Three-dimensional shape measuring apparatus and control method thereof

Abstract

An exposure amount of at least one or more first patterns used to determine positions at the time of triangulation is set to be larger than that of other patterns, so as to reduce the influence of shot noise in the first patterns, to improve precision, and to reduce power consumption as a whole. To this end, a three-dimensional shape measuring apparatus, which measures a three-dimensional shape of an object to be measured by projecting pattern light of a plurality of types of patterns onto the object to be measured, and capturing images of the object to be measured, controls a projector unit and image capture unit to set an exposure amount of the first patterns to be larger than that of patterns other than the first patterns.

1 - 10 . (canceled) 
     
     
         11 . A measurement apparatus for measuring a shape of a target region, the apparatus comprising:
 a projection unit configured to project, onto the target region, a first pattern and a second pattern different from the first pattern;   a capturing unit configured to capture the target region onto which the first pattern is projected and the target region onto which the second pattern is projected;   a control unit configured to control the capturing unit such that an exposure amount on the capturing unit when capturing the target region onto which the first pattern is projected is larger than an exposure amount on the capturing unit when capturing the target region onto which the second pattern is projected; and   a derivation unit configured to derive, based on a capturing result of the capturing unit, the shape of the target region by obtaining positions of points within the target region,   wherein the derivation unit decides, based on an image obtained by capturing the target region onto which the first pattern is projected, the positions of the points.   
     
     
         12 . The apparatus according to  claim 11 , wherein the control unit sets, by adjusting an exposure time of the capturing unit, the exposure amount on the capturing unit when capturing the target region onto which the first pattern is projected to be larger than the exposure amount on the capturing unit when capturing the target region onto which the second pattern is projected 
     
     
         13 . The apparatus according to  claim 11 , wherein the control unit controls the capturing unit such that the number of times of capturing operations of the target region onto which the first pattern is projected is larger than the number of times of capturing operations of the target region onto which the second pattern is projected, and
 wherein the derivation unit decides the positions of the points based on the capturing result obtained by combining capturing results of a plurality of capturing operations of the target region onto which the first pattern is projected, and by combining capturing results of a plurality of capturing operations of the target region onto which the second pattern is projected.   
     
     
         14 . The apparatus according to  claim 13 , wherein the control unit comprises a detection unit configured to detect outside-light components by capturing the target region by the capturing unit while the projection unit is set in an inactive state, and
 wherein after the detected outside-light components are subtracted from the capturing results of the plurality of capturing operations of the target region onto which the first pattern is projected, the capturing results of the plurality of capturing operations of the target region onto which the first pattern is projected are combined.   
     
     
         15 . The apparatus according to  claim 11 , wherein the first pattern includes first sub-patterns arranged in a first cycle, and the second pattern includes second sub-patterns arranged in a second cycle, the first cycle being shorter than the second cycle. 
     
     
         16 . The apparatus according to  claim 11 , wherein a finest sub-pattern among first sub-patterns included in the first pattern is finer than a finest sub-pattern among second sub-patterns included in the second pattern. 
     
     
         17 . The apparatus according to  claim 11 , wherein the derivation unit associates, using an image obtained by capturing the target region onto which the second pattern is projected, an image obtained by capturing the target region onto which the first pattern is projected with the image obtained by capturing the target region onto which the second pattern is projected. 
     
     
         18 . The apparatus according to  claim 11 , wherein the measurement apparatus is configured to measure a three-dimensional shape within the target region. 
     
     
         19 . The apparatus according to  claim 11 , wherein the points within the target region are discrete points within the target region. 
     
     
         20 . The apparatus according to  claim 11 , wherein the points within the target region are points which are observed within a predetermined region from the capturing unit. 
     
     
         21 . The apparatus according to  claim 11 , wherein the derivation unit derives three-dimensional positions of the points. 
     
     
         22 . A control method of a measurement apparatus for measuring a shape of a target region, the method comprising:
 projecting, onto the target region, a first pattern and a second pattern different from the first pattern;   capturing, by a capturing unit, the target region onto which the first pattern is projected and the target region onto which the second pattern is projected;   controlling the capturing unit such that an exposure amount on the capturing unit when capturing the target region onto which the first pattern is projected is larger than an exposure amount on the capturing unit when capturing the target region onto which the second pattern is projected; and   deriving, based on a capturing result of the capturing unit, the shape of the target region by obtaining positions of points within the target region,   wherein, based on an image obtained by capturing the target region onto which the first pattern is projected, the positions of the points are decided.   
     
     
         23 . A non-transitory computer-readable storage medium storing a computer program for causing a computer for measuring a shape of a target region to function as units comprising:
 a projection unit configured to project, onto the target region, a first pattern and a second pattern different from the first pattern;   a capturing unit configured to capture the target region onto which the first pattern is projected and the target region onto which the second pattern is projected;   a control unit configured to control the capturing unit such that an exposure amount on the capturing unit when capturing the target region onto which the first pattern is projected is larger than an exposure amount on the capturing unit when capturing the target region onto which the second pattern is projected; and   a derivation unit configured to derive, based on a capturing result of the capturing unit, the shape of the target region by obtaining positions of points within the target region,   wherein the derivation unit decides, based on an image obtained by capturing the target region onto which the first pattern is projected, the positions of the points.   
     
     
         24 . A measurement method of measuring a shape of a target region, the method comprising:
 projecting, onto the target region, a first pattern and a second pattern different from the first pattern;   capturing, by a capturing unit, the target region onto which the first pattern is projected and the target region onto which the second pattern is projected;   controlling the capturing unit such that an exposure amount on the capturing unit when capturing the target region onto which the first pattern is projected is larger than an exposure amount on the capturing unit when capturing the target region onto which the second pattern is projected; and   deriving, based on a capturing result of the capturing unit, the shape of the target region by obtaining positions of points within the target region,   wherein, based on an image obtained by capturing the target region onto which the first pattern is projected, the positions of the points are decided.