SYSTEM AND METHOD FOR COUNTING OBJECTS ON MULTIPLE ROADS USING A PAN, TILT, AND ZOOM CAMERA

1 . A method, comprising:

receiving a plurality of video frames from a camera;

detecting a plurality of objects in the plurality of video frames;

determining, by a computer processing device, a plurality of trajectories, each of the plurality of trajectories corresponding to a single one of the plurality of objects, respectively;

identifying, by the computer processing device, a first thoroughfare from a first subset of the plurality of trajectories; and

determining, by the computer processing device, a first number of the plurality of objects that cross a first flow cut line on the first thoroughfare.

2 . The method of claim 1 , wherein the first subset of the plurality of trajectories has a first corresponding directionality, the method further comprising:

identifying a second thoroughfare from a second plurality of trajectories, wherein the second plurality of trajectories has a second corresponding directionality that is different than the first corresponding directionality; and

determining a second number of the plurality of objects that cross a second flow cut line on the second thoroughfare.

3 . The method of claim 1 , wherein detecting the plurality of objects comprises performing blob detection on the plurality of video frames.

4 . The method of claim 3 , further comprising removing a subset of the plurality of objects based on at least one of: a blob area threshold, a blob density threshold, a blob aspect ratio threshold, or a blob orientation threshold, wherein a remaining subset of the plurality of objects comprises vehicles or pedestrians.

5 . The method of claim 1 , wherein detecting the plurality of objects comprises:

dividing each of the plurality of video frames into regions of interest; and

performing object detection by a first detector on each of the regions of interest.

6 . The method of claim 5 , further comprising:

determining that no objects were detected in a subset of the regions of interest; and

performing object detection by a second detector on only the subset of the regions of interest.

7 . The method of claim 6 , wherein at least one of the first detector and the second detector comprises intelligent microservices of a publish-subscribe system.

8 . The method of claim 1 , wherein the camera is a pan, tilt, and zoom camera, further comprising:

determining a coverage metric for the pan, tilt, and zoom camera; and

modifying a camera angle of the pan, tilt, and zoom camera based on the coverage metric.

9 . The method of claim 1 , further comprising calculating a centroid, a slope, and a length of the flow cut line, wherein the first flow cut line is perpendicular to the first subset of trajectories.

10 . The method of claim 1 , further comprising:

determining that the first flow cut line is within a threshold of an edge of the plurality of video frames; and

modifying a camera zoom of the camera based on the determining.

11 . The method of claim 1 , further comprising:

receiving a new video frame from the camera;

detecting a new object in the new video frame; and

matching the new object to the first subset of the plurality of trajectories.

12 . A publish-subscribe system, comprising:

a computer processing device to:

receive a plurality of video frames from a camera;

detect a plurality of objects in the plurality of video frames;

determine a plurality of trajectories, each of the plurality of trajectories corresponding to a single one of the plurality of objects, respectively;

identify a first thoroughfare from a first subset of the plurality of trajectories; and

determine a first number of the plurality of objects that cross a first flow cut line on the first thoroughfare.

13 . The system of claim 12 , wherein to detect the plurality of objects the processing device is further to perform blob detection on the plurality of video frames.

14 . The system of claim 13 , the processing device further to remove a subset of the plurality of objects based on at least one of: a blob area threshold, a blob density threshold, a blob aspect ratio threshold, or a blob orientation threshold, wherein a remaining subset of the plurality of objects comprises vehicles or pedestrians.

15 . The system of claim 12 , wherein to detect the plurality of objects the processing device is further to:

divide each of the plurality of video frames into regions of interest; and

perform object detection by a first detector on each of the regions of interest.

16 . The system of claim 15 , the processing device further to:

determine that no objects were detected in a subset of the regions of interest; and

perform object detection by a second detector on only the subset of the regions of interest.

17 . The system of claim 12 , wherein the camera is a pan, tilt, and zoom camera, the processing device further to:

determine a coverage metric for the pan, tilt, and zoom camera; and

modify a camera angle of the pan, tilt, and zoom camera based on the coverage metric.

18 . The system of claim 12 , the processing device further to:

receive a new video frame from the camera;

detect a new object in the new video frame; and

match the new object to the first subset of the plurality of trajectories.

19 . A non-transitory computer-readable storage medium including instructions that, when executed by a computer processing device, cause the computer processing device to:

receive a plurality of video frames from a camera;

detect a plurality of objects in the plurality of video frames;

determine, by the computer processing device, a plurality of trajectories, each of the plurality of trajectories corresponding to a single one of the plurality of objects, respectively;

identify, by the computer processing device, a first thoroughfare from a first subset of the plurality of trajectories; and

determine, by the computer processing device, a first number of the plurality of objects that cross a first flow cut line on the first thoroughfare.

20 . The non-transitory computer-readable storage medium of claim 19 , wherein to detect the plurality of objects the processing device is further to:

divide each of the plurality of video frames into regions of interest;

perform object detection by a first detector on each of the regions of interest;

determine that no objects were detected in a subset of the regions of interest; and

perform object detection by a second detector on only the subset of the regions of interest.