Image stabilization techniques for video surveillance systems

摘要

A behavioral recognition system may include both a computer vision engine and a machine learning engine configured to observe and learn patterns of behavior in video data. Certain embodiments may provide image stabilization of a video stream obtained from a camera. An image stabilization module in the behavioral recognition system obtains a reference image from the video stream. The image stabilization module identifies alignment regions within the reference image based on the regions of the image that are dense with features. Upon determining that the tracked features of a current image is out of alignment with the reference image, the image stabilization module uses the most feature dense alignment region to estimate an affine transformation matrix to apply to the entire current image to warp the image into proper alignment.

主权项

1. A method for stabilizing camera images captured by a video recording device and evaluated by a video analytics application, the method comprising:
identifying candidate regions within a reference frame to use in aligning a stream of frames captured by a video camera, wherein the candidate regions are sorted in descending order by a density of tracked features within each candidate region; designating a candidate region having a highest density of tracked features among the candidate regions as an alignment region for each captured frame; and upon determining that the stream is unstable based on the tracked features in a current frame being misaligned relative to the corresponding features of the reference frame:
determining an affine transformation matrix for the current frame based on the alignment region,warping the current frame using the affine transformation matrix such that the features in the alignment region of the current frame match the corresponding features of the reference frame,identifying a registration error between the warped current frame and the reference frame, andupon determining that the registration error is within a tolerance threshold, designating the warped current frame as a stabilized frame.