Method of counting objects in a monitored environment and apparatus for the same
View Patent ↗Methods and system for determining, a number of objects, without tracking each of the objects, in first and second fields-of-view. First and second video frames are received from first and second image sources. The image sources have the first and second fields-of-view, and the fields-of-view are known to overlap at least in part. The number of objects is determined based on the first and second video frames and the known overlap.
1. A computerized method of video analysis comprising:
a) receiving a plurality of first video frames, the first video frames being generated over a period time by a first image source having a first field of view;
b) receiving a plurality of second video frames, the second video frames being generated over a period of time by a second image source having a second field of view, the second field of view having a known overlap with at least part of the first field-of-view; and
c) sub-dividing the first and second fields-of-view into two or more image regions:
d) classifying each of the image regions in the first field-of-view overlapping with image regions in the second field of view as an overlapping image region, classifying each of the image regions in the second field-of-view overlapping with image regions in the first field of view as an overlapping image region, and classifying the remainder of the image regions as non-overlapping image regions: and
(e) determining a number of objects, without tracking each of the objects, in the first and second fields-of-view wherein the number of objects equals the sum of the number of objects included in each non-overlapping image region and the maximum number of objects among each of the overlapping image regions.
2. The computerized method of video analysis of claim 1 further comprising maintaining a data structure identifying the image regions as either overlapping or non-overlapping.
3. The computerized method of claim 2 further comprising: receiving updated overlap information; and altering data in the data structure identifying image regions that correspond to overlapping or non-overlapping image regions based on the updated overlap information.
4. The computerized method of claim 1 further comprising averaging the number of objects included in the first and second fields-of-view over at least two instants in time.
5. A computerized system for video analysis comprising:
a) a receiving module configured to receive a plurality of first video frames, the first video frames being generated over a period time by a first image source having a first field-of-view and to receive a plurality of second video frames, the second video frames being generated over a period of time by a second image source having a second field-of-view, the second field of view having a known overlap with at least part of the first field-of-view; and
b) a processing module configured to (i) sub-divide the first and second fields-of-view into two or more image regions, (ii) classify each of the image regions in the first field-of-view overlapping with image regions in the second field of view as an overlapping image region, (iii) classify each of the image regions in the second field-of-view overlapping with image regions in the first field of view as an overlapping image region, (iv) classify the remainder of the image regions as non-overlapping image regions: and (v) determine a number of objects, without tracking the objects, wherein the number of objects equals the sum of the number of objects included in each non-overlapping image region and the maximum number of objects among each of the overlapping image regions.
6. The computerized system for video analysis of claim 5 wherein, the processing module is further configured to maintain a data structure identifying the image regions classified as either overlapping or non-overlapping.
7. The computerized system for claim 6 , wherein the processing module is further configured to receive updated overlap information, and to alter data in the data structure overlapping or non-overlapping image regions based on the updated overlap information.
8. The computerized system for claim 5 wherein the processing module is further configured to average the number of objects included in the first and second fields-of-view over at least two instants in time.