Using a Depth Map of a Monitored Scene to Identify Floors, Walls, and Ceilings

A method, comprising:

• at a camera device having a memory configured to store information, a lens assembly arranged to direct light from a scene, a plurality of image sensing elements configured to receive light from the scene via the lens assembly, a plurality of infrared illuminators configured to transmit infrared light, and a processor, coupled to the plurality of image sensing elements and the plurality of infrared illuminators:
• operating the plurality of infrared illuminators and the image sensing element in a first mode whereby infrared light transmitted by the plurality of infrared illuminators and reflected from the scene is used to generate a two-dimensional image of the scene;
• and
• operating the plurality of infrared illuminators and the image sensing element in a second mode, including:
• sequentially activating a plurality of distinct subsets of the illuminators, each subset illuminating a different portion of the scene;
• for each subset of illuminators, measuring an intensity of reflected light from the scene for each pixel of a plurality of pixels, wherein each pixel corresponds to one or more image sensing elements of the plurality of image sensing elements;
• for each pixel:
• generating a light intensity vector based on the measured intensities for the pixel, wherein the light intensity vector has a component corresponding to each subset of illuminators;
• and
• estimating a pixel depth in the scene using the light intensity vector and a lookup table;
• and
• identifying a planar surface in the scene using the estimated pixel depths.

A non-transitory computer-readable storage medium storing one or more programs configured for execution by a camera device having a memory configured to store information, a lens assembly arranged to direct light from a scene, plurality of image sensing elements configured to receive light from the scene via the lens assembly, a plurality of infrared illuminators configured to transmit infrared light, and a processor, coupled to the plurality of image sensing elements and the plurality of infrared illuminators, wherein the one or more programs comprise instructions for:

• operating the plurality of infrared illuminators and the image sensing element in a first mode whereby infrared light transmitted by the plurality of infrared illuminators and reflected from the scene is used to generate a two-dimensional image of the scene;
• and
• operating the plurality of infrared illuminators and the image sensing element in a second mode, including:
• sequentially activating a plurality of distinct subsets of the illuminators, each subset illuminating a different portion of the scene;
• for each subset of illuminators, measuring an intensity of reflected light from the scene for each pixel of a plurality of pixels, wherein each pixel corresponds to one or more image sensing elements of the plurality of image sensing elements;
• for each pixel:
• generating a light intensity vector based on the measured intensities for the pixel, wherein the light intensity vector has a component corresponding to each subset of illuminators;
• and
• estimating a pixel depth in the scene using the light intensity vector and a lookup table;
• and
• identifying a planar surface in the scene using the estimated pixel depths.