Method and device for detecting three-dimensional information

• US 20060120595A1
• Filed: 01/05/2006
• Published: 06/08/2006
• Est. Priority Date: 10/15/1998
• Status: Active Grant

• Current Assignee: Nippon Hoso Kyokai
• Original Assignee: Nippon Hoso Kyokai
• Inventors: Iizuka, Keigo, Nakamura, Haruhito, Aida, Tahito, Kawakita, Masahiro
• Granted Patent: US 7,486,804 B2
• Time in Patent Office: Days
• US Class Current: 382/154
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures
• CPC Class Codes: G01S 17/89 for mapping or imaging

Abstract

An image of an object illuminated by illumination light having given intensity is formed as an optical image. The distance between respective points of the object is determined on the basis of a video which is obtained by acquiring the optical image with a given image pick-up gain. Here, either the intensity of the illumination light or the image pick-up gain is changed with time. The distribution of intensity of the image acquired by utilization of such intensity or image pick-up gain reflects a time lag between the time at which the illumination light is emitted from a light source and the time at which the light reflected from individual points of the object reaches an image pick-up device. The distribution of intensity includes information pertaining to the distance between the light source and the respective points of the object.

Claims

1. A method of detecting three-dimensional information, comprising:

illuminating an object with an illumination light;

acquiring an image of the object illuminated by the illumination light by acquisition of at least two image pick-up gain, at least one of said image pick-up gain changing with time, and the image pick-up gain having slower changing rate than a changing rate of the illumination light, wherein the image is acquired a plurality of times by an image pick-up element having storage effect; and

detecting a distance between individual points of the object on the basis of the image obtained;

wherein

the distance between respective points of the object is detected at a speed at which three-dimensional information is followed real time within a period of time corresponding to a frame of a video signal.

3. The method of detecting three-dimensional information as defined in claim 1, wherein

first and second optical images of the object illuminated by first and second illumination light which illuminate with single intensity over a predetermined period of time, are formed;

first and second images are obtained alternately by acquiring the first and second optical images with first and second image pick-up gains, the first and second images obtained are stored; and

the distance between respective points of the object is detected from the first and second images which are detected sequentially for each frame of the video signal.

5. The method of detecting three-dimensional information as defined in claim 1, wherein the first image pick-up gain changes with time, and the second image pick-up gain is uniform.

6. The method of detecting three-dimensional information as defined in claim 1, wherein the first image pick-up gain is increased with time, and the second image pick-up gain is decreased with time.

2. A method of detecting three-dimensional information, comprising:

illuminating an object with an illumination light;

acquiring an image of the object illuminated by the illumination light by acquisition of at least two image pick-up gain, at least one of said image pick-up gain changing with time, and the image pick-up gain having slower changing cycle than a illuminating time of the illumination light with given level of intensity, wherein the image of the object is acquired a plurality of times by an image pick-up element having storage effect; and

detecting a distance between individual points of the object on the basis of the image obtained;

wherein

the distance between respective points of the object is detected at a speed at which three-dimensional information is followed real time within a period of time corresponding to a frame of a video signal.

4. The method of detecting three-dimensional information as defined in claim 2, wherein

first and second optical images of the object illuminated by first and second illumination light which illuminate with single intensity over a predetermined period of time, are formed;

first and second images are obtained alternately by acquiring the first and second optical images with first and second image pick-up gains, the first and second images obtained are stored; and

the distance between respective points of the object is detected from the first and second images which are detected sequentially for each frame of the video signal.

7. The method of detecting three-dimensional information as defined in claim 2, wherein the first image pick-up gain changes with time, and the second image pick-up gain is uniform.

8. The method of detecting three-dimensional information as defined in claim 2, wherein the first image pick-up gain is increased with time, and the second image pick-up gain is decreased with time.