Direction sensitive motion detector camera

• US 10,417,882 B2
• Filed: 10/24/2017
• Issued: 09/17/2019
• Est. Priority Date: 10/24/2017
• Status: Active Grant

• Current Assignee: The Chamberlain Group LLC
• Original Assignee: The Chamberlain Group, Inc. (The Chamberlain Group LLC)
• Inventors: Bretschneider, Eric C., Fitzgibbon, James J.
• Primary Examiner(s): Lam, Hung H
• Application Number:
  US15/792,329
• Publication Number:
  US 20190122513A1
• Time in Patent Office: 693 Days
• CPC Class Codes: G01B 11/026 by measuring distance between sensor and object G01B11/0608 takes precedence
• CPC Class Codes: G01B 11/14 for measuring distance or clearance between spaced objects or spaced apertures G01B11/26 takes precedence; rangefinders G01C3/00
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/20076 Probabilistic image processing
• CPC Class Codes: G06T 2207/30232 Surveillance
• CPC Class Codes: G06T 7/215 Motion-based segmentation
• CPC Class Codes: G06T 7/254 involving subtraction of images
• CPC Class Codes: G06T 7/60 Analysis of geometric attributes
• CPC Class Codes: G08B 13/19608 Tracking movement of a target, e.g. by detecting an object predefined as a target, using target direction and or velocity to predict its new position
• CPC Class Codes: H04N 23/54 Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
• CPC Class Codes: H04N 23/67 Focus control based on electronic image sensor signals

Abstract

A motion detector camera is configured to differentiate between an object or objects passing through the field of view of the camera and an object or objects approaching the sensor. In one example, motion is detected with a camera configured to identify and selectively filter specific directions of motion. The motion detector compares pixel changes, corresponding to the basic area or size of the object, from frame to frame, and detects the amount of increase in change or decrease in change. An increasing change in the area or size of an object indicates that an object is approaching, and a decreasing change in the area or size of an object indicates that an object that is receding.

Claims

1. An apparatus for detecting direction of movement, the apparatus comprising:

a camera;

a processing circuit in communication with the camera and configured to;

receive data from the camera representing an image captured in a frame by the camera;

detect a first size for an object in a field of view for a first frame captured by the camera;

detect a second size for the object in the field of view for a second frame captured by the camera, the second frame being captured later in time than the first frame;

compare the first size to the second size for the object;

determine, based upon the comparison, that the second size is larger than the first size by more than a first threshold; and

in response to the second size being larger than the first size by more than the first threshold, automatically effect execution of a first action by a device in communication with the camera,

wherein the processing circuit is configured to detect the first size for the object in the field of view for the first frame by;

determining an average pixel brightness for at least two frames captured by the camera;

comparing the average pixel brightness to a pixel brightness value for individual pixels in the field of view of the first frame; and

defining the object as a set of pixels in the field of view of the first frame having a brightness value different from the average pixel brightness by a brightness threshold.

2. The apparatus of claim 1 wherein the processing circuit is further configured to detect the first size for the object in the field of view for the first frame by defining the first size of the object as a first frame total number of pixels in the field of view of the first frame having a brightness value different from the average pixel brightness by the brightness threshold.

3. The apparatus of claim 2 wherein the processing circuit is configured to compare the first size for the object to the second size for the object by comparing the first frame total number of pixels in the field of view of the first frame to a second frame total number of pixels in the field of view of the second frame having a brightness value different from the average pixel brightness for at least two frames captured by the camera by the brightness threshold.

4. The apparatus of claim 1 wherein the processing circuit is further configured to detect the first size for the object in the field of view for the first frame by defining the first size of the object as one or both of:

a) a maximum or average width of contiguous pixels in the field of view of the first frame having a brightness value different from the average pixel brightness by the brightness threshold;

or b) a maximum or average height of contiguous pixels in the field of view of the first frame having a brightness value different from the average pixel brightness by the brightness threshold.

5. The apparatus of claim 4 wherein the processing circuit is configured to compare the first size for the object to the second size for the object comprises one or both of:

comparing the maximum or average width of contiguous pixels in the field of view of the first frame to a second frame maximum or average width of contiguous pixels in the field of view of the second frame having a brightness value different from an average pixel brightness for at least two frames captured by the camera by the brightness threshold;

comparing the maximum or average height of contiguous pixels in the field of view of the first frame to a second frame maximum or average height of contiguous pixels in the field of view of the second frame having a brightness value different from an average pixel brightness for at least two frames captured by the camera by the brightness threshold.

6. The apparatus of claim 1 wherein the processing circuit is further configured to detect a series of sizes for the object over a series of frames captured by the camera between capturing the first frame and the second frame;

wherein the detecting the series of sizes for the object comprises defining a size of the object in a given frame of the series of frames as a total number of pixels in the field of view of the given frame having a brightness value different from the average pixel brightness by the brightness threshold;

wherein the determining that the second size is larger than the first size by more than the first threshold comprises determining that the sizes of the object are increasing over the series of frames and that a rate of change of the sizes of the object over the series of frames exceeds a rate threshold.

7. The apparatus of claim 1 wherein the processing circuit is further configured to detect a series of sizes for the object over a series of frames captured by the camera between capturing the first frame and the second frame;

wherein the detecting the sizes for the object comprises defining a size of the object in a given frame of the series of frames as a total number of pixels in the field of view of the given frame having a brightness value different from the average pixel brightness by the brightness threshold;

wherein the determining that the second size is larger than the first size by more than the first threshold comprises determining that the sizes of the object are increasing over the series of frames and that a percentage of change of the sizes of the object over the series of frames exceeds a percentage threshold.

15. The apparatus of claim 1 wherein the automatically effecting execution of the first action by the device in communication with the camera further comprises turning on a light that directs illumination into the field of view for the camera.

8. An apparatus for detecting direction of movement, the apparatus comprising:

a camera;

a processing circuit in communication with the camera and configured to;

receive data from the camera representing an image captured in a frame by the camera;

detect a first size for an object in a field of view for a first frame captured by the camera;

detect a second size for the object in the field of view for a second frame captured by the camera, the second frame being captured later in time than the first frame;

compare the first size to the second size for the object;

determine, based upon the comparison, that the second size is larger than the first size by more than a first threshold; and

in response to the second size being larger than the first size by more than the first threshold, automatically effect execution of a first action by a device in communication with the camera,

wherein the processing circuit is configured to detect the first size for the object in the field of view for the first frame by;

comparing pixel brightness for a set of pixels from a prior frame captured by the camera prior to a corresponding set of pixels from the first frame; and

defining the object as a set of pixels in the field of view of the first frame having a brightness value different from the pixel brightness for corresponding pixels from the prior frame by a pixel brightness threshold.

9. The apparatus of claim 8 wherein the processing circuit is configured to detect the first size for the object in the field of view for the first frame by defining the first size of the object as a first frame total number of pixels in the field of view of the first frame having a brightness value different from the pixel brightness for corresponding pixels from the prior frame by the pixel brightness threshold.

10. The apparatus of claim 9 wherein the processing circuit is configured to compare the first size to the second size for the object by comparing the first frame total number of pixels to a second frame total number of pixels in the field of view of the second frame having a pixel brightness value different from pixel brightness for corresponding pixels from a prior frame captured by the camera by a pixel brightness threshold.

11. The apparatus of claim 8 wherein the processing circuit is configured to detect the first size for the object in the field of view for the first frame by defining the first size of the object as one or both of a maximum or average width of contiguous pixels in the field of view of the first frame having a brightness value different from the average pixel brightness by the brightness threshold or a maximum or average height of contiguous pixels in the field of view of the first frame having a brightness value different from the average pixel brightness by the brightness threshold.

12. The apparatus of claim 11 wherein the processing circuit is configured to compare the first size to the second size for the object by one or both of:

comparing the maximum or average width of contiguous pixels in the field of view of the first frame to a second frame maximum or average width of contiguous pixels in the field of view of the second frame having a brightness value different from an average pixel brightness for at least two frames captured by the camera by the brightness threshold;

comparing the maximum or average height of contiguous pixels in the field of view of the first frame to a second frame maximum or average height of contiguous pixels in the field of view of the second frame having a brightness value different from an average pixel brightness for at least two frames captured by the camera by the brightness threshold.

13. The apparatus of claim 8 wherein the processing circuit is further configured to detect that the second size is larger than the first size by more than the first threshold by a series of sizes for the object over a series of frames captured by the camera between capturing the first frame and the second frame;

wherein the detecting the sizes for the object comprises defining a size of the object in a given frame of the series of frames as a frame total number of pixels in the field of view of the given frame having a brightness value different from the pixel brightness for corresponding pixels from the prior frame by the pixel brightness threshold;

wherein the determining that the second size is larger than the first size by more than the first threshold comprises determining that the sizes of the object are increasing over the series of frames and that a rate of change of the sizes of the object over the series of frames exceeds a rate threshold.

14. The apparatus of claim 8 wherein the processing circuit is further configured to detect a series of sizes for the object over a series of frames captured by the camera between capturing the first frame and the second frame;

wherein the detecting the sizes for the object comprises defining a size of the object in a given frame of the series of frames as a frame total number of pixels in the field of view of the given frame having a brightness value different from the pixel brightness for corresponding pixels from the prior frame by the pixel brightness threshold;

wherein the determining that the second size is larger than the first size by more than the first threshold comprises determining that the sizes of the object are increasing over the series of frames and that a percentage of change of the sizes of the object over the series of frames exceeds a percentage threshold.

18. The apparatus of claim 8 wherein the automatically effecting execution of the first action by the device in communication with the camera further comprises turning on a light that directs illumination into the field of view for the camera.

16. An apparatus for detecting direction of movement, the apparatus comprising:

a camera;

a processing circuit in communication with the camera and configured to;

capture a first frame, a second frame, and a third frame at different times by the camera;

compare pixel brightness for a set of pixels from the first frame to a corresponding set of pixels from the second frame to eliminate a background and to define a first pixel set having a brightness difference greater than a pixel brightness threshold;

compare pixel brightness for a set of pixels from the second frame to a corresponding set of pixels from the third frame to eliminate a background and to define a third pixel set having a brightness difference greater than a pixel brightness threshold;

compare the size of the first pixel set to the size of the second pixel set;

determine that the size of the second pixel set is larger than the size of the first pixel set by more than a first threshold;

in response to the size of the second pixel set being larger than the size of the first pixel set by more than the first threshold, automatically effect execution of a first action by a device in communication with the camera.

17. The apparatus of claim 16 wherein the processor circuit is further configured to automatically effect execution of the first action by turning on a light that directs light into the field of view for the camera.