Information processing apparatus and method for measuring a target object

• US 9,857,166 B2
• Filed: 09/17/2013
• Issued: 01/02/2018
• Est. Priority Date: 09/19/2012
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Higo, Tomoaki, Ota, Kazuyuki
• Primary Examiner(s): Abraham, Samantha K
• Application Number:
  US14/029,116
• Publication Number:
  US 20140078490A1
• Time in Patent Office: 1,568 Days
• CPC Class Codes: G01B 11/25 by projecting a pattern, e.g. one or more lines, moiré fringes on the object G01B11/255 takes precedence ; image analysis for depth or shape recovery G06T7/50

Abstract

An information processing apparatus includes at least one projection unit configured to project a light pattern on a measuring target object, at least one imaging unit configured to capture an image of the measuring target object with the light pattern projected thereon, a measurement unit configured to measure a distance from the at least one projection unit or imaging unit to the measuring target object based on the image captured by the at least one imaging unit, a determination unit configured to determine whether a measured distance is valid, and a control unit configured to reduce luminance of a light pattern, included in a projected light pattern, which is projected on an area with respect to which the measured distance is determined by the determination unit to be valid.

Claims

1. An information processing apparatus comprising:

an obtaining unit configured to obtain a first image and a second image of a measuring target object with a light pattern projected thereon by a projection unit, wherein the first image and the second image are, respectively, captured by a first imaging unit and a second imaging unit disposed at a position different from a position of the first imaging unit;

a measurement unit configured to measure distance information about the measuring target object based on the first image and the second image captured by the first imaging unit and the second imaging unit, respectively;

a determination unit configured to determine that the measured distance information is valid in a case where a difference between first distance information about the measuring target object and second distance information about the measuring target object is within a predetermined threshold, the first distance information being measured based on the first image and the second distance information being measured based on the second image; and

a control unit configured to reduce luminance of a light pattern, included in a projected light pattern, which is projected on an area with respect to which the measured distance is determined by the determination unit to be valid.

2. The information processing apparatus according to claim 1, wherein the control unit is configured to perform control including reducing the luminance of the projected light pattern to zero.

3. The information processing apparatus according to claim 1, wherein the projected light pattern is a stripe pattern.

4. The information processing apparatus according to claim 1, wherein the projection unit is configured to sequentially project a plurality of light patterns on the measuring target object,

wherein the first imaging unit and the second imaging unit are each configured to sequentially capture an image of the measuring target object for each of the plurality of light patterns in a state where the plurality of light patterns is sequentially projected on the measuring target object,

wherein the measurement unit is configured to measure the first distance information and the second distance information about the measuring target object based on each image captured by the first and second imaging units, and

wherein the determination unit is configured to determine that the measured distance information is valid in a case where the difference between the first distance information and the second distance information is within a predetermined threshold.

5. The information processing apparatus according to claim 1, wherein the determination unit is configured to determine whether the distance information about the measuring target object, measured by the measurement unit, is valid further based on information relating to a shape of the measuring target object.

6. The information processing apparatus according to claim 1, further comprising a termination determination unit configured to determine whether a predetermined termination determination condition is satisfied, after processing in each unit defined by claim 1 is completed,

wherein, if the termination determination unit determines that the termination determination condition is not satisfied, processing in each unit defined by claim 1 is repeated.

7. The information processing apparatus according to claim 6, wherein the termination determination unit is configured to perform determination based on a number of repetitions with respect to sequential processing in units defined by claim 1.

8. The information processing apparatus according to claim 6, wherein the termination determination unit is configured to perform determination based on a time used to complete sequential processing in units defined by claim 1.

9. The information processing apparatus according to claim 6, wherein the termination determination unit is configured to perform determination based on a past measurement result and a present measurement result obtained by the determination unit.

10. The information processing apparatus according to claim 1, further comprising an acquisition unit configured to acquire a difficult-to-measure area, in which measuring the distance from the projection unit, the first imaging unit, or the second imaging unit to the measuring target object is difficult, based on the first image and the second image captured by the first imaging unit and the second imaging unit, respectively, wherein the difficult-to-measure area is at least one of an occlusion area where the measuring target object is concealed when the measuring target object is observed from the first imaging unit, the second imaging unit, or the projection unit and a saturation area where a luminance value in the captured image is saturated,

wherein the control unit is configured to reduce luminance of a light pattern, included in the projected light pattern, which is projected on the acquired difficult-to-measure area and luminance of a light pattern, included in the projected light pattern, which is projected on the area with respect to which the measured distance is determined by the determination unit to be valid.

11. The information processing apparatus according to claim 10, wherein the acquisition unit is configured to acquire a reliability of the distance information measured by the measurement unit based on a luminance value in each of the first image and the second image captured by the first imaging unit and the second imaging unit, respectively, and to acquire the difficult-to-measure area based on the acquired reliability.

12. The information processing apparatus according to claim 10, further comprising a termination determination unit configured to determine whether a predetermined termination determination condition is satisfied, after processing in each unit defined by claim 10 is completed,

wherein if the termination determination unit determines that the termination determination condition is not satisfied, processing in each unit defined by claim 1 is repeated.

13. The information processing apparatus according to claim 1, further comprising:

the projection unit configured to project a light pattern on the measuring target object, and

the first imaging unit and the second imaging unit each configured to capture a first image and a second image of the measuring target object, respectively.

14. The information processing apparatus according to claim 1, wherein the imaging conditions differ from one to another in the position of the projection unit projecting the light pattern.

15. The information processing apparatus according to claim 1, wherein the imaging conditions differ from one to another in the position of each of the first imaging unit and the second imaging unit capturing the measurement target object.

16. An information processing method comprising:

obtaining a first image and a second image of a measuring target object with a light pattern projected thereon by a projection unit, wherein the first image and the second image are, respectively, captured by a first imaging unit and a second imaging unit disposed at a position different from a position of the first imaging unit;

measuring distance information about the measuring target object based on the first image and the second image captured by the first imaging unit and the second imaging unit, respectively;

determining that the measured distance information is valid in a case where a difference between first distance information about the measuring target object and second distance information about the measuring target object is within a predetermined threshold, the first distance information being measured based on the first image and the second distance information being measured based on the second image; and

performing control to reduce luminance of a light pattern, included in the projected light pattern, which is projected on an area with respect to which the measured distance is determined to be valid.

17. A non-transitory computer readable storage medium storing a computer-executable program that causes a computer to perform an information processing method, wherein the information processing method comprising:

obtaining a first image and a second image of a measuring target object with the light pattern projected thereon by a projection unit, wherein the first image and the second image are, respectively, captured by a first imaging unit and a second imaging unit disposed at a position different from a position of the first imaging unit;

measuring distance information about the measuring target object based on the first image and the second image captured by the first imaging unit and the second imaging unit, respectively;

determining that the measured distance information is valid in a case where a difference between first distance information about the measuring target object and second distance information about the measuring target object is within a predetermined threshold, the first distance information being measured based on the first image and the second distance information being measured based on the second image; and

performing control to reduce luminance of a light pattern, included in the projected light pattern, which is projected on an area with respect to which the measured distance is determined to be valid.