US 12,249,151 B2
Crowd anomaly detection
Aleksey Lipchin, Newton, MA (US); and Maksim Bolonkin, Waltham, MA (US)
Assigned to MOTOROLA SOLUTIONS, INC., Chicago, IL (US)
Filed by MOTOROLA SOLUTIONS, INC., Chicago, IL (US)
Filed on Nov. 17, 2023, as Appl. No. 18/512,904.
Application 18/512,904 is a continuation in part of application No. 18/325,650, filed on May 30, 2023.
Prior Publication US 2024/0404290 A1, Dec. 5, 2024
Int. Cl. G06V 20/00 (2022.01); G06T 7/20 (2017.01); G06V 10/34 (2022.01); G06V 10/50 (2022.01); G06V 20/40 (2022.01); G06V 20/52 (2022.01); G08B 31/00 (2006.01)
CPC G06V 20/53 (2022.01) [G06T 7/20 (2013.01); G06V 10/34 (2022.01); G06V 10/50 (2022.01); G06V 20/41 (2022.01); G08B 31/00 (2013.01); G06T 2207/30232 (2013.01); G06T 2207/30242 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A method for detecting an anomaly in a region of interest of a camera, the method comprising:
capturing video data using an image sensor; and
detecting an anomaly by:
obtaining the video data captured using the image sensor;
determining a number of people detected within each of a plurality of frames of the video data;
for each moment t, determining an average number of people n1(t) over a time interval (t−Δt1, t), where Δt1 is greater than or equal to the moment t;
for each moment t, determining an average number of people n2(t) over a time interval (t−Δt2, t), where Δt2 is greater than or equal to Δt1;
for each moment t, determining a change Δn in an average number of people based on at least one selected from the group consisting of the average number of people n1(t) and the average number of people n2(t);
for each moment t, selecting one of a plurality of first histograms based on the average number of people n2(t);
for each moment t, determining a probability ρ of the change Δn in the average number of people based on the selected one of the plurality of first histograms;
determining whether the probability ρ is less than a threshold probability ρ*; and
in response to determining that the probability ρ is less than a threshold probability ρ*, generating an alert indicating that an anomalous crowd size change is detected.