Method and apparatus for a color scannerless range imaging system

• US 6,349,174 B1
• Filed: 05/17/2000
• Issued: 02/19/2002
• Est. Priority Date: 05/17/2000
• 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): PERKEY, WILLIAM B
• Application Number:
  US09/572,522
• Time in Patent Office: 643 Days
• Field of Search: 396/106, 396/89, 356/5.1, 356/5.11, 356/5.12, 356/5.13, 356/5.14, 356/5.15
• US Class Current: 396/106
• CPC Class Codes: G01S 17/36 with phase comparison between the received signal and the contemporaneously transmitted signal
• CPC Class Codes: G01S 17/89 for mapping or imaging
• CPC Class Codes: H04N 13/254 in combination with electromagnetic radiation sources for illuminating objects
• CPC Class Codes: H04N 5/2226 Determination of depth image, e.g. for foreground/background separation determining depth by image analysis in general G06T7/50; segmentation by image analysis in general G06T7/10

Abstract

A color scannerless range imaging system includes an illumination system for controllably illuminating a scene with modulated illumination and an image responsive element for capturing image light from the scene, including the modulated image light. The system establishes a primary optical path for directly image light toward the image responsive element. A beamsplitter located in the primary optical path separates the image light into two channels, a first channel including an infrared component and a second channel including a color texture component, whereby one of the channels traverses a secondary optical path distinct from the primary path. A modulating element is operative in the first channel to receive the infrared component and a modulating signal, and to generate a processed infrared component with phase data indicative of range information. An optical network is provided in the secondary optical path for recombining the secondary optical path into the primary optical path such that the processed infrared component and the color texture component are directly to the image responsive element.

Claims

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

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

(b) an image responsive element for capturing image light from the scene, including the modulated image light;

(c) one or more optical elements establishing a primary optical path for directing image light toward the image responsive element;

(d) a beamsplitter located in the primary optical path for separating the image light into two channels, a first channel including an infrared component and a second channel including a color texture component, at least one of said channels traversing a secondary optical path distinct form the primary path;

(e) a modulating element operative in the first channel to modulate the infrared component with a modulating signal, thereby generating a processed infrared component with phase data indicative of range information; and

(f) an optical network in the secondary optical path for recombining the secondary optical path into the primary optical path such that the processed infrared component and the color texture component are directed to the image responsive element.

2. The range imaging system as claimed in claim 1 further comprising means for alternately activating the channels to alternately provide the processed infrared component and the color texture component to the image responsive element.

3. The range imaging system as claimed in claim 2 wherein the color texture component is channeled through the secondary optical path and a shutter placed in the secondary path for controlling the passage of the color texture component.

4. The range imaging system as claimed in claim 1 wherein the modulating element is a micro-channel plate.

5. The range imaging system as claimed in claim 1 wherein the optical network comprises a mirror network for recombining the secondary optical path into the primary optical path such that the processed infrared component and the color texture component are directed to the image responsive element.

6. The range imaging system as claimed in claim 1 wherein the beamsplitter is a dichromatic beamsplitter.

7. The range imaging system as claimed in claim 2 wherein the means for alternately activating the channels is coupled to a shutter release in order to initiate an image capture of both color and range information with a single engagement of the shutter release.

8. The range imaging system as claimed in claim 1 wherein the elements (c) through (f) are included in an optical attachment that is mountable upon a conventional camera body.

9. The range imaging system as claimed in claim 1 wherein the infrared component includes a modulation component having the same modulating frequency as the modulating signal applied to the illumination system.

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

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

12. The range imaging system as claimed in claim 11 wherein each unique phase offset θ

is given by θ

_i=2π

i/3;

i=0,1,2.

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

14. The range imaging system as claimed in claim 1 wherein the image responsive element is a digital image sensor.

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

16. A color scannerless range imaging system for capturing both color and range information from a scene, said system comprising:

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

(b) an image responsive element for capturing image light from the scene, including the modulated image light;

(c) one or more optical elements establishing a primary optical path for directing image light toward the image responsive element;

(d) means located in the primary optical path for separating the image light an infrared component and a color texture component, wherein the color texture component traverses a secondary optical path distinct from the primary optical path;

(e) a modulating element operative to modulate the infrared component with a modulating signal, thereby generating a processed infrared component with phase data indicative of range information;

(f) one or more optical control elements placed in the secondary path of the color texture component for controlling the passage of the color texture component and its recombination with the primary optical path; and

(g) means for alternately activating the modulating element and the one or more optical control elements to alternately provide the processed infrared component and the color texture component to the image responsive element.

17. The range imaging system as claimed in claim 16 wherein the one or more optical control elements includes a shutter placed in the secondary path for controlling the passage of the color texture component.

18. The range imaging system as claimed in claim 16 wherein the one or more optical control elements include a mirror network for recombining the secondary optical path into the primary optical path such that the processed infrared component and the color texture component are directed to the image responsive element.

19. The range imaging system as claimed in claim 16 wherein the modulating element is a micro-channel plate.

20. The range imaging system as claimed in claim 16 wherein the means located in the primary optical path for separating the image light comprises a dichromatic beamsplitter.

21. The range imaging system as claimed in claim 16 wherein the means for alternately activating the modulating element and the one or more optical control elements is coupled to a shutter release in order to initiate an image capture of both color and range information with a single engagement of the shutter release.

22. The range imaging system as claimed in claim 16 wherein the elements (c) through (f) are included in an optical attachment that is mountable to a conventional camera body.

23. The range imaging system as claimed in claim 16 wherein the infrared component includes a modulation component having the same modulating frequency as the modulating signal applied to the illumination system.

24. A method for capturing both color and range information from a scene on an image responsive element, said system comprising the steps of:

(a) controllably illuminating the scene with modulated illumination, whereby some of the modulated illumination is reflected from objects in the scene;

(b) capturing image light from the scene, including the modulated image light;

(c) establishing a primary optical path for directing image light toward the image responsive element;

(d) separating the image light into two channels, a first channel including an infrared component and a second channel including a color texture component, at least one of said channels traversing a secondary optical path distinct from the primary path;

(e) applying a modulating signal to the infrared component in the first channel and generating a processed infrared component with phase data indicative of range information; and

(f) recombining the secondary optical path into the primary optical path such that the processed infrared component and the color texture component are directed through the primary optical path to the image responsive element.

25. The method as claimed in claim 24 further comprising the step of alternately activating the channels to alternately provide the processed infrared component and the color texture component to the image responsive element.

26. The method as claimed in claim 25 wherein the color texture component is channeled through the secondary optical path and the method further includes the step of shuttering the secondary path in order to control the passage of the color texture component.

27. The method as claimed in claim 24 further comprising the step of storing the color and range information as a bundle of associated images.

28. The method as claimed in claim 27 further including the step of capturing a plurality of images of the reflected modulated illumination, wherein each image incorporates the effect of a predetermined modulation frequency together with a phase offset unique for each image.

29. The method as claimed in claim 28 wherein each unique phase offset θ

is given by θ

_i=2π

i/3;

i=0,1,2.