 1 wherein said one or more other color filters comprise a set of color filters including at least any two filters selected from the group of red, green and blue filters.

12. The range imaging system as claimed in claim 1 wherein the illumination system also emits unmodulated illumination and the reflected unmodulated illumination includes at least some of the emitted unmodulated illumination.

13. The range imaging system as claimed in claim 1 wherein the reflected unmodulated illumination includes ambient illumination reflected from objects in the scene.

14. The range imaging system as claimed in claim 2 wherein the microchannel plate includes channels forming a hexagonal lattice structure and the color filter array has a hexagonal pattern that substantially matches the lattice structure of the microchannel plate.

15. A color scannerless range imaging system for capturing both color and range information of a scene, said system comprising;

an illumination system for controllably illuminating the scene with modulated illumination of a predetermined modulation frequency, whereby some of the modulated illumination is reflected from objects in the scene;

an image capture section positioned in an optical path of the reflected illumination from the scene for capturing a plurality of images thereof, including (a) at least one range image corresponding to the reflected modulated illumination, whereby the modulation of the reflected modulated illumination incorporates a phase delay corresponding to the distance of objects in the scene from the range imaging system, and (b) at least one other image of reflected unmodulated illumination corresponding to color in the scene, said image capture section comprising;

a color filter array positioned in the optical path of the reflected illumination and comprised of a predetermined filter pattern including a first color filter that preferentially transmits the reflected modulated illumination and one or more other color filters that preferentially transmit the reflected unmodulated illumination;

an image intensifier receiving the reflected illumination and including a modulating stage for modulating the reflected modulated illumination from the scene with the predetermined modulation frequency, thereby generating the range information, wherein the image intensifier has a channel structure that generally corresponds to the predetermined pattern of the color filter array such that the intensifier provides the range image from channels corresponding to said first color filter and the other image corresponding to color in the scene from channels corresponding to said one or more other color filters;

an image responsive element for capturing an output representing the output image plane of the image intensifier, including the range image corresponding to the reflected modulated image light and the other image of reflected unmodulated image light corresponding to color in the scene; and

a range processor for processing the captured output image to infer color information from the spatial coordinates of the individual points on the output image plane.

16. The range imaging system as claimed in claim 15 wherein the intensifier is a micro-channel plate.

17. The range imaging system as claimed in claim 15 wherein the image intensifier is interposed in the optical path between the image responsive element and the color filter array.

18. The range imaging system as claimed in claim 15 wherein the image responsive element is a photosensitive film.

19. The range imaging system as claimed in claim 15 wherein the image responsive element is an electronic image sensor.

20. The range imaging system as claimed in claim 15 further comprising means for storing the color and range images as a bundle of associated images.

21. The range imaging system as claimed in claim 15 wherein the image responsive element captures a plurality of range images corresponding to the reflected modulated illumination, wherein each range image incorporates the effect of the predetermined modulation frequency together with a phase offset unique for each image.

22. The range imaging system as claimed in claim 21 wherein each unique phase offset θ

is given by θ

_i=2π

i/3;

i=0,1,2.

23. The range imaging system as claimed in claim 15 wherein the illumination system includes a laser illuminator for producing the modulated illumination.

24. The range imaging system as claimed in claim 15 wherein the predetermined modulating frequency is an infra-red frequency and said first color filter is an infra-red color filter.

25. The range imaging system as claimed in claim 15 wherein said one or more other color filters comprise a set of color filters including at least any two filters selected from the group of red, green and blue filters.

26. The range imaging system as claimed in claim 15 wherein the illumination system also emits unmodulated illumination and the reflected unmodulated illumination includes at least some of the emitted unmodulated illumination.

27. The range imaging system as claimed in claim 15 wherein the reflected unmodulated illumination includes ambient illumination reflected from objects in the scene.

28. The range imaging system as claimed in claim 16 wherein the microchannel plate includes channels forming a hexagonal lattice structure and the color filter array has a hexagonal pattern that substantially matches the lattice structure of the microchannel plate.

29. The range imaging system as claimed in claim 28 wherein the range processor operates on the hexagonal pattern to interpolate color from the output of the image intensifier.