Abstract: Examples relate to a method, an apparatus and a computer program for determining distance information based on Time of Flight (ToF) sensor data. The method includes obtaining the ToF sensor data, determining one or more saturated regions within the ToF sensor data, determining distance information for one or more boundary regions located adjacent to the one or more saturated regions based on the ToF sensor data, and determining distance information for at least a part of the one or more saturated regions based on the distance information of the one or more boundary regions.

Abstract: Provided is a method for compensating light reflections from a cover of a time-of-flight camera in an image of a scene that is sensed by the time-of-flight camera. The method includes receiving the image of the scene from the time-of-flight camera. Further, the method includes modifying the image of the scene using a reference image to obtain a compensated image of the scene. Pixels of the reference image indicate reference values exclusively related to light reflections from the cover of the time-of-flight camera. Additionally, the method includes outputting the compensated image.

Abstract: A method for compensating stray light caused by an object in a scene that is sensed by a time-of-flight camera is provided. The method includes receiving an image of the scene from the time-of-flight camera. Further, the method includes controlling the time-of-flight camera to capture a reference image of the scene using a code modulated signal for illumination such that a measurement range of the time-of-flight camera is limited to a distance range around the object. The method additionally includes modifying the image of the scene or an image derived therefrom using the reference image to obtain a compensated image of the scene. The method includes outputting the compensated image.

Abstract: Techniques for simultaneous time-of-flight (ToF) measurement and information signal transmission. An information signal is superimposed on a series of light pulses by emitting the series of light pulses in groups of N regularly-spaced pulses and selectively varying time intervals between successive groups of pulses, such that the resulting varying time intervals between successive groups of emitted pulses are indicative of values of the information signal. Pixels configured to demodulate received light using a pulsed reference signal derived from the modulating signal are controlled to generate pixel signal values, each being indicative of a time-of-flight from the ToF measurement device to an object and back. This controlling comprises varying time intervals between successive groups of reference signal pulses in the same way time intervals between the emitted pulses are varied, so that the superimposition of the information signal has no effect on the ToF measurements.

Abstract: Distance ambiguities arising from indirect time-of-flight (ToF) measurements are resolved by using additional information from two or more coded-modulation measurements. An indirect ToF measurement is performed for a pixel of an image processor, to obtain a value indicative of an apparent distance to an imaged object or scene. First and second coded-modulation measurements are also performed, using respective combination of modulation code and reference signals, such that correlation peaks corresponding to these measurements overlap and cover respective first and second adjoining ranges of distances to imaged objects. First and second mask values are determined from the correlation values obtained from the coded-modulation measurements and are used to determine whether the value indicating the apparent distance indicates an actual distance within the first range of distances or within the second range of distances.

Abstract: Examples relate to a method for determining distance information of an object using a Time of Flight (ToF) system and to a ToF system. The method includes emitting modulated light towards the object using a light source. The method includes measuring a reflection of the modulated light using a ToF sensor module. The reflection of the modulated light is generated by successive reflections of the modulated light by the object and by an additional reflective surface. The method includes determining the distance information of the object based on the measured reflection of the modulated light.

Abstract: An example method for performing depth measurements with an image sensor comprises, for at least a first pixel, performing one or more continuous-wave phase measurements for the first pixel and performing a coded-modulation measurement for the first pixel. The method further comprises determining a mask value for the first pixel, based on the coded-modulation measurement, and applying the mask value to a distance value calculated from the one or more continuous-wave phase measurements, to obtain a masked distance value for the first pixel that has no ambiguity due to phase wrapping.

Abstract: A method for determining relative motion between a time-of-flight camera and an object in a scene sensed by the time-of-flight camera is provided. The method includes receiving at least two sets of raw images of the scene from the time-of-flight camera, each set including at least one raw image. The raw images are based on correlations of a modulated reference signal and measurement signals of the time-of-flight camera. The measurement signals are based on a modulated light signal emitted by the object. The method includes determining, for each set of raw images, a value indicating a respective phase difference between the modulated light and reference signals based on the respective set of raw images, and determining information about relative motion between the time-of-flight camera and object based on the values indicating the phase differences. The method includes outputting the information about relative motion between the time-of-flight camera and the object.

Abstract: Examples relate to a method, an apparatus and a computer program for detecting a presence of airborne particles. A reference measurement of an environment of a depth image sensor module is obtained. The reference measurement is based on a measurement of modulated light in a first time interval. The modulated light is reflected by features of the environment of the depth image sensor module. A subsequent measurement of modulated light is obtained in a second time interval. The presence of the airborne particles is detected based on the subsequent measurement of the modulated light, by using the reference measurement performed in the first time interval to disregard all or part of the features of the environment of the depth image sensor module. A signal indicative of one or more properties of the detected airborne particles is generated based on the detected presence of the airborne particles.

Abstract: A time of flight imaging apparatus includes a plurality of sensor pixels configured to receive an external light signal modulated with an external modulation frequency. The time of flight imaging apparatus further includes pixel circuitry configured to generate a sensor pixels output signal based on the external light signal and a reference signal having a reference frequency. The sensor pixels output signal has a frequency depending on a difference between the external modulation frequency and the reference frequency. The time of flight imaging apparatus further includes synchronization circuitry configured to adjust the reference frequency of the reference signal based on the sensor pixels output signal.

Abstract: A method for determining relative motion between a time-of-flight camera and an object in a scene sensed by the time-of-flight camera is provided. The method includes receiving at least two sets of raw images of the scene from the time-of-flight camera, each set including at least one raw image. The raw images are based on correlations of a modulated reference signal and measurement signals of the time-of-flight camera. The measurement signals are based on a modulated light signal emitted by the object. The method includes determining, for each set of raw images, a value indicating a respective phase difference between the modulated light and reference signals based on the respective set of raw images, and determining information about relative motion between the time-of-flight camera and object based on the values indicating the phase differences. The method includes outputting the information about relative motion between the time-of-flight camera and the object.

Abstract: Examples relate to a method for determining distance information of an object using a Time of Flight (ToF) system and to a ToF system. The method includes emitting modulated light towards the object using a light source. The method includes measuring a reflection of the modulated light using a ToF sensor module. The reflection of the modulated light is generated by successive reflections of the modulated light by the object and by an additional reflective surface. The method includes determining the distance information of the object based on the measured reflection of the modulated light.

Abstract: A method for compensating stray light caused by an object in a scene that is sensed by a time-of-flight camera is provided. The method includes receiving an image of the scene from the time-of-flight camera. Further, the method includes controlling the time-of-flight camera to capture a reference image of the scene using a code modulated signal for illumination such that a measurement range of the time-of-flight camera is limited to a distance range around the object. The method additionally includes modifying the image of the scene or an image derived therefrom using the reference image to obtain a compensated image of the scene. The method includes outputting the compensated image.

Abstract: Provided is a method for compensating light reflections from a cover of a time-of-flight camera in an image of a scene that is sensed by the time-of-flight camera. The method includes receiving the image of the scene from the time-of-flight camera. Further, the method includes modifying the image of the scene using a reference image to obtain a compensated image of the scene. Pixels of the reference image indicate reference values exclusively related to light reflections from the cover of the time-of-flight camera. Additionally, the method includes outputting the compensated image.

Abstract: Distance ambiguities arising from indirect time-of-flight (ToF) measurements are resolved by using additional information from two or more coded-modulation measurements. An indirect ToF measurement is performed for a pixel of an image processor, to obtain a value indicative of an apparent distance to an imaged object or scene. First and second coded-modulation measurements are also performed, using respective combination of modulation code and reference signals, such that correlation peaks corresponding to these measurements overlap and cover respective first and second adjoining ranges of distances to imaged objects. First and second mask values are determined from the correlation values obtained from the coded-modulation measurements and are used to determine whether the value indicating the apparent distance indicates an actual distance within the first range of distances or within the second range of distances.

Abstract: Techniques for simultaneous time-of-flight (ToF) measurement and information signal transmission. An information signal is superimposed on a series of light pulses by emitting the series of light pulses in groups of N regularly-spaced pulses and selectively varying time intervals between successive groups of pulses, such that the resulting varying time intervals between successive groups of emitted pulses are indicative of values of the information signal. Pixels configured to demodulate received light using a pulsed reference signal derived from the modulating signal are controlled to generate pixel signal values, each being indicative of a time-of-flight from the ToF measurement device to an object and back. This controlling comprises varying time intervals between successive groups of reference signal pulses in the same way time intervals between the emitted pulses are varied, so that the superimposition of the information signal has no effect on the ToF measurements.

Abstract: Examples relate to a method, an apparatus and a computer program for detecting a presence of airborne particles. A reference measurement of an environment of a depth image sensor module is obtained. The reference measurement is based on a measurement of modulated light in a first time interval. The modulated light is reflected by features of the environment of the depth image sensor module. A subsequent measurement of modulated light is obtained in a second time interval. The presence of the airborne particles is detected based on the subsequent measurement of the modulated light, by using the reference measurement performed in the first time interval to disregard all or part of the features of the environment of the depth image sensor module. A signal indicative of one or more properties of the detected airborne particles is generated based on the detected presence of the airborne particles.

Abstract: Examples relate to a method, an apparatus and a computer program for determining distance information based on Time of Flight (ToF) sensor data. The method includes obtaining the ToF sensor data, determining one or more saturated regions within the ToF sensor data, determining distance information for one or more boundary regions located adjacent to the one or more saturated regions based on the ToF sensor data, and determining distance information for at least a part of the one or more saturated regions based on the distance information of the one or more boundary regions.

Abstract: An example method for performing depth measurements with an image sensor comprises, for at least a first pixel, performing one or more continuous-wave phase measurements for the first pixel and performing a coded-modulation measurement for the first pixel. The method further comprises determining a mask value for the first pixel, based on the coded-modulation measurement, and applying the mask value to a distance value calculated from the one or more continuous-wave phase measurements, to obtain a masked distance value for the first pixel that has no ambiguity due to phase wrapping.

Abstract: A time of flight imaging apparatus includes a plurality of sensor pixels configured to receive an external light signal modulated with an external modulation frequency. The time of flight imaging apparatus further includes pixel circuitry configured to generate a sensor pixels output signal based on the external light signal and a reference signal having a reference frequency. The sensor pixels output signal has a frequency depending on a difference between the external modulation frequency and the reference frequency. The time of flight imaging apparatus further includes synchronization circuitry configured to adjust the reference frequency of the reference signal based on the sensor pixels output signal.