Information processing apparatus, method, and storage medium

Patent metadata

Field	Value
Publication number	US-10979694-B2
Application number	US-201816050979-A
Country	US
Kind code	B2
Filing date	Jul 31, 2018
Priority date	Nov 5, 2013
Publication date	Apr 13, 2021
Grant date	Apr 13, 2021

Abstract

To perform a high-accuracy three-dimensional measurement by performing an appropriate calibration in accordance with various temperature changes, an information processing apparatus that decides a temperature-dependent parameter of a projection apparatus configured to project a pattern onto a measurement target object to perform a three-dimensional measurement includes a holding unit configured to hold a relationship in which the temperature-dependent parameter of the projection apparatus is set as a temperature function, a temperature input unit configured to input a temperature of the projection apparatus, and a temperature-dependent parameter decision unit configured to decide the temperature-dependent parameter of the projection apparatus based on the temperature of the projection apparatus which is input by the temperature input unit and the relationship.

First claim

What is claimed is:

1. An information processing apparatus that corrects image coordinates of a projection apparatus configured to project a pattern onto a measurement target object to perform a three-dimensional measurement, the information processing apparatus comprising:
one or more processors, and the one or more processors function as following units:
a decomposition unit configured to decompose respective variations of image coordinates in a plurality of images captured at different temperatures into parameters representing magnitudes of a plurality of predetermined movement components;
a calculation unit configured to calculate respective correction parameters for the decomposed parameters expressed in the plurality of predetermined movement components;
a derivation unit configured to derive, for each of the decomposed parameters expressed in the plurality of predetermined movement components, a relationship in which the correction parameter is set as a temperature function based on combinations of correction parameters and temperatures in capturing the plurality of images;
a temperature input unit configured to input a temperature of the projection apparatus;
a determination unit configured to determine respective correction parameters expressed in the plurality of predetermined movement components based on the input temperature of the projection apparatus and the derived relationship; and
a correction unit configured to correct the image coordinates of the projection apparatus based on the determined respective correction parameters expressed in the plurality of predetermined movement components.

2. The information processing apparatus according to claim 1 , wherein the predetermined movement components include a translation component.

3. The information processing apparatus according to claim 1 , wherein the predetermined movement components include a scaling component.

4. The information processing apparatus according to claim 1 , wherein the predetermined movement components include a rotation component.

5. The information processing apparatus according to claim 1 , wherein the one or more processors further function as:
an image input unit configured to input an image obtained by capturing the measurement target object onto which the pattern is projected by the projection apparatus;
a detection unit configured to detect a pattern from the input image; and
a coordinate calculation unit configured to calculate a three dimensional coordinate on a surface of the measurement target object based on an association between the detected pattern and the projected pattern and the corrected image coordinates.

6. An information processing apparatus that corrects image coordinates of an imaging apparatus configured to capture an image of a measurement target object to perform a three-dimensional measurement, the information processing apparatus comprising:
one or more processors, and the one or more processors function as following units:
a decomposition unit configured to decompose respective variations of image coordinates in a plurality of images captured at different temperatures into parameters representing magnitudes of a plurality of predetermined movement components;
a calculation unit configured to calculate respective correction parameters for the decomposed parameters expressed in the plurality of predetermined movement components;
a derivation unit configured to derive, for each of the decomposed parameters expressed in the plurality of predetermined movement components, a relationship in which the correction parameter is set as a temperature function based on combinations of correction parameters and temperatures in capturing the plurality of images;
a temperature input unit configured to input a temperature of the imaging apparatus;
a determination unit configured to determine respective correction parameters expressed in the plurality of predetermined movement components based on the input temperature of the imaging apparatus and the derived relationship; and
a correction unit configured to correct the image coordinates of the imaging apparatus based on the determined respective correction parameters expressed in the plurality of predetermined movement components.

7. The information processing apparatus according to claim 6 , wherein the predetermined movement components include a translation component.

8. The information processing apparatus according to claim 6 , wherein the predetermined movement components include a scaling component.

9. The information processing apparatus according to claim 6 , wherein the predetermined movement components include a rotation component.

10. The information processing apparatus according to claim 6 , further comprising:
a projection apparatus configured to project a pattern onto the measurement target object,
wherein the one or more processors further function as:
an image input unit configured to input an image obtained by capturing the measurement target object, onto which the pattern is projected by the projection apparatus, captured by the imaging apparatus;
a detection unit configured to detect a pattern from the input image; and
a coordinate calculation unit configured to calculate a three dimensional coordinate on a surface of the measurement target object based on an association between the detected pattern and the projected pattern and the corrected image coordinates.

11. A method of correcting image coordinates of a projection apparatus configured to project a pattern onto a measurement target object to perform a three-dimensional measurement, the method comprising:
decomposing respective variations of image coordinates in a plurality of images captured at different temperatures into parameters representing magnitudes of a plurality of predetermined movement components;
calculating respective correction parameters for the decomposed parameters expressed in the plurality of predetermined movement components;
deriving, for each of the decomposed parameters expressed in the plurality of predetermined movement components, a relationship in which the correction parameter is set as a temperature function based on combinations of correction parameters and temperatures in capturing the plurality of images;
inputting a temperature of the projection apparatus;
determining respective correction parameters expressed in the plurality of predetermined movement components based on the input temperature of the projection apparatus and the derived relationship; and
correcting the image coordinates of the projection apparatus based on the determined respective correction parameters expressed in the plurality of predetermined movement components.

12. A non-transitory computer readable storage medium storing a computer program for causing a computer to function as respective units of an information processing apparatus that corrects image coordinates of a projection apparatus configured to project a pattern onto a measurement target object to perform a three-dimensional measurement, the information processing apparatus comprising:
one or more processors, and the one or more processors function as following units:
a decomposition unit configured to decompose respective variations of image coordinates in a plurality of images captured at different temperatures into parameters representing magnitudes of a plurality of predetermined movement components;
a calculation unit configured to calculate respective correction parameters for the decomposed parameters expressed in the plurality of predetermined movement components;
a derivation unit configured to derive, for each of the decomposed parameters expressed

Assignees

• Canon Kk

Inventors

• Kotake Daisuke
• Tohara Masakazu
• Yoshikawa Hiroshi

Classifications

• G01B5/0014

  due to temperature (on machine tools B23Q11/0003) · CPC title

• G01B11/2513

  with several lines being projected in more than one direction, e.g. grids, patterns · CPC title

• H04N13/254

  in combination with electromagnetic radiation sources for illuminating objects · CPC title

• H04N13/246 Primary

  Calibration of cameras · CPC title