# US 2013/0155417 A1 · Three-dimensional measurement apparatus, method for three-dimensional measurement, and computer program > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0155417 A1 - Document ID: US20130155417A1 - Status: Published application - Kind: A1 - Application number: 13/817,410 - Filed: 2011-08-05 - Published: 2013-06-20 - Earliest claimed: 2010-08-19 - Assignees: Canon Kabushiki Kaisha - Inventors: Hiroyuki Ohsawa - Web page: https://patentgrep.com/patent/US20130155417A1 ## CPC - 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}) - G01B 11/2536: {using several gratings with variable grating pitch, projected on the object with the same angle of incidence} - G06T 7/521: from laser ranging, e.g. using interferometry; from the projection of structured light - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract On the basis of captured images at the time of projecting multiple-frequency slit-shaped light patterns having no overlapping edge positions onto an object, the edge portions of the slit-shaped light patterns are identified. When the edge portions overlap in the captured images of two or more slit-shaped light patterns, the reliability of the computed distance values of the positions corresponding to the edges is lowered. ## Claims ### Claim 1 A three-dimensional measurement apparatus comprising: an obtaining unit configured to obtain a captured image of an object onto which pattern light having a light and dark stripe pattern is projected; an edge position detecting unit configured to detect an edge position indicating a boundary between light and dark portions of the pattern light in the captured image; an edge overlap degree detecting unit configured to detect a number of overlap of edge positions detected by the edge position detecting unit; and a position computing unit configured to compute a position of the object based on the edge positions and the number of overlap of the edge positions. ### Claim 2 (depends on 1) The three-dimensional measurement apparatus according to claim 1, wherein the light and dark stripe pattern is a Gray code. ### Claim 3 (depends on 1) The three-dimensional measurement apparatus according to claim 1, wherein the position computing unit computes the position of the object based on a pixel, in the captured image, in which the number of overlapping edge positions is one. ### Claim 4 (depends on 1) The three-dimensional measurement apparatus according to claim 1, wherein the position computing unit does not use a pixel, in the captured image, in which the number of overlapping edge positions is two or more for computation of the position of the object. ### Claim 5 (depends on 1) The three-dimensional measurement apparatus according to claim 1, wherein the edge position detecting unit, when the number of overlapping edge positions is two or more, detects the edge position of the light and dark stripe pattern through sub-pixel processing. ### Claim 6 (depends on 1) The three-dimensional measurement apparatus according to claim 1, further comprising a reliability computing unit configured to compute reliability of computing the position of the object based on the number of overlap of the edge positions. ### Claim 7 (depends on 6) The three-dimensional measurement apparatus according to claim 6, wherein the reliability computing unit does not output the position in which the reliability is below a reference. ### Claim 8 (depends on 6) The three-dimensional measurement apparatus according to claim 6, wherein the reliability computing unit determines a frequency of the light and dark stripe pattern based on the reliability. ### Claim 9 A three-dimensional measurement method comprising: an obtaining step of obtaining a captured image of an object onto which pattern light having a light and dark stripe pattern is projected; an edge position detecting step of detecting an edge position indicating a boundary between light and dark portions of the pattern light in the captured image; an edge overlap degree detecting step of detecting a number of overlap of the edge positions detected in the edge position detecting step; and a position computing step of computing a position of the object based on The edge positions and the number of overlap of the edge positions. ### Claim 10 A computer readable memory medium containing a computer program for causing a computer to execute: an obtaining step of obtaining a captured image of an object onto which pattern light having a light and dark stripe pattern is projected; an edge position detecting step of detecting an edge position indicating a boundary between light and dark portions of the pattern light in the captured image; an edge overlap degree detecting step of detecting a number of overlap of the edge positions detected in the edge position detecting step; and a position computing step of computing a position of the object based on the edge positions and the number of overlap of the edge positions.