# US 8,786,682 B2 · Reference image techniques for three-dimensional sensing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,786,682 B2 - Document ID: US8786682B2 - Status: Granted - Kind: B2 - Application number: 12/707,678 - Filed: 2010-02-18 - Published: 2010-09-09 - Granted: 2014-07-22 - Earliest claimed: 2009-03-05 - Assignees: Primesense Ltd. - Applicants: Alexander Shpunt; Dmitri Rais; Niv Galezer - Inventors: Alexander Shpunt; Dmitri Rais; Niv Galezer - Web page: https://patentgrep.com/patent/US8786682B2 ## CPC - H04N 13/218: using spatial multiplexing - G01B 11/2518: {Projection by scanning of the object} - G01B 11/2545: {with one projection direction and several detection directions, e.g. stereo} - G06T 1/0007: {Image acquisition} - G06T 7/521: from laser ranging, e.g. using interferometry; from the projection of structured light - G06V 10/145: Illumination specially adapted for pattern recognition, e.g. using gratings - H04N 13/254: in combination with electromagnetic radiation sources for illuminating objects - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION - 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 - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING ## Abstract A method including providing a device that projects a pattern of coherent radiation. The method further includes capturing a reference image of the pattern using an image sensor by projecting the pattern of the coherent radiation onto a reference surface and engendering a relative motion between the reference surface and the image sensor while capturing the reference image. The method also includes storing the reference image in a memory associated with the device. ## Claims ### Claim 1 A method for three-dimensional mapping, comprising: providing a mapping device, which comprises: a projector configured to project a pattern onto an object; a first image sensor, which has a first optical characteristic and is configured to capture images of the object on which the pattern is projected; a memory configured to store a reference image of the pattern; and a processor configured to measure shifts in the pattern in the images relative to the stored reference image in order to generate a three-dimensional (3D) map of the object; generating the reference image in a production facility by: operating the mapping device so as to project the pattern onto a reference surface, prior to projecting the pattern onto the object; capturing a second image of the pattern on the reference surface using a second image sensor, which is external to and separate from the mapping device and has a second optical characteristic that is enhanced relative to the first optical characteristic; and registering the first and second images to produce the reference image, which is registered in a frame of reference of the projection and imaging device, wherein registering the first and second images comprises identifying and correlating features common to the first and second images in order to find local transformations, and then combining the local transformations to apply a global transformation to the second image in order to produce the reference image; storing the reference image produced by registering the first and second images in the memory of the mapping device; and generating the 3D map using the mapping device by projecting the pattern onto the object, capturing the images of the object using the first image sensor, and measuring the shifts in the pattern relative to the stored reference image. ### Claim 2 (depends on 1) The method according to claim 1, wherein the pattern is projected using incoherent radiation. ### Claim 3 (depends on 1) The method according to claim 1, wherein the enhanced optical characteristic comprises an enhanced field of view. ### Claim 4 (depends on 1) The method according to claim 1, wherein the enhanced optical characteristic comprises an enhanced resolution. ### Claim 5 (depends on 1) The method according to claim 1, wherein the enhanced optical characteristic comprises an enhanced signal to noise ratio. ### Claim 6 (depends on 1) The method according to claim 1, wherein the enhanced optical characteristic comprises an enhanced dynamic range. ### Claim 7 Apparatus, comprising: a mapping device comprising: a projector configured to project a pattern onto an object; a first image sensor, which has a first optical characteristic and is configured to capture images of the object on which the pattern is projected; a memory configured to store a reference image of the pattern; and a processor configured to measure shifts in the pattern in the images relative to the stored reference image in order to generate a three-dimensional (3D) map of the object; and an assembly for generating the reference image in a production facility, comprising: a second image sensor, which is external to and separate from the mapping device and has a second optical characteristic that is enhanced relative to the first optical characteristic, wherein the mapping device is operated in the production facility, prior to projecting the pattern onto the object, to project the pattern onto a reference surface and to capture a first image of the pattern projected onto the reference surface using the first image sensor, and wherein the second image sensor is configured to capture a second image of the pattern projected by the projector onto the reference surface; and a processing unit, which is configured to register the first and second images to produce the reference image, which is registered in a frame of reference of the projection and imaging device, wherein registering the first and second images comprises identifying and correlating features common to the first and second images in order to find local transformations, and then combining the local transformations to apply a global transformation to the second image in order to produce the reference image; wherein the processor is configured to store the reference image produced by registering the first and second images in the memory of the mapping device. ### Claim 8 (depends on 7) The apparatus according to claim 7, wherein the pattern is projected using incoherent radiation. ### Claim 9 (depends on 7) The apparatus according to claim 7, wherein the enhanced optical characteristic comprises an enhanced field of view. ### Claim 10 (depends on 7) The apparatus according to claim 7, wherein the enhanced optical characteristic comprises an enhanced resolution. ### Claim 11 (depends on 7) The apparatus according to claim 7, wherein the enhanced optical characteristic comprises an enhanced signal to noise ratio. ### Claim 12 (depends on 7) The apparatus according to claim 7, wherein the enhanced optical characteristic comprises an enhanced dynamic range.