Information processing apparatus, information processing method, and storage medium

Patent metadata

Field	Value
Publication number	US-10032279-B2
Application number	US-201615048601-A
Country	US
Kind code	B2
Filing date	Feb 19, 2016
Priority date	Feb 23, 2015
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

An information processing apparatus includes an image acquisition unit configured to acquire an image obtained by imaging a target object onto which a pattern having a bright portion and a dark portion is projected by a projection unit, an allocation unit configured to allocate, to a pixel in the image, a label corresponding to luminance of the pixel by referring to a characteristic of the pattern, and a correspondence relationship derivation unit configured to derive a correspondence relationship between a position of the pattern in a projection plane of the projection unit and a position of the pattern in the acquired image and a three-dimensional coordinate derivation unit configured to derive three-dimensional coordinates of a surface of the target object based on the derived correspondence relationship.

First claim

What is claimed is:

1. An information processing apparatus comprising:
one or more memories storing instructions; and
one or more processors that, when executing the instructions, causes the information processing apparatus to:
acquire a plurality of images obtained by imaging a target object onto which a plurality of patterns having a bright portion and a dark portion are projected in a time series by a projector;
allocate, to each pixel in the plurality of images, a label corresponding to luminance of the pixel by referring to a characteristic of the plurality of patterns;
change the allocated label based on a time-series change of luminance of the projected plurality of patterns;
derive correspondence relationships between positions of the plurality of patterns in a projection plane of the projector and positions of the plurality of patterns in the acquired image based on the changed label; and
derive three-dimensional coordinates of a surface of the target object based on the derived correspondence relationships.

2. The information processing apparatus according to claim 1 , wherein the instructions further cause the information processing apparatus to change the allocated label based on whether a change of labels of adjacent pixels in each image exists in a change of luminance of the projected plurality of patterns.

3. The information processing apparatus according to claim 1 , wherein the instructions further cause the information processing apparatus to allocate respective different labels according to whether the luminance of each pixel in the image is greater than a threshold value or is less than the threshold value.

4. The information processing apparatus according to claim 1 , wherein the plurality of patterns are Gray code patterns.

5. The information processing apparatus according to claim 1 , wherein the instructions further cause the information processing apparatus to derive three-dimensional coordinates of a surface of the target object with a boundary position between the bright portion and the dark portion of the plurality of patterns included in the plurality of images set as a measurement point.

6. An information processing apparatus comprising:
one or more memories storing instructions; and
one or more processors that, when executing the instructions, causes the information processing apparatus to:
acquire an image obtained by imaging a target object onto which a pattern having a bright portion and a dark portion is projected by a projector;
detect a boundary position between the bright portion and the dark portion of the pattern in the image;
allocate, to a pixel in the image, a label corresponding to luminance of the pixel by referring to a characteristic of the pattern;
change the allocated label based on a time-series change of luminance of a projected plurality of patterns
derive a correspondence relationship between a position of the pattern in a projection plane of the projector and a position of the pattern in the acquired image based on the changed label; and
derive three-dimensional coordinates of a surface of the target object based on the derived correspondence relationship.

7. The information processing apparatus according to claim 6 , wherein the instructions further cause the information processing apparatus to detect the boundary position based on the allocated label.

8. The information processing apparatus according to claim 6 , wherein the instructions further cause the information processing apparatus to:
allocate a first label to a pixel having a luminance value larger than a first threshold value, allocate a second label to a pixel having a luminance value smaller than the first threshold value and larger than a second threshold value, and allocate a third label to a pixel having a luminance value smaller than the second threshold value; and
change the label of a pixel having the second label to the first label or the third label in view of the boundary position.

9. The information processing apparatus according to claim 8 , wherein the first threshold value and the second threshold value are determined based on a degree of reliability of the labels.

10. The information processing apparatus according to claim 8 , wherein the instructions further cause the information processing apparatus to:
detect the boundary position based on a pixel having the second label and adjacent pixels having respective different labels; and
change the label of a pixel having the second label to the first label or the third label based on a distribution of the labels of pixels neighboring the boundary position.

11. The information processing apparatus according to claim 8 , wherein the instructions further cause the information processing apparatus to change the label of a pixel having the second label to the first label or the third label based on a characteristic of the pattern.

12. The information processing apparatus according to claim 8 , wherein the instructions further cause the information processing apparatus to change the label allocated to the associated pixel based on luminance values or labels of a plurality of pixels neighboring the associated pixel.

13. The information processing apparatus according to claim 6 , wherein the pattern includes a plurality of patterns that is projected in time series, and
wherein the instructions further cause the information processing apparatus to allocate the label further in view of a time-series change of luminance of the projected plurality of patterns.

14. The information processing apparatus according to claim 6 , wherein the pattern is a Gray code pattern.

15. An information processing method comprising:
acquiring a plurality of images obtained by imaging a target object onto which a plurality of patterns having a bright portion and a dark portion are projected by a projector;
allocating, to each pixel in the plurality of images, a label corresponding to luminance of the pixel by referring to a characteristic of the plurality of patterns;
changing the allocated label based on a time-series change of luminance of the projected plurality of patterns;
deriving a correspondence relationship between positions of the plurality of patterns in a projection plane of the projector and positions of the plurality of patterns in the acquired image based on the changed label; and
deriving three-dimensional coordinates of a surface of the target object based on the derived correspondence relationships.

16. An information processing method comprising:
acquiring an image obtained by imaging a target object onto which a pattern having a bright portion and a dark portion is projected by a projector;
detecting a boundary positioning between the bright portion and the dark portion of the pattern in the image;
allocating, to a pixel in the image, a label corresponding to luminance of the pixel by referring to a characteristic of the pattern;
changing the allocated label based on a time-series change of luminance of a projected plurality of patterns
deriving a correspondence relationship between a position of the pattern in a projection plane of the projector and a position of the pattern in the acquired image based on the changed label; and
deriving three-dimensional coordinates of a surface of the target object based on the derived correspondence relationship.

17. A non-transitory computer-readable storage medium storing a program that, when executed by a computer, causes the computer to:
acquire a plurality of images obtained by imaging a target object onto which a plurality of patterns

Assignees

• Canon Kk

Inventors

• Inaba Masaki
• Higo Tomoaki

Classifications

• G06T7/13

  Edge detection · CPC title

• G06T7/521 Primary

  from laser ranging, e.g. using interferometry; from the projection of structured light · CPC title

• G06T7/0057 Primary

  Physics · mapped topic