Imager for constructing color and depth images

Abstract

A dual-mode includes a light source configured to project a structured illumination from which visible light can be filtered. The dual-mode imager also includes a detector configured to capture both the structured illumination and visible light from the scene. A temporal or spatial filter is used to selectively block visible light from one or more portions of the detector while passing the structured illumination to the one or more portions of the detector.

1 - 20 . (canceled) 
     
     
         21 . A dual-mode imager for imaging a scene illuminated by visible light, the dual-mode imager comprising:
 a light source configured to project onto the scene a depth-imaging illumination including infrared radiation;   a detector configured to capture both the depth-imaging illumination and the visible light from the scene; and   a filter, between the scene and the detector, to selectively block the visible light from one or more portions of the detector while passing the infrared radiation of the depth-imaging illumination to the one or more portions of the detector.   
     
     
         22 . The dual-mode imager of  claim 21 , where the filter includes a temporal filter configured to temporally alternate between blocking the visible light from the detector and passing the visible light to the detector. 
     
     
         23 . The dual-mode imager of  claim 22 , where the filter includes a rotating wheel filter including one or more portions configured to block the visible light and one or more portions configured to pass the visible light. 
     
     
         24 . The dual-mode imager of  claim 23 , where the rotating wheel filter is configured to block the visible light for approximately half of a rotation and pass the visible light for approximately half of the rotation. 
     
     
         25 . The dual-mode imager of  claim 22 , further comprising a controller to coordinate the temporal filter and the detector such that images captured by the detector while the temporal filter is blocking the visible light from the detector are sorted to construct a depth image, and such that images captured by the detector while the temporal filter is passing the visible light to the detector are sorted to construct a color image. 
     
     
         26 . The dual-mode imager of  claim 25 , where the temporal filter includes a polarizer and a photoelastic modulator to temporally alternate between blocking the visible light from the detector and passing the visible light to the detector without moving parts. 
     
     
         27 . The dual-mode imager of  claim 21 , where the filter includes a spatial filter configured to block the visible light from some portions of the detector while allowing the visible light to pass to other portions of the detector. 
     
     
         28 . The dual-mode imager of  claim 27 , where the detector includes a plurality of spatially alternating pixel groups, and where the spatial filter is configured to block the visible light from every other pixel group of the plurality of spatially alternating pixel groups. 
     
     
         29 . The dual-mode imager of  claim 28 , where the plurality of spatially alternating pixel groups are spatially alternating rows of pixels. 
     
     
         30 . The dual-mode imager of  claim 27 , where the spatial filter includes a polarizer, a wavelength sensitive color rotator, and a patterned polarizer having a polarization orientation that is space variant. 
     
     
         31 . The dual-mode imager of  claim 21 , where the detector includes a complementary metal-oxide-semiconductor. 
     
     
         32 . The dual-mode imager of  claim 21 , where the light source includes a laser having a near-infrared lasing wavelength. 
     
     
         33 . The dual-mode imager of  claim 32 , where the light source includes a disperser configured to disperse a collimated beam from the laser among a range of projection angles to illuminate the scene with a plurality of spaced-apart light features having a near-infrared wavelength. 
     
     
         34 . The dual-mode imager of  claim 21 , further comprising a depth analyzer configured to construct a depth image based on one or more images of the depth-imaging illumination captured by the detector. 
     
     
         35 . The dual-mode imager of  claim 21 , where the depth-imaging illumination is a structured illumination. 
     
     
         36 . A dual-mode imager for imaging a scene, the dual-mode imager comprising:
 a near-infrared light source configured to project onto the scene a depth-imaging illumination having a near-infrared wavelength;   a complementary metal-oxide-semiconductor configured to capture near-infrared light and visible light from the scene; and   a filter optically intermediate the scene and the complementary metal-oxide-semiconductor, the filter including a first portion configured to block a full spectrum of visible light and pass near-infrared light and a second portion configured to pass visible light.   
     
     
         37 . The dual-mode imager of  claim 36 , further comprising a depth analyzer configured to construct a depth image based on one or more images captured by the complementary metal-oxide-semiconductor while the first portion is blocking the full spectrum of visible light from the complementary metal-oxide-semiconductor. 
     
     
         38 . The dual-mode imager of  claim 36 , where the second portion is configured to block near-infrared light. 
     
     
         39 . A method of constructing a color image and a depth image, the method comprising:
 projecting onto a scene a depth-imaging illumination having a near-infrared wavelength;   temporally alternating between blocking from a detector visible light from the scene and passing to the detector the visible light from the scene;   while blocking the visible light from the scene, capturing the depth-imaging illumination with the detector;   while passing the visible light from the scene, capturing the visible light with the detector;   generating the depth image based on the depth-imaging illumination captured with the detector; and   generating the color image based on the visible light captured with the detector.   
     
     
         40 . The method of  claim 39 , where the depth-imaging illumination is a structured illumination.