IMAGE DETECTION AND PROCESSING FOR BUILDING CONTROL

• US 20150279051A1
• Filed: 06/10/2015
• Published: 10/01/2015
• Est. Priority Date: 09/12/2012
• Status: Active Grant

• Current Assignee: Building Robotics, Inc. (Siemens AG)
• Original Assignee: Enlighted, Inc. (Siemens AG)
• Inventors: Kovesi, Peter Dominic, Petridis, Evan Danny, Mohan, Tanuj
• Granted Patent: US 9,367,925 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/20224 Image subtraction
• CPC Class Codes: G06T 2207/30196 Human being; Person
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 7/246 using feature-based methods, e.g. the tracking of corners or segments
• CPC Class Codes: G06T 7/254 involving subtraction of images
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: H04N 23/80 Camera processing pipelines; Components thereof

Abstract

Occupancy detection for building environmental control is disclosed. One apparatus includes at least one image sensor and a controller, wherein the controller is operative to obtain a plurality of images from the image sensor, determine a color difference image of a color difference between consecutive images, determine areas of the color difference image wherein the color difference is greater than a threshold, calculate a total change area as an aggregate area of the determined areas, create a list of occupancy candidates based on filtering of the determined areas if the total change area is less than a light change threshold, wherein each occupancy candidate is represented by a connected component, track the one or more occupancy candidates over a period of time, and detect occupancy if one or more of the occupancy candidates is detected to have moved more than a movement threshold over the period of time.

Claims

1. An apparatus, comprising:

at least one image sensor;

a controller, wherein at least one of the controller, or an external controller electronically connected to the controller are operative to;

obtain a plurality of images from the image sensor;

determine a color difference image of a color difference between consecutive images;

determine areas of the color difference image wherein the color difference is greater than a threshold;

calculate a total change area as an aggregate area of the determined areas;

create a list of occupancy candidates based on filtering of the determined areas if the total change area is less than a light change threshold, wherein each occupancy candidate is represented by a connected component;

track the one or more occupancy candidates over a period of time; and

detect occupancy if one or more of the occupancy candidates is detected to have moved more than a movement threshold over the period of time.

2. The apparatus of claim 1, wherein the apparatus is further operative to power an infrared (IR) illuminator proximate the at least one sensor if lighting proximate to the apparatus is sensed to be below a lighting threshold.

3. The apparatus of claim 2, wherein the controller is further operative reduce a frame or image rate of the plurality of images.

5. The apparatus of claim 1, wherein the controller is further operative to measure temporal sequences of movement of the occupancy candidates, and comparing the measured temporal sequences to a database of temporal sequences known to be associated with humans, allowing an estimate of a likelihood that one or more humans appear in the plurality of images.

4. The apparatus of claim 4, wherein the IR illuminator is strobed with a pattern that is synchronous with a frame capture times sequence of the plurality of images.

6. A method of detecting occupancy, comprising:

obtaining a plurality of images;

determining a color difference image of a color difference between consecutive images;

determining areas of the color difference image wherein the color difference is greater than a threshold;

calculating a total change area as an aggregate area of the determined areas;

creating a list of occupancy candidates based on filtering of the determined areas if the total change area is less than a light change threshold, wherein each occupancy candidate is represented by a connected component;

tracking the one or more occupancy candidates over a period of time; and

detecting occupancy if one or more of the occupancy candidates is detected to have moved more than a movement threshold over the period of time.

7. The method of claim 6, further comprising powering an infrared (IR) illuminator proximate to a device that is obtaining a plurality of images if lighting proximate to the device is sensed to be below a lighting threshold.

8. The method of claim 7, further comprising reducing a frame or image rate of the plurality of images.

9. The method of claim 8, wherein the IR illuminator is strobed with a pattern that is synchronous with a frame capture times sequence of the plurality of images.

10. The method of claim 6, further comprising measuring temporal sequences of movement of the occupancy candidates, and comparing the measured temporal sequences to a database of temporal sequences known to be associated with humans, allowing an estimate of a likelihood that one or more humans appear in the plurality of images.