INFORMATION PROCESSING APPARATUS AND METHOD FOR MEASURING A TARGET OBJECT

• US 20140078490A1
• Filed: 09/17/2013
• Published: 03/20/2014
• Est. Priority Date: 09/19/2012
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Ota, Kazuyuki, Higo, Tomoaki
• Granted Patent: US 9,857,166 B2
• Time in Patent Office: Days
• US Class Current: 356/4.01
• 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:

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 the at least one 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.

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, further comprising a plurality of the at least one projection unit and the at least one imaging unit,

wherein the measurement unit is configured to measure a distance from each projection unit or each imaging unit to the measuring target object, and

wherein the determination unit is configured to determine whether the measured distance is valid by checking a coincidence between distances measured based on images captured using the plurality of the at least one projection unit and the at least one imaging unit.

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

wherein the at least one imaging unit is 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 a distance between from the at least one projection unit or the at least one imaging unit to the measuring target object for each image based on each captured image, and

wherein the determination unit is configured to determine whether the measured distance is valid by checking a coincidence between distances measured based on the captured images.

6. The information processing apparatus according to claim 1, wherein the determination unit is configured to determine whether the distance from the at least one imaging unit or the at least one projection unit to the measuring target object, measured by the measurement unit, is valid based on information relating to a shape of the measuring target object.

7. 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, sequential processing to be performed by the at least one projection unit, the at least one imaging unit, the measurement unit, the determination unit, and the control unit is repeated at least once.

8. The information processing apparatus according to claim 7, wherein the termination determination unit is configured to perform determination based on a number of repetitions with respect to sequential processing performed by the at least one projection unit, the at least one imaging unit, the measurement unit, the determination unit, and the control unit.

9. The information processing apparatus according to claim 7, wherein the termination determination unit is configured to perform determination based on a time used to complete sequential processing to be performed by the at least one projection unit, the at least one imaging unit, the measurement unit, the determination unit, and the control unit.

10. The information processing apparatus according to claim 7, wherein the termination determination unit is configured to perform determination based on a number of valid measurement points in a predetermined area processed by the at least one projection unit, the at least one imaging unit, the measurement unit, the determination unit, and the control unit.

11. The information processing apparatus according to claim 7, wherein the termination determination unit is configured to perform determination based on a past measurement result and a present measurement result obtained by the at least one projection unit, the at least one imaging unit, the measurement unit, the determination unit, and the control unit.

12. 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 at least one projection unit or imaging unit to the measuring target object is difficult, based on the image captured by the at least one imaging unit,

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.

13. The information processing apparatus according to claim 12, 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 at least one imaging unit or the at least one projection unit and a saturation area where a luminance value in the captured image is saturated.

14. The information processing apparatus according to claim 12, wherein the acquisition unit is configured to acquire a reliability of the distance measured by the measurement unit based on the image captured by the at least one imaging unit and to acquire the difficult-to-measure area based on the acquired reliability.

15. The information processing apparatus according to claim 12, 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 12 is completed,

wherein if the termination determination unit determines that the termination determination condition is not satisfied, sequential processing to be performed by the at least one projection unit, the at least one imaging unit, the acquisition unit, the measurement unit, the determination unit, and the control unit is repeated at least once.

16. The information processing apparatus according to claim 12, wherein the control unit is configured to temporarily 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, in a case where sequential processing by the at least one projection unit, the at least one imaging unit, the acquisition unit, the measurement unit, the determination unit, and the control unit is repetitively performed a predetermined number of times.

17. An information processing method comprising:

projecting, via a projection unit, a light pattern on a measuring target object;

capturing, via an imaging unit, an image of the measuring target object with the light pattern projected thereon;

measuring a distance from the projection unit or the imaging unit to the measuring target object based on the captured image;

determining whether the measured distance is valid; 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.

18. 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:

projecting, via a projection unit, a light pattern on a measuring target object;

capturing, via an imaging unit, an image of the measuring target object with the light pattern projected thereon;

measuring a distance from the projection unit or the imaging unit to the measuring target object based on the captured image;

determining whether the measured distance is valid; 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.