Remote Depth Sensing via Relayed Depth from Diffusion

Patent metadata

Field	Value
Publication number	US-2016330360-A1
Application number	US-201514704726-A
Country	US
Kind code	A1
Filing date	May 5, 2015
Priority date	May 5, 2015
Publication date	Nov 10, 2016
Grant date	—

Abstract

Remote depth sensing techniques are described via relayed depth from diffusion. In one or more implementations, a remote depth sensing system is configured to sense depth as relayed from diffusion. The system includes an image capture system including an image sensor and an imaging lens configured to transmit light to the image sensor through an intermediate image plane that is disposed between the imaging lens and the image sensor, the intermediate plane having an optical diffuser disposed proximal thereto that is configured to diffuse the transmitted light. The system also includes a depth sensing module configured to receive one or more images from the image sensor and determine a distance to one or more objects in an object scene captured by the one or more images using a depth by diffusion technique that is based at least in part on an amount of blurring exhibited by respective said objects in the one or more images.

First claim

What is claimed is:

1 . A remote depth sensing system configured to sense depth as relayed from diffusion, the system comprising:
an image capture system including an image sensor and an imaging lens configured to transmit light to the image sensor through an intermediate image plane that is disposed between the imaging lens and the image sensor, the intermediate plane having an optical diffuser disposed proximal thereto that is configured to diffuse the transmitted light; and a depth sensing module configured to receive one or more images from the image sensor and determine a distance to one or more objects in an object scene captured by the one or more images using a depth by diffusion technique that is based at least in part on an amount of blurring exhibited by respective said objects in the one or more images.

2 . A system as described in claim 1 , wherein the optical diffuser is configured to mechanically switch polarization states to diffuse the transmitted light.

3 . A system as described in claim 1 , wherein the optical diffuser is configured to electrically switch polarization states to diffuse the transmitted light.

4 . A system as described in claim 1 , wherein the image capture system includes a linear polarizer and the optical diffuser is a polarization-sensitive diffuser.

5 . A system as described in claim 4 , wherein the polarization-sensitive diffuser includes a laminate structure having an embedded surface relief laminated with an adjacent liquid crystal layer that is aligned to provide diffusion in a polarization state and does not provide the diffusion for an orthogonal polarization state.

6 . A system as described in claim 5 , wherein an optical path difference (OPD) is minimized by the laminate structure between the polarization state and the orthogonal polarization state.

7 . A system as described in claim 1 , wherein the image sensor is configured to capture a plurality of polarization states simultaneously from the optical diffuser.

8 . A system as described in claim 1 , wherein the optical diffuser is configured to have a random surface relief, alternating optical angular spreaders, an axicon array, prismatic array, diffraction grating, or micro lens array, such that the optical diffuser provides an exit numerical aperture in at least one angular dimension.

9 . A system as described in claim 1 , wherein the image capture system includes a structured light illuminator, an output of which is usable by the depth sensing module as captured by the one or more images to determine the distance to the one or more objects in the object scene.

10 . A system as described in claim 1 , wherein the transmitted light is not visible to a human eye.

11 . A method of remote depth sensing of objects in an image scene using diffusion by a computing device, the method comprising:
receiving one or more images by the computing device of an image scene from an image capture system having diffusion applied internally by the image capture system; determining a distance to one or more objects in the image scene by the computing device based on an amount of blurring exhibited by the one or more objects in the received images; and outputting the determined distance by the computing device.

12 . A method as described in claim 0 , further comprising controlling the application of the diffusion by the computing device.

13 . A method as described in claim 12 , wherein the controlling is performed mechanically to switch polarization states to diffuse light transmitted internally within the image capture system.

14 . A method as described in claim 12 , wherein the controlling is performed electrically to switch polarization states to diffuse light transmitted internally within the image capture system.

15 . An image capture system comprising:
an imaging lens configured to transmit light from an object scene; an image sensor configured to capture the transmitted light from the object scene to form one or more images; and an optical diffuser disposed within an intermediate image plane between the imaging lens and the image sensor, the optical diffuser increasing a depth of field available to the image sensor from the imaging lens.

16 . An image capture system as described in claim 0 , further comprising a depth sensing module configured to receive one or more images from the image sensor and determine a distance to one or more objects in an object scene captured by the one or more images a using depth by diffusion technique that is based at least in part on an amount of blurring exhibited by respective said objects in the one or more images.

17 . An image capture system as described in claim 0 , wherein the application of the diffusion by the optical diffuser is switchable between diffused and non-diffused states.

18 . An image capture system as described in claim 17 , wherein the switching is performed mechanically to switch polarization states to diffuse light transmitted internally within the image capture system.

19 . An image capture system as described in claim 17 , wherein the switching is performed electrically to switch polarization states to diffuse light transmitted internally within the image capture system.

20 . An image capture system as described in claim 0 , wherein the optical diffuser is configured to have a random surface relief, alternating optical angular spreaders, an axicon array, prismatic array, diffraction grating, or micro lens array such that the optical diffuser provides an exit numerical aperture in at least one angular dimension.

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Powell Karlton D
• Pradeep Vivek

Classifications

• H04N13/236

  using varifocal lenses or mirrors · CPC title

• G01B11/24

  for measuring contours or curvatures · CPC title

• H04N13/204

  using stereoscopic image cameras (stereoscopic photography G03B35/00) · CPC title

• H04N13/271

  wherein the generated image signals comprise depth maps or disparity maps · CPC title

• G06T7/571

  from focus · CPC title