Monitoring device, tracking method, and non-transitory computer-readable medium

1. A monitoring device comprising:

at least one memory storing instructions, and

at least one processor configured to execute the instructions to;

acquire position information of an object to be tracked, the position information including a first position information acquired at a first timing and second position information acquired at a second timing later than the first timing, the first position information indicating a first position, and the second position information indicating a second position;

estimate a third position of the object to be tracked displayed in an image captured of a predetermined region;

generate path information of the object to be tracked by supplementing, based on the third position of the object to be tracked, a fourth position of the object to be tracked held between the first position indicated and the second position; and

limit a region in which the third position of the object to be tracked is estimated to fall by use of the position information of the object to be tracked if the object to be tracked fails to be displayed in the image for a predetermined period.

2. The monitoring device according to claim 1 , wherein the at least one processor is further configured to execute the instructions to acquire the position information of the object to be tracked included in AIS information received from the object to be tracked provided with an AIS.

3. The monitoring device according to claim 1 , wherein the at least one processor is further configured to execute the instructions to acquire the position information of the object to be tracked periodically by use of a radar.

4. The monitoring device according to claim 1 , wherein the at least one processor is further configured to execute the instructions to correct the third position of the object to be tracked by use of a difference between a position of the object to be tracked indicated by the position information and the third position of the object to be tracked estimated at a timing when the position information has been acquired.

5. The monitoring device according to claim 1 , wherein the at least one processor is further configured to execute the instructions to estimate the third position of the object to be tracked by use of a particle filter.

6. The monitoring device according to claim 1 , wherein the at least one processor is further configured to execute the instructions to estimate the third position of the object to be tracked by converting image coordinates of the object to be tracked to world coordinates.

7. The monitoring device according to claim 1 , wherein the at least one processor is further configured to execute the instructions to cause the path information to be displayed in the image.

8. The monitoring device according to claim 2 , wherein the at least one processor is further configured to execute the instructions to cause the path information to be displayed on an AIS screen generated based on the AIS information.

9. The monitoring device according to claim 3 , wherein the at least one processor is further configured to execute the instructions to cause the path information to be displayed on a radar screen generated based on information acquired by use of the radar.

10. A tracking method to be executed in a monitoring device, the tracking method comprising:

acquiring position information of an object to be tracked, the position information including a first position information acquired at a first timing and second position information acquired at a second timing later than the first timing, the first position information indicating a first position, and the second position information indicating a second position;

estimating a third position of the object to be tracked displayed in an image captured of a predetermined region;

generating path information of the object to be tracked by supplementing, based on the third position of the object to be tracked, a fourth position of the object to be tracked held between the first position; and

limiting a region in which the third position of the object to be tracked is estimated to fall by use of the position information of the object to be tracked if the object to be tracked fails to be displayed in the image for a predetermined period.

11. A non-transitory computer-readable medium storing a program that causes a computer to execute:

acquiring position information of an object to be tracked, the position information including a first position information acquired at a first timing and second position information acquired at a second timing later than the first timing, the first position information indicating a first position, and the second position information indicating a second position;

estimating a third position of the object to be tracked displayed in an image captured of a predetermined region;

generating path information of the object to be tracked by supplementing, based on the third position of the object to be tracked, a fourth position of the object to be tracked held between the first position and the second position; and

limiting a region in which the third position of the object to be tracked is estimated to fall by use of the position information of the object to be tracked if the object to be tracked fails to be displayed in the image for a predetermined period.