# US 10,310,922 B2 · Systems and methods for predicting and improving scanning geometric accuracy for 3D scanners > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,922 B2 - Document ID: US10310922B2 - Status: Granted - Kind: B2 - Application number: 15/098,267 - Filed: 2016-04-13 - Published: 2016-10-13 - Granted: 2019-06-04 - Earliest claimed: 2015-04-13 - Assignees: University of Southern California - Applicants: University of Southern California - Inventors: Qiang Huang - Web page: https://patentgrep.com/patent/US10310922B2 ## CPC - G06F 11/0721: {within a central processing unit [CPU]} - G01B 11/24: for measuring contours or curvatures - H04N 1/00: Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof - H04N 13/00: Stereoscopic video systems; Multi-view video systems; Details thereof - H04N 13/204: using stereoscopic image cameras (stereoscopic photography G03B35/00) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G01B: MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract Methods, systems, and apparatus including medium-encoded computer program products for generating and visualizing 3D scenes include, in one aspect, a method including: obtaining data regarding (i) standard calibration parts with shapes comprising a cylinder and polyhedrons, and (ii) a limited number of scanning trials performed on the standard calibration parts using a three dimensional (3D) scanner; comparing the data to find shape deviations for the standard calibration parts in a coordinate system; generating a model of functional dependence of scanning error for the 3D scanner using the shape deviations; and providing the model of functional dependence of scanning error for the 3D scanner to quantify scanning inaccuracy of the 3D scanner, wherein the model is usable to predict a measurement error for the 3D scanner on a scanned product. ## Claims ### Claim 1 A method performed by a computer system comprising processor electronics and at least one memory device, the method comprising: obtaining data regarding (i) standard calibration parts with shapes comprising cylinders and polyhedrons, and (ii) one or more scanning trials performed on the standard calibration parts using a three dimensional (3D) scanner; comparing the data to find shape deviations for the standard calibration parts in a coordinate system; generating a model of functional dependence of scanning error for the 3D scanner using the shape deviations, wherein the model includes a first function base representing the shape deviations of cylindrical shape, and a second function representing a cookie-cutter model connecting the cylindrical shape with one or more different shapes; and providing the model of functional dependence of scanning error for the 3D scanner to quantify scanning inaccuracy of the 3D scanner, wherein the model is usable to predict a measurement error for the 3D scanner on a scanned product. ### Claim 2 (depends on 1) The method of claim 1, wherein obtaining the data regarding the one or more scanning trials comprises: taking photographic images of a standard calibration part from different angles using the 3D scanner; and fusing the photographic images together to generate a digital model of the standard calibration part. ### Claim 3 (depends on 1) The method of claim 1, wherein generating the model of functional dependence of scanning error for the 3D scanner comprises extracting location-independent shape deviation pattern and location-dependent shape deviation pattern for the cylindrical base function. ### Claim 4 (depends on 1) The method of claim 1, wherein generating the model of functional dependence of scanning error for the 3D scanner comprises using a cookie-cutter model to trim a polygon from a cylinder. ### Claim 5 (depends on 4) The method of claim 4, wherein generating the model of functional dependence of scanning error for the 3D scanner comprises using a library of cookie-cutter models including a square wave model and a sawtooth wave model. ### Claim 6 (depends on 1) The method of claim 1, comprising: obtaining a digital model of the scanned product, which has been scanned using the 3D scanner; predicting the measurement error for the 3D scanner on the scanned product using the model of functional dependence of scanning error for the 3D scanner to predict geometric discrepancies generated by the 3D scanner; and adjusting of the digital model using the predicted measurement error for the 3D scanner on the scanned product. ### Claim 7 (depends on 1) The method of claim 1, wherein generating the model of functional dependence of scanning error for the 3D scanner comprises using a Polar Coordinate System (PCS) in which each of the shape deviations represents geometric errors in a plane as a functional profile defined on an interval of the PCS corresponding to an angular location variable. ### Claim 8 (depends on 1) The method of claim 1, wherein the cookie-cutter model connecting the cylindrical shape with one or more different shapes extends the first function base to a freeform for arbitrary shapes. ### Claim 9 (depends on 1) The method of claim 1, wherein generating the model of functional dependence of scanning error for the 3D scanner comprises using a Spherical Coordinate System (SC S) in which each of the shape deviations represents geometric errors as a functional surface defined on an interval of the SCS corresponding to two angular location variables. ### Claim 10 A method performed by a computer system comprising processor electronics and at least one memory device, the method comprising: obtaining data regarding (i) standard calibration parts with shapes comprising cylinders and polyhedrons, and (ii) one or more scanning trials performed on the standard calibration parts using a three dimensional (3D) scanner; comparing the data to find shape deviations for the standard calibration parts in a Polar Coordinate System (PCS), wherein each of the shape deviations represents geometric errors as a functional profile defined on an interval of the PCS corresponding to an angular location variable; generating a model of functional dependence of scanning error for the 3D scanner using the shape deviations, wherein the model includes a first function base representing the shape deviations of cylindrical shape, and a second function representing a cookie-cutter model connecting the cylindrical shape with one or more different shapes; and providing the model of functional dependence of scanning error for the 3D scanner to quantify scanning inaccuracy of the 3D scanner, wherein the model is usable to predict a measurement error for the 3D scanner on a scanned product. ### Claim 11 (depends on 10) The method of claim 10, wherein obtaining the data regarding the one or more scanning trials comprises: taking photographic images of a standard calibration part from different angles using the 3D scanner; and fusing the photographic images together to generate a digital model of the standard calibration part. ### Claim 12 (depends on 10) The method of claim 10, wherein generating the model of functional dependence of scanning error for the 3D scanner comprises extracting location-independent shape deviation pattern and location-dependent shape deviation pattern for the cylindrical base function. ### Claim 13 (depends on 10) The method of claim 10, wherein generating the model of functional dependence of scanning error for the 3D scanner comprises using a cookie-cutter model to trim a polygon from a cylinder. ### Claim 14 (depends on 13) The method of claim 13, wherein generating the model of functional dependence of scanning error for the 3D scanner comprises using a library of cookie-cutter models including a square wave model and a sawtooth wave model. ### Claim 15 (depends on 1) The method of claim 1, comprising: obtaining a digital model of the scanned product, which has been scanned using the 3D scanner; predicting the measurement error for the 3D scanner on the scanned product using the model of functional dependence of scanning error for the 3D scanner to predict geometric discrepancies generated by the 3D scanner; and adjusting of the digital model using the predicted measurement error for the 3D scanner on the scanned product. ### Claim 16 (depends on 15) The method of claim 15, wherein adjusting of the digital model comprises determining an optimal compensation algorithm for scanning error of a 3D scanner. ### Claim 17 A system comprising: a three-dimensional (3D) scanner; and one or more computing devices coupled with the 3D scanner and programmed to (i) obtain data regarding (a) standard calibration parts with shapes comprising cylinders and polyhedrons, and (b) one or more scanning trials performed on the standard calibration parts using the three dimensional (3D) scanner; (ii) compare the data to find shape deviations for the standard calibration parts in a coordinate system; (iii) generate a model of functional dependence of scanning error for the 3D scanner using the shape deviations, wherein the model includes a first function base representing the shape deviations of cylindrical shape, and a second function representing a cookie-cutter model connecting the cylindrical shape with one or more different shapes; and (iv) provide the model of functional dependence of scanning error for the 3D scanner to quantify scanning inaccuracy of the 3D scanner, wherein the model is usable to predict a measurement error for the 3D scanner on a scanned product.