Reduction of background clutter in structured lighting systems

A method for segmenting light from a pulsed illumination source, from background light, in images of a scene obtained by a structured lighting system, the method comprising:

• illuminating the scene with pulses of light from the pulsed illumination source, the pulses of light from the illumination source comprising a first wavelength, and the pulses of light from the illumination source being polarized in a first orientation;
• receiving by an imaging device comprising a polarization filter,
• a first image of the scene comprising a first spectral band, the first spectral band including the first wavelength,
• a second image of the scene comprising a second spectral band, the second spectral band not including the first wavelength,
• a third image of the scene comprising a third spectral band, the third spectral band not including the first wavelength,
• each of the first, second and third images comprising light intensity values for corresponding locations within the scene and, wherein the polarizing filter has a second orientation, the second orientation being substantially aligned to the first orientation;
• calculating, using a computer processor, estimated light intensity values due to background light, for one or more locations as viewed in the first image, by interpolation of the light intensity values for the corresponding locations as viewed in the second and third images;
• and
• subtracting, using the computer processor, the estimated light intensity values due to background light from the light intensity values for the one or more locations as viewed in the first image.

A structured lighting system for segmenting light provided to a scene from background light in images of the scene, the system comprising:

• an illumination source for providing light comprising a first wavelength, to the scene;
• a receiver comprising an imaging device, the receiver operatively arranged to receive,
• a first image of the scene comprising a first spectral band, the first spectral band including the first wavelength,
• a second image of the scene comprising a second spectral band, the second spectral band not including the first wavelength,
• a third image of the scene comprising a third spectral band, the third spectral band not including the first wavelength, and
• each of the first, second and third images comprising light intensity values for corresponding locations within the scene;
• a processor connected to the illuminator and the receiver, the processor operatively arranged to calculate estimated light intensity values due to background light for one or more locations in the first image, by interpolation of the light intensity values for the corresponding locations as viewed in the second and third images and, the processor operatively arranged to subtract the estimated light intensity values due to background light from the light intensity values for the one or more locations as viewed in the first image.