Time-of-flight depth measurement using modulation frequency adjustment
AssigneeSamsung Electronics Co., Ltd.
InventorsGal Bitan, Roy Yam, Gershi Koltun
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Abstract
In a method for time-of-flight (ToF) based measurement, a scene is illuminated using a ToF light source modulated at a first modulation frequency FMOD(1). While the light is modulated using FMOD(1), depths are measured to respective surface points within the scene, where the surface points are represented by a plurality of respective pixels. At least one statistical distribution parameter is computed for the depths. A second modulation frequency FMOD(2) higher than FMOD(1) is determined based on the at least one statistical distribution parameter. The depths are then re-measured using FMOD(2) to achieve a higher depth accuracy.
Claims20
A time-of-flight (ToF) camera comprising:
- an interface configured to receive a first ToF light source modulated at a first modulation frequency and a second ToF light source modulated at a second modulation frequency;
- and
- an image sensor coupled to an image signal processor configured to measure first depths of a region of interest (ROI) based on the first ToF light source and second depths of the ROI based on the second ToF light source,
- wherein the image signal processor is configured to determine the second modulation frequency based on a measuring result of the first depths.
A time-of-flight (ToF) camera comprising:
- an interface configured to receive a first ToF light source modulated at a first modulation frequency and a second ToF light source modulated at a second modulation frequency;
- an illuminator configured to illuminate a scene using the first ToF light source;
- and
- an image signal processor configured to:
- identify a region of interest (ROI) within the scene;
- measure first depths of a region of interest (ROI) based on the first ToF light source and second depths of the ROI based on the second ToF light source;
- and
- determine the second modulation frequency based on at least one statistical distribution parameter for the first depths,
- wherein the second modulation frequency is different from the first modulation frequency.
A time-of-flight (ToF) camera comprising:
- an illuminator operable to illuminate a scene with modulated light;
- an image sensor comprising pixels to capture the modulated light reflected from surface points in the scene and output voltages representing the same;
- and
- an image signal processor coupled to the illuminator and image sensor and configured to:
- measure depths from the image sensor to surface points within the scene with ToF operations using a first modulation frequency FMOD(1) at which the light is modulated;
- compute at least one statistical distribution parameter for the depths;
- determine a second modulation frequency FMOD(2) higher than FMOD(1) based on the statistical distribution parameter;
- re-measure the depths with the light modulated at FMOD(2);
- re-compute the statistical distribution parameter for the depths that were re-measured;
- and
- determine whether to provide the re-measured depths using FMOD(2) as final measured depths.
Dependencies are inferred from the claim text.