# US 10,768,271 B2 · Distance or position determination > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,768,271 B2 - Document ID: US10768271B2 - Status: Granted - Kind: B2 - Application number: 14/899,693 - Filed: 2014-06-20 - Published: 2016-05-19 - Granted: 2020-09-08 - Earliest claimed: 2013-07-04 - Assignees: Signify Holding B.V. - Applicants: Signify Holding B.V. - Inventors: Koen Johanna Guillaume Holtman - Web page: https://patentgrep.com/patent/US10768271B2 ## CPC - G01S 5/16: using electromagnetic waves other than radio waves - G01C 21/206: {specially adapted for indoor navigation} - G01S 1/70: using electromagnetic waves other than radio waves - G01S 5/0009: {Transmission of position information to remote stations (involving assistance data G01S5/0236)} - G01S 11/12: using electromagnetic waves other than radio waves - H05B 47/125: by using cameras - H05B 47/165: following a pre-assigned programmed sequence; Logic control [LC] - H05B 47/19: via wireless transmission - H05B 47/1965: {using handheld communication devices} - Y02B 20/40: Control techniques providing energy savings, e.g. smart controller or presence detection - G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES - G01C: MEASURING DISTANCES, LEVELS OR BEARINGS; SURVEYING; NAVIGATION; GYROSCOPIC INSTRUMENTS; PHOTOGRAMMETRY OR VIDEOGRAMMETRY (measuring liquid level G01F; radio navigation, determining distance or velocity by use of propagation effects, e.g. Doppler effects, propagation time, of radio waves, analogous arrangements using other waves G01S) - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract A device, method and computer program for determining the distance or position of a camera relative to a light source based on an image of that light source captured by the camera. The device comprises a coded light detection module for detecting a coded light signal modulated into the light from the light source. The coded light detection module is configured to retrieve one or more physical dimensions of the light source based on the coded light signal from that light source. Further, the device comprises an image analysis module configured to determine a distance of the camera from the light source, by performing a geometric perspective calculation to compare the one or more retrieved physical dimensions with one or more apparent dimensions of the image of the light source. ## Claims ### Claim 1 A rangefinder device comprising: an input for receiving image data captured by a camera, the image data comprising an image of a light source; and at least one hardware processor configured to: detect a coded light signal modulated into light from the light source, and retrieve one or more physical dimensions of the light source based on the coded light signal from said light source, and determine a distance of the camera from the light source, by performing a geometric perspective calculation to compare the one or more retrieved physical dimensions with one or more apparent dimensions of the image of the light source. ### Claim 2 (depends on 1) The device of claim 1, wherein the one or more physical dimensions are communicated from the light source in the coded light signal, and the at least one hardware processor is configured to retrieve the one or more physical dimensions directly from the coded light signal. ### Claim 3 (depends on 1) The device of claim 1, wherein the coded light signal comprises an identifier of the light source, and the at least one hardware processor is configured to retrieve the one or more physical dimensions by using the identifier to look up the one or more physical dimensions in a data store. ### Claim 4 (depends on 1) The device of claim 1, configured to determine an orientation of the camera, wherein the distance and the orientation together give a position of the camera relative to the light source. ### Claim 5 (depends on 4) The device of claim 4, wherein the at least one hardware processor is configured to determine the orientation of the camera relative to the light source as part of the geometric perspective calculation. ### Claim 6 (depends on 4) The device of claim 4, wherein the light source is of a shape having a symmetry but emits light with a lighting effect that has an asymmetric lighting distribution, and the at least one hardware processor is configured to resolve ambiguity in the orientation based on said lighting effect. ### Claim 7 (depends on 6) The device of claim 6, wherein said lighting effect is imperceptible to human vision and perceptible to the camera, said light having said symmetry that is visible to a human, whilst the asymmetric lighting distribution is detected by the camera. ### Claim 8 (depends on 6) The device of claim 6, wherein said lighting effect comprises use of coded light to form said asymmetric lighting distribution. ### Claim 9 (depends on 4) The device of claim 4, configured to determine the absolute orientation of a viewpoint direction of the camera relative to a predetermined coordinate system, wherein the distance and the absolute orientation of the viewpoint direction of the camera are used to determine the position of the camera. ### Claim 10 (depends on 1) The device of claim 1, comprising a magnetometer configured to determine the absolute orientation of the viewpoint direction of the camera of the device relative to a predetermined coordinate system, which is then used to resolve an ambiguity in the orientation of the device with respect to the light source. ### Claim 11 (depends on 4) The device of claim 4, wherein the at least one hardware processor is configured to obtain a geographic location of the light source, and to determine a geographic location of the camera based on the geographic location of the light source combined with the position of the camera relative to the light source. ### Claim 12 (depends on 1) The device of claim 1, wherein the image data comprises an image of a single light source, the at least one hardware processor is configured to determine the distance of the camera from said single light source by performing the geometric perspective calculation to compare the one or more retrieved physical dimensions of the single light source with one or more apparent dimensions of the image of the single light source. ### Claim 13 (depends on 1) The device of claim 1, wherein the image data further comprises images of other objects, and the at least one hardware processor is configured to also include the images of the other objects in the geometric perspective calculation. ### Claim 14 (depends on 1) The device of claim 1, wherein the device comprises the camera. ### Claim 15 (depends on 1) The device of claim 1, wherein the one or more retrieved physical dimensions is one or more physical dimensions of a shape of the light source. ### Claim 16 A computer program product embodied on a computer readable non-transitory storage medium and configured, when executed on a processor, to implement a rangefinder device and perform operations of: receiving image data captured by a camera, the image data comprising an image of a light source; detecting a coded light signal modulated into the light from the light source; retrieving one or more physical dimensions of the light source based on the coded light signal from said light source; and determining a distance of the camera from the light source, by performing a geometric perspective calculation to compare the one or more retrieved physical dimensions with one or more apparent dimensions of the image of the light source. ### Claim 17 (depends on 16) The computer program product of claim 16, wherein the one or more retrieved physical dimensions is one or more physical dimensions of a shape of the light source.