Autonomous lock-on target tracking with geospatial-aware PTZ cameras

摘要

An autonomous lock-on target tracking system and method with geospatial-aware PTZ cameras includes a camera imaging a terrain space. The camera acquires images, and first and second images are aligned. A frame-differencing operation produces a resultant image including blobs corresponding to elements in the terrain space. One of the blobs is classified as an object and tracked as a target. The target is tracked by determining the distance between a centroid of the target and a center of a field of view of the camera, and instructing the camera to move through the distance. The distance is continually updated as the camera and the target move.

主权项

1. A video camera surveillance method comprising the steps of:
providing a camera imaging a terrain space in a field of view of the camera, the field of view having a center; acquiring images in a video stream from the camera; forming an image pair of first and second images between two of the images; aligning the first and second images with respect to each other; performing a frame differencing operation on the image pair to form a binary resultant image including blobs corresponding to elements in the terrain space, the frame differencing operation comprising:
determining an overlapping region of the first and second images;determining a high illumination threshold and a low illumination threshold; andfor each pixel in the overlapping region, identifying the respective pixel as a foreground pixel if (1) the respective pixel in the first image deviates from a corresponding pixel in the second image by at least the high illumination threshold, (2) the respective pixel in the first image deviates from pixels adjacent to the corresponding pixel in the second image by at least the high illumination threshold, and (3) the corresponding pixel in the second image deviates from pixels adjacent to the respective pixel in the first image by at least the low illumination threshold; classifying one of the blobs as an object; selecting the object as a target, the target having a centroid; tracking the target by moving the camera toward the centroid by an amount corresponding to the distance between the centroid and the center of the field of view; and continually repeating the tracking step as the target moves in the terrain space.