Image detection and processing for building control

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.

4. The apparatus of claim 2 , wherein the IR illuminator is strobed with a pattern that is synchronous with a frame capture times sequence 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.

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.