# US 10,309,762 B2 · Reference coordinate system determination > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,309,762 B2 - Document ID: US10309762B2 - Status: Granted - Kind: B2 - Application number: 15/182,750 - Filed: 2016-06-15 - Published: 2016-10-13 - Granted: 2019-06-04 - Earliest claimed: 2012-11-02 - Assignees: QUALCOMM Incorporated - Applicants: QUALCOMM Incorporated - Inventors: Prince Gupta; Daniel Wagner; Gerhard Reitmayr; Alessandro Mulloni - Web page: https://patentgrep.com/patent/US10309762B2 ## CPC - G01B 11/002: {for measuring two or more coordinates} - G06T 7/70: Determining position or orientation of objects or cameras (camera calibration G06T7/80) - G06T 19/006: {Mixed reality (object pose determination, tracking or camera calibration for mixed reality G06T7/00)} - G06T 2207/10028: Range image; Depth image; 3D point clouds - 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 A method of determining a reference coordinate system includes: obtaining information indicative of a direction of gravity relative to a device; and converting an orientation of a device coordinate system using the direction of gravity relative to the device to produce the reference coordinate system. The method may also include setting an origin of the reference coordinate system and/or determining a scale value of the reference coordinate system. The method may also include refining the reference coordinate system. ## Claims ### Claim 1 A method of determining a reference coordinate system for use by a device, the method comprising: obtaining an image frame; determining a point cloud based on the image frame; and producing the reference coordinate system based on the point cloud by setting an origin of the reference coordinate system to a geometric center of a substantially planar portion of the point cloud. ### Claim 2 (depends on 1) The method of claim 1, further comprising calculating a scale value and wherein the reference coordinate system is produced using the scale value. ### Claim 3 (depends on 2) The method of claim 2, wherein the scale value is calculated based on the point cloud. ### Claim 4 (depends on 3) The method of claim 3, wherein calculating the scale value comprises comparing a dimension of the point cloud to a reference value. ### Claim 5 (depends on 2) The method of claim 2, wherein calculating the scale value comprises calculating the scale value such that an origin of the reference coordinate system will have a predetermined distance from the device. ### Claim 6 (depends on 2) The method of claim 2, wherein calculating the scale value comprises using absolute measurements from one or more input sensors of the device. ### Claim 7 (depends on 6) The method of claim 6, wherein the one or more input sensors comprise an accelerometer, or a plurality of cameras, or a combination thereof. ### Claim 8 A device for determining a reference coordinate system, the device comprising: means for obtaining an image frame; means for determining a point cloud based on the image frame; and means for producing the reference coordinate system based on the point cloud, including means for setting an origin of the reference coordinate system to a geometric center of a substantially planar portion of the point cloud. ### Claim 9 (depends on 8) The device of claim 8, further comprising means for calculating a scale value, wherein the means for producing the reference coordinate system uses the scale value. ### Claim 10 (depends on 9) The device of claim 9, wherein the means for calculating the scale value use the point cloud. ### Claim 11 (depends on 10) The device of claim 10, wherein the means for calculating the scale value comprises means for comparing a dimension of the point cloud to a reference value. ### Claim 12 (depends on 10) The device of claim 10, the means for calculating the scale value set an origin of the reference coordinate system a predetermined distance from the device. ### Claim 13 A mobile device comprising: a camera configured to obtain an image frame; and a processor, communicatively coupled to the camera, configured to: determine a point cloud based on the image frame; and produce the reference coordinate system based on the point cloud by setting an origin of the reference coordinate system to a geometric center of a substantially planar portion of the point cloud. ### Claim 14 (depends on 13) The mobile device of claim 13, wherein the processor is further configured to calculate a scale value based on the point cloud, and wherein the processor is further configured to produce the reference coordinate system using the scale value. ### Claim 15 A non-transitory processor-readable storage medium comprising processor-readable instructions configured to cause a processor of a device to: obtain an image frame; determine a point cloud based on the image frame; produce the reference coordinate system based on the point cloud; and set an origin of the reference coordinate system to a geometric center of a substantially planar portion of the point cloud. ### Claim 16 (depends on 15) The non-transitory processor-readable storage medium of claim 15, further comprising processor-readable instructions configured to calculate a scale value based on the point cloud, wherein the instructions configured to cause the processor to produce the reference coordinate system use the scale value.