Abstract: A system comprising: a plurality of first devices, each configured to transmit a low-frequency, LF, light signal comprising an identifier of the respective first device, and to transmit and/or receive a high-frequency, HF, light signal comprising data content; and a second device configured to receive a LF light signal from each of the first devices, and to transmit and/or receive a HF light signal from at least one first device, wherein the second device has an adaptable receiving and/or transmitting direction for respectively receiving and/or transmitting the HF light signal, and wherein the second device comprises a controller configured to: based on the identifiers encoded in the LF light signals, determine a position of the second device relative to the first devices and select a first device; and based on the determination, adapt the receiving and/or transmitting direction toward the selected first device.

Abstract: The invention relates to a system and methods for providing conditional access to indoor location information in a system comprising a mobile device (320), a positioning webservice (310) and an authorization authority (360), the method comprising: the mobile device (320) performing the steps of: transmitting license information to the authorization authority (360) and transmitting a request for indoor location information to the positioning webservice, the request comprising a request-location-estimate corresponding to a location estimate of the mobile device (320) at the time of making the request, the authorization authority (360) performing the steps of: receiving the license information, verifying whether the license information authorizes access to indoor location information by the mobile device (320), issuing a secure proof, verifiable by the positioning webservice (310) upon successful verification, the secure proof indicating that the license information authorizes access to indoor location informati

Abstract: A system comprising: a plurality of first devices, each configured to transmit a low-frequency, LF, light signal comprising an identifier of the respective first device, and to transmit and/or receive a high-frequency, HF, light signal comprising data content; and a second device configured to receive a LF light signal from each of the first devices, and to transmit and/or receive a HF light signal from at least one first device, wherein the second device has an adaptable receiving and/or transmitting direction for respectively receiving and/or transmitting the HF light signal, and wherein the second device comprises a controller configured to: based on the identifiers encoded in the LF light signals, determine a position of the second device relative to the first devices and select a first device; and based on the determination, adapt the receiving and/or transmitting direction toward the selected first device.

Abstract: A device is provided having: a camera for capturing an image by capturing a repetitive series of a set of frames; wherein the camera comprises a first group of camera settings associated with detecting Visible Light Communication and a second group of camera settings not associated with detecting Visible Light Communication; wherein said set of frames comprises a first subset of frames and a second subset of frames, wherein each subset comprises at least one frame; a processor configured to switch the camera periodically between the first group of camera settings and the second group of camera settings for capturing the image by capturing each first subset of frames of the repetitive series of the set of frames with the first group of camera settings and each second subset of frames of the repetitive series of the set of frames with the second group of camera settings.

Abstract: A method, program and apparatus for detecting a repeating coded light message embedded in light emitted by a light source, based on images captured from rolling-shutter cameras which capture their frame areas line-but-line. Images of the light source are captured simultaneously using a plurality of different rolling-shutter cameras having different acquisition regimes in order to improve the robustness and/or speed of coded light detection. The different acquisition regimes may comprise different frame rates, different physical orientations, or different line-readout directions.

Abstract: A series of frames is captured by a rolling-shutter camera, each frame capturing an image of a light source which has a periodic message embedded in its light. With a rolling-shutter camera, each line captures a respective sample of the message and each frame captures a respective fragment of the message made up of a respective subsequence of the samples, wherein the message can be reconstructed from the fragments captured over multiple frames. Further, the frame rate of the rolling-shutter camera is dependent on a region of interest (ROI), and the method further comprises evaluating a metric indicative of how long will be required to accumulate enough fragments to reconstruct the message at the current frame rate, and adapting the ROI in dependence on this metric in order to change the frame rate and thereby reduce the number of subsequent frames required to complete the reconstruction of the message.

Abstract: The invention provides a device for image based services.

Abstract: The invention relates to a system and methods for providing conditional access to indoor location information in a system comprising a mobile device (320), a positioning webservice (310) and an authorization authority (360), the method comprising: the mobile device (320) performing the steps of: transmitting license information to the authorization authority (360) and transmitting a request for indoor location information to the positioning webservice, the request comprising a request-location-estimate corresponding to a location estimate of the mobile device (320) at the time of making the request, the authorization authority (360) performing the steps of: receiving the license information, verifying whether the license information authorizes access to indoor location information by the mobile device (320), issuing a secure proof, verifiable by the positioning webservice (310) upon successful verification, the secure proof indicating that the license information authorizes access to indoor location informati

Abstract: A method, program and apparatus for detecting a repeating coded light message embedded in light emitted by a light source, based on images captured from rolling-shutter cameras which capture their frame areas line-but-line. Images of the light source are captured simultaneously using a plurality of different rolling-shutter cameras having different acquisition regimes in order to improve the robustness and/or speed of coded light detection. The different acquisition regimes may comprise different frame rates, different physical orientations, or different line-readout directions.

Abstract: The invention relates to a system and methods for providing conditional access to indoor location information in a system comprising a mobile device (320), a positioning webservice (310) and an authorization authority (360), the method comprising: the mobile device (320) performing the steps of: transmitting license information to the authorization authority (360) and transmitting a request for indoor location information to the positioning webservice, the request comprising a request-location-estimate corresponding to a location estimate of the mobile device (320) at the time of making the request, the authorization authority (360) performing the steps of: receiving the license information, verifying whether the license information authorizes access to indoor location information by the mobile device (320), issuing a secure proof, verifiable by the positioning webservice (310) upon successful verification, the secure proof indicating that the license information authorizes access to indoor location informati

Abstract: A method for calibrating an ambience lighting system for providing an ambient light effect for a cinema display screen is proposed. The method is based on implementing the ambience lighting system in the form of one or more of coded light (CL) sources. The method then includes processing one or more images of a scene being illuminated by the ambience lighting system to determine, based on the CL embedded into the light output of the individual CL sources, color and/or an intensity of the light generated by the individual CL source. The set of control data for controlling the CL sources to provide the desired ambient light effect is then based not only on the color and/or intensity of image content to be displayed on the cinema display screen, but also on the determined color and/or intensity of the light output of the individual CL sources.

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: 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: The visible illumination emitted by each of some or all of an arrangement of contiguously-mounted lighting units is temporally modulated to embed a different respective signal into the illumination emitted by each. A camera captures one or more images of the data-transmitting luminous areas of one or more of these lighting units, from which are detected the respective signals. The system is further configured to spatially modulate at least part of the light emitted by one or more of the lighting units of the arrangement with a spatial pattern. The detection comprises distinguishing each of the one or more data-transmitting lighting units from amongst the multiple data-transmitting lighting units based on an auto correlation of the spatial pattern.

Abstract: A device comprising an input for receiving image data representing light captured by a camera, and an image analysis module for detecting a coded light component modulated into the light with a modulation frequency. The camera has an exposure time, and the light is captured over a sequence of exposures each lasting for an instance of the exposure time. The detection performed by the image analysis module experiences a frequency blind spot in said detection due to an effect of said exposure time. To address this issue, the device further comprises an output for controlling one or more parameters of the camera which affect the exposure time, and a controller configured to control the one or more parameters to avoid that the modulation frequency corresponds to the frequency blind spot.

Abstract: The invention provides a communication system (500), a lighting system, a method of transmitting information and a computer program product. The communication system according to the invention is configured for transmitting data via visible light. The communication system comprises a signal generator (530) for generating a light driving signal (200) being a frequency shift key modulated signal comprising a sequence of signal parts (215, 225), each signal part being modulated at a first or second frequency in accordance with the data, the signal parts modulated at the first frequency having first pulses in first periods (T0) and the signal parts modulated at the second frequency having second pulses in second periods (T1). Energy of the visible light corresponding to a pulse in a respective period has center of gravity in time.

Abstract: A circuit comprising a controller (2) for controlling a pulse width modulated input signal, and a driver (4) configured to supply current to a load (6) based on the input signal, wherein over the on time of each pulse width modulation period the driver (4) supplies current to the load (6) with a second frequency that is greater than the first frequency. The controller (2) is configured to control the duty cycle to set the output of the load (6) to a desired output level, and to dither the duty cycle about a point corresponding to the desired output level.

Abstract: A coded light component is modulated into emitted light on one of multiple channels each having a different modulation frequency. Modulation in the light causes a receiving camera to experience an apparent temporal frequency due to sequential capture of multiple frames and an apparent spatial frequency due to sequential exposure of spatial portions within each frame. Each channel can be detected by a detection module of the camera based on a respective combination of values of the apparent temporal and spatial frequency corresponding to the respective modulation frequency. The detection module has a respective response on each channel that varies as a function of the apparent temporal frequency. The channel for modulating the coded light component is selected from amongst a predetermined set having a property that the response of the detection module on each channel will have a minimum substantially at the apparent temporal frequency of each other channel.

Abstract: The invention relates to a system and methods for providing conditional access to indoor location information in a system comprising a mobile device (320), a positioning webservice (310) and an authorization authority (360), the method comprising: the mobile device (320) performing the steps of: transmitting license information to the authorization authority (360) and transmitting a request for indoor location information to the positioning webservice, the request comprising a request-location-estimate corresponding to a location estimate of the mobile device (320) at the time of making the request, the authorization authority (360) performing the steps of: receiving the license information, verifying whether the license information authorizes access to indoor location information by the mobile device (320), issuing a secure proof, verifiable by the positioning webservice (310) upon successful verification, the secure proof indicating that the license information authorizes access to indoor location informati

Abstract: The present invention relates to a mobile device for detecting light. The mobile device (300) includes a photo detector (320) which is arranged at the end of a socket barrel (114) of an audio jack socket in the mobile device. The socket barrel serves to collimate the light onto the photo detector.