Using Infrared Images of a Monitored Scene to Identify Windows

Patent metadata

Field	Value
Publication number	US-2016366347-A1
Application number	US-201514745230-A
Country	US
Kind code	A1
Filing date	Jun 19, 2015
Priority date	Jun 12, 2015
Publication date	Dec 15, 2016
Grant date	—

Abstract

A camera system includes memory, a lens assembly arranged to direct light from a scene onto an image sensing element, an image sensing element configured to receive light from the scene via the lens assembly, at least one infrared illuminator configured to transmit infrared light, and a processor, coupled to the image sensing element and the illuminators. The processor is configured to operate the illuminators and the image sensing element in a first mode whereby infrared light transmitted by the illuminators and reflected from the scene is used to generate a two-dimensional image of the scene. The processor is also configured to operate the illuminators and the image sensing element in a second mode whereby infrared light transmitted by the illuminators and reflected from the scene is used to detect a first region, located within the scene, having a specific material.

First claim

What is claimed is:

1 . A camera system, comprising:
a memory configured to store information; a lens assembly arranged to direct light from a scene onto an image sensing element; an image sensing element configured to receive light from the scene via the lens assembly; at least one infrared illuminator configured to transmit infrared light; and a processor, coupled to the image sensing element and the at least one infrared illuminator and configured to:
operate the at least one infrared illuminator and the image sensing element in a first mode whereby infrared light transmitted by the at least one infrared illuminator and reflected from the scene is used to generate a two-dimensional image of the scene; and
operate the at least one infrared illuminator and the image sensing element in a second mode whereby infrared light transmitted by the at least one infrared illuminator and reflected from the scene is used to detect a first region, located within the scene, having a specific material.

2 . The camera system of claim 1 , wherein the first region is transparent and the first region is determined to be made of glass.

3 . The camera system of claim 1 , wherein the first mode is operated at night.

4 . The camera system of claim 1 , wherein the camera system comprises a plurality of infrared illuminators, and wherein in the first mode all of infrared illuminators are activated to generate the two-dimensional image.

5 . The camera system of claim 1 , wherein the second mode is a specularity detection mode.

6 . The camera system of claim 1 , wherein the camera system comprises a plurality of infrared illuminators, and wherein at least some of the infrared illuminators are activated at different times to identify the first region.

7 . The camera system of claim 6 , wherein a plurality of subsets of the infrared illuminators are activated in sequence, each subset illuminating a different portion of the scene.

8 . The camera system of claim 6 , wherein a plurality of subsets of the infrared illuminators are activated in sequence and each of the subsets of illuminators is configured at a different angle relative to the image sensing element.

9 . The camera system of claim 1 , wherein in the second mode the processor is configured to:
capture a first image of a scene while one or more of the illuminators are activated; capture a second image of the scene is captured while none of the illuminators are activated; construct a light intensity map for the scene by subtracting light intensity values from the second image from corresponding light intensity values in the first image; and storing to the memory the light intensity map.

10 . The camera system of claim 9 , wherein the first and second images are IR images.

11 . The camera system of claim 9 , wherein the processor is further configured to:
transmit the stored light intensity map to a window detection module configured to identify windows in the scene.

12 . The camera system of claim 9 , wherein the light intensity map comprises a plurality of pixels.

13 . The camera system of claim 9 , wherein the processor is further configured to:
use the light intensity map to identify a plurality of pixels whose corresponding intensity values are within a predefined intensity range; and cluster the identified plurality of pixels into one or more regions including the first region.

14 . The camera system of claim 13 , wherein clustering the identified plurality of pixels into one or more regions further comprises using a depth map that is constructed using the image sensor array.

15 . The camera system of claim 13 , wherein clustering the identified plurality of pixels into one or more regions further comprises using an RGB image of the scene captured using the image sensor array.

16 . The camera system of claim 13 , wherein the predefined intensity range comprises all intensity values below a threshold value, and the specific material is glass, the method thereby determining that the first region corresponds to a window in the scene.

17 . The camera system of claim 16 , wherein determining that the first region corresponds to a window comprises determining that the first region is substantially a quadrilateral.

18 . The camera system of claim 1 , wherein the processor is further configured to:
receive a video stream of the scene from the camera system; review the video stream to detect movement in the scene, wherein the first region is excluded from movement detection; and generate a motion alert when there is motion detected at the scene outside of the first region.

19 . A method, comprising:
at a camera system having a memory configured to store information, a lens assembly arranged to direct light from a scene onto an image sensing element, an image sensing element configured to receive light from the scene via the lens assembly, at least one infrared illuminator configured to transmit infrared light, and a processor, coupled to the image sensing element and the at least one infrared illuminator:
operating the at least one infrared illuminator and the image sensing element in a first mode whereby infrared light transmitted by the at least one infrared illuminator and reflected from the scene is used to generate a two-dimensional image of the scene; and
operating the at least one infrared illuminator and the image sensing element in a second mode whereby infrared light transmitted by the at least one infrared illuminator and reflected from the scene is used to detect a first region, located within the scene, having a specific material.

20 . A non-transitory computer readable storage medium storing one or more programs configured for execution by a camera system having a memory configured to store information, a lens assembly arranged to direct light from a scene onto an image sensing element, an image sensing element configured to receive light from the scene via the lens assembly, at least one infrared illuminator configured to transmit infrared light, and a processor, coupled to the image sensing element and the at least one infrared illuminator, wherein the one or more programs comprise instructions for:
operating the at least one infrared illuminator and the image sensing element in a first mode whereby infrared light transmitted by the at least one infrared illuminator and reflected from the scene is used to generate a two-dimensional image of the scene; and operating the at least one infrared illuminator and the image sensing element in a second mode whereby infrared light transmitted by the at least one infrared illuminator and reflected from the scene is used to detect a first region, located within the scene, having a specific material.

Assignees

• Google Inc

Inventors

• Shin Dongeek
• Dixon Michael

Classifications

• G08B13/19602 Primary

  Image analysis to detect motion of the intruder, e.g. by frame subtraction · CPC title

• H04N23/11

  for generating image signals from visible and infrared light wavelengths · CPC title

• H04N23/45

  for generating image signals from two or more image sensors being of different type or operating in different modes, e.g. with a CMOS sensor for moving images in combination with a charge-coupled device [CCD] for still images · CPC title

• H04N23/90

  Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums · CPC title

• H04N23/74

  by influencing the scene brightness using illuminating means · CPC title