Patent ID: 11972622
Assignee: AXIS AB
Field: Computer technology (Electrical engineering)
Classification: CPC G | IPC G

Claim 0:
1. A method for updating a coordinate of an annotated point in a digital image due to unintentional camera movement, the method being performed by an image processing device, the method comprising:
obtaining a current digital image of a scene, the current digital image having been captured by a stationary mounted camera subsequent to unintentional movement of the camera relative the scene, wherein the current digital image is associated with at least one annotated point, and wherein each at least one annotated point has a respective coordinate in the current digital image, wherein there are at least two annotated points, and wherein the at least two annotated points define a border of any of: a privacy mask in the current digital image, a virtual trip wire in the scene, a surveillance zone in the scene;
identifying an amount of the unintentional movement by comparing position indicative information in the current digital image to position indicative information in a previous digital image of the scene, the previous digital image having been captured prior to unintentional movement of the camera, wherein the position indicative information in the current digital image is represented by a first set of keypoints extracted from the current digital image, wherein the position indicative information in the previous digital image is represented by a second set of keypoints extracted from the previous digital image, wherein the second set of keypoints is a subset of all keypoints extractable from the previous digital image, wherein the previous digital image is associated with at least one annotated point having a respective coordinate in the previous digital image, and wherein the second set of keypoints is restricted to only include keypoints located within a predefined radius from the coordinate of the at least one annotated point in the previous digital image; and
updating the coordinate of each at least one annotated point in accordance with the identified amount of the unintentional movement and a camera homography.