Abstract: A method comprising: A) using a mobile device's camera to capture a first image; B) by reference to a first illumination source appearing in the first image, determining first heading information of the mobile device; C) as the mobile device moves to a second location, using one or more inertial sensors of the mobile device to extrapolate a plurality of extrapolated first candidate locations and respective first candidate headings of the mobile device; D) at the second location, using the camera to capture a second image; E) by reference to a second illumination source appearing in the second captured image, determining a plurality of second candidate locations and respective second candidate headings of the mobile device; and F) based on a comparison of the extrapolated first candidate locations and headings with the second candidate locations and headings, determining at least one estimated location and respective heading of the mobile device.

Abstract: A method comprising: A) using a mobile device's camera to capture a first image; B) by reference to a first illumination source appearing in the first image, determining first heading information of the mobile device; C) as the mobile device moves to a second location, using one or more inertial sensors of the mobile device to extrapolate a plurality of extrapolated first candidate locations and respective first candidate headings of the mobile device; D) at the second location, using the camera to capture a second image; E) by reference to a second illumination source appearing in the second captured image, determining a plurality of second candidate locations and respective second candidate headings of the mobile device; and F) based on a comparison of the extrapolated first candidate locations and headings with the second candidate locations and headings, determining at least one estimated location and respective heading of the mobile device.

Abstract: Multiple luminaires are mounted contiguously in a plane, along a straight line or following a one or two dimensional contour, but with a visible periphery between each adjacent pair. A different signal is embedded into the visible illumination emitted by each luminaire, which an image processing module can detect from one or more images captured by a camera. An angle-dependent mask is arranged to cover at least the periphery between adjacent luminaires, such that an appearance of the periphery when viewed from the environment through the mask varies as a function of viewing angle, becoming less visible at greater values of viewing angle (being the angle between a corresponding viewing direction and a normal to the plane, line or contour). The image processing module distinguishes between the different signals based on the periphery being visible when captured from less than a predetermined value of the viewing angle.

Abstract: An apparatus, method and program for receiving a coded light signal comprising a periodically repeating message repeating with a message period. A portion of the message is received in each of a plurality of frames captured by a rolling-shutter camera, with different portions being received in different frames. Using each of a discrete group of trial values of the message period, the respective trial value is used to reconstruct a respective first version of the message from the portions received in a first subset of said frames, and to reconstruct a respective second version of the message from the portions received in a second subset of said frames. For each of the trial values, there is generate a respective value of a measure of similarity between the respective reconstructed first and second versions of the message. An estimate of the message period is determined based on this.

Abstract: Multiple luminaires are mounted contiguously in a plane, along a straight line or following a one or two dimensional contour, but with a visible periphery between each adjacent pair. A different signal is embedded into the visible illumination emitted by each luminaire, which an image processing module can detect from one or more images captured by a camera. An angle-dependent mask is arranged to cover at least the periphery between adjacent luminaires, such that an appearance of the periphery when viewed from the environment through the mask varies as a function of viewing angle, becoming less visible at greater values of viewing angle (being the angle between a corresponding viewing direction and a normal to the plane, line or contour). The image processing module distinguishes between the different signals based on the periphery being visible when captured from less than a predetermined value of the viewing angle.

Abstract: An apparatus, method and program for receiving a coded light signal comprising a periodically repeating message repeating with a message period. A portion of the message is received in each of a plurality of frames captured by a rolling-shutter camera, with different portions being received in different frames. Using each of a discrete group of trial values of the message period, the respective trial value is used to reconstruct a respective first version of the message from the portions received in a first subset of said frames, and to reconstruct a respective second version of the message from the portions received in a second subset of said frames. For each of the trial values, there is generate a respective value of a measure of similarity between the respective reconstructed first and second versions of the message. An estimate of the message period is determined based on this.

Abstract: The invention relates to an apparatus, a system and a method of locating a location of a portable device using coded light, the portable device comprising an image sensor and an inertial measurement unit, the method comprising: obtaining a first image comprising the coded light source from the image sensor and substantially simultaneously obtaining orientation information indicative of the orientation of the portable device or the image sensor from the inertial measurement unit; obtaining light source specific information in the form of: an identifier that allows retrieval of a three-dimensional location of the coded light source or a three-dimensional location of the coded light source; and computing the location of the portable device or image sensor based on the orientation information, a predetermined height estimate of the portable device or image sensor and the light source specific information.

Abstract: The invention relates to an apparatus, a system and a method of locating a location of a portable device using coded light, the portable device comprising an image sensor and an inertial measurement unit, the method comprising: obtaining a first image comprising the coded light source from the image sensor and substantially simultaneously obtaining orientation information indicative of the orientation of the portable device or the image sensor from the inertial measurement unit; obtaining light source specific information in the form of: an identifier that allows retrieval of a three-dimensional location of the coded light source or a three-dimensional location of the coded light source; and computing the location of the portable device or image sensor based on the orientation information, a predetermined height estimate of the portable device or image sensor and the light source specific information.