Methods and systems for matching keypoints and tracking regions between frames of video data

A processing system for processing video data comprising a plurality of images, the system comprising:

• a processor, the processor being configured to:
• obtain, for each of said plurality of images, a segmentation in a plurality of regions and a set of keypoints, a keypoint in the image comprising a pixel location and an area surrounding the pixel location having an average radius given by its scale which defines its support;
• track at least one region between a first image and a subsequent image of said plurality of images based on an appearance of the at least one region and a region in said subsequent image;
• and
• find a matched region in the subsequent image taking into account a matching between keypoints in the first image and the subsequent image,
• wherein the tracking of two regions, one from the first image and the other from the subsequent image, are matched if the two regions have a number of matching keypoints in common which is non-zero and if overall similarity of the two regions or what the two regions have in common is larger than a predetermined value;
• associate at least one first keypoint to the at least one region in said first image when at least half of its support disk intersects with the at least one region;
• match a subsequent keypoint in said subsequent image with said first keypoint;
• and
• determine a matching of the at least one region with a subsequent region in said subsequent image based on information regarding said matched keypoints.