Measurement system and measurement method

Patent metadata

Field	Value
Publication number	US-11023706-B2
Application number	US-201916413619-A
Country	US
Kind code	B2
Filing date	May 16, 2019
Priority date	Jun 20, 2018
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

A measurement system includes a first distance calculation unit that searches for a corresponding region, indicating a same array as an array of codes indicated by a predetermined number of reference patterns included in a unit region set in the projection pattern, from a set of the codes, and calculates a distance from an irradiation reference surface of the projection pattern to each portion of the object on the basis of a search result of the corresponding region, and a second distance calculation unit that attempts to estimate a distance for the defective portion for which the first distance calculation unit is not able to calculate the distance by reconstructing an incomplete code corresponding to the defective portion using peripheral information in the input image.

First claim

What is claimed is:

1. A measurement system comprising:
an acquisition unit comprising a first processor configured to acquire an input image which is an image obtained by imaging an object in a state where the object is irradiated with a projection pattern determined in advance, the projection pattern being configured with a plurality of types of reference patterns to which specific codes are assigned in accordance with a predetermined rule; and
an image measuring device comprising a second processor, configured to
search for each reference pattern included in the radiated projection pattern within the input image from the acquisition unit to acquire a position at which each reference pattern is radiated and a set of codes indicated by the radiated reference pattern,
search for a corresponding region, indicating a same array as an array of codes indicated by a predetermined number of reference patterns included in a unit region set in the projection pattern, from a set of the codes,
calculate a first distance from an irradiation reference surface of the projection pattern to each portion of the object on the basis of a search result of the corresponding region,
attempt to estimate a second distance for a defective portion for which the first distance is not able to be calculated by reconstructing an incomplete code corresponding to the defective portion using peripheral information in the input image, and
generate a virtual background image to be captured in a case where the projection pattern is radiated from the irradiation reference surface to a plane surface located at an arbitrary distance or a virtual background image code corresponding to the virtual background image,
wherein the image measuring device attempts to estimate the second distance for the defective portion using information of the input image corresponding to the defective portion and the virtual background image or the virtual background image code.

2. The measurement system according to claim 1 , wherein the image measuring device synthesizes a corresponding partial pattern of the virtual background image with a portion corresponding to the defective portion of the input image or a vicinity of the corresponding portion,
wherein the image measuring device attempts to search for the corresponding region while sequentially changing at least one of the partial pattern of the virtual background image synthesized with the input image and a distance for a plane surface when the virtual background image is generated.

3. The measurement system according to claim 1 ,
wherein the image measuring device repeats a process of searching for a same array as an array of codes indicated by a predetermined number of reference patterns included in a unit region set in the projection pattern with respect to one or a plurality of code strings generated by a combination of at least a portion of a code searched for in a portion corresponding to the defective portion of the input image and a code to which the virtual background image code corresponds.

4. The measurement system according to claim 1 ,
wherein the image measuring device generates a plurality of the virtual background images or the virtual background image codes with respect to plane surfaces located at a plurality of different distances from the irradiation reference surface.

5. The measurement system according to claim 1 ,
wherein the image measuring device changes a positional relationship between the information of the input image corresponding to the defective portion and the virtual background image or the virtual background image code along an epipolar line.

6. The measurement system according to claim 1 ,
wherein the image measuring device determines that estimation of the second distance for the defective portion is successful in a case where the estimated second distance for the defective portion is different from a distance when the virtual background image or the virtual background image code used in the estimation is generated.

7. A measurement method, comprising steps of:
acquiring an input image which is an image obtained by imaging an object in a state where the object is irradiated with a projection pattern determined in advance, the projection pattern being configured with a plurality of types of reference patterns to which specific codes are assigned in accordance with a predetermined rule;
searching for each reference pattern included in the radiated projection pattern within the input image to acquire a position at which each reference pattern is radiated and a set of codes indicated by the radiated reference pattern,
searching for a corresponding region, indicating a same array as an array of codes indicated by a predetermined number of reference patterns included in a unit region set in the projection pattern, from a set of the codes,
calculating a first distance from an irradiation reference surface of the projection pattern to each portion of the object on the basis of a search result of the corresponding region,
attempting to estimate a second distance for a defective portion for which the first distance is not able to be calculated by reconstructing an incomplete code corresponding to the defective portion using peripheral information in the input image,
generating a virtual background image to be captured in a case where the projection pattern is radiated from the irradiation reference surface to a plane surface located at an arbitrary distance or a virtual background image code corresponding to the virtual background image, and
attempting to estimate the second distance for the defective portion using information of the input image corresponding to the defective portion and the virtual background image or the virtual background image code.

8. The measurement system according to claim 2 ,
wherein the image measuring device generates a plurality of the virtual background images or the virtual background image codes with respect to plane surfaces located at a plurality of different distances from the irradiation reference surface.

9. The measurement system according to claim 3 ,
wherein the image measuring device generates a plurality of the virtual background images or the virtual background image codes with respect to plane surfaces located at a plurality of different distances from the irradiation reference surface.

10. The measurement system according to claim 2 ,
wherein the image measuring device changes a positional relationship between the information of the input image corresponding to the defective portion and the virtual background image or the virtual background image code along an epipolar line.

11. The measurement system according to claim 3 ,
wherein the image measuring device changes a positional relationship between the information of the input image corresponding to the defective portion and the virtual background image or the virtual background image code along an epipolar line.

12. The measurement system according to claim 2 ,
wherein the image measuring device changes a positional relationship between the information of the input image corresponding to the defective portion and the virtual background image or the virtual background image code along an epipolar line.

13. The measurement system according to claim 3 ,
wherein the image measuring device determines that estimation of the second distance for the defective portion is successful in a case where the estimated second distance for the defective portion is different from a distance when the virtual background image or the virtual background image code used in the estimation is generated.

14. Th

Assignees

• Omron Tateisi Electronics Co

Inventors

• Nakatsuka Hitoshi
• Iida Toyoo

Classifications

• G06T7/521 Primary

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

• G06V20/64 Primary

  Three-dimensional [3D] objects · CPC title

• G01C3/085

  with electronic parallax measurement · CPC title

• G06T2207/30184

  Infrastructure · CPC title

• G01C3/08

  Use of electric radiation detectors · CPC title