US Patent 11176409 Distance-independent keypoint detection

Described herein is a method for detecting keypoints in three-dimensional images in which a three-dimensional image of a scene captured by a depth sensing imaging system is processed using a distance-independent keypoint filter. Keypoints are derived from the three-dimensional image by determining a mean shift field and using x- and y-components of the mean shift field to derive intersections of 0-isolines thereof. Positive and negative keypoints or nodes are connected to one another, positive to positive and negative to negative, to form a keygraph structure.