Image segmentation and object tracking method and corresponding system
First Claim
Patent Images
1. An object tracking method applied to an image sequence, said method comprising in series the following steps:
- (A) a segmentation step for defining the regions of a first coarse partition P(t-1) of an image I(t-1), said regions corresponding to the objects to be tracked, and, from said coarse partition P(t-1) and on the basis of a spatial homogeneity criterion, a finer partition FP(t-1);
(B) a projection step for defining a projection PFP(t) of said fine partition FP(t-1) into the current image I(t);
(C) a re-labelling step of said projected fine partition PFP(t), for defining the final partition P(t);
wherein said projection step comprises in series the following sub-steps;
(1) a marker projection sub-step, provided for yielding on the basis of motion and spatial information a set of markers for the current image, said marker projection sub-step itself comprising in series the following operations;
(a) based on a motion estimation operation between the images I(t-1) and I(t), a backwards motion compensation operation of the fine partition FP(t-1), yielding a compensated fine partition CFP(t-1) made of so-called compensated markers;
(b) in said compensated fine partition, a component selection operation, provided for selecting, among the possible unconnected components that correspond to a single label of the coarse partition P(t-1) and have the same label, only the components that, for each of these specific labels, satisfy a predetermined spatial criterion;
(2) a partition creation sub-step, by means of a growing process of said set of compensated markers in order to obtain said final partition.
5 Assignments
0 Petitions
Accused Products
Abstract
This relates to a method for image segmentation and video object tracking. While conventional methods rely on the motion homogeneity of the objects to be tracked, the present method is based on a concept of partition projection in which both spatial and motion information are now exploited, and implemented by means of a modified double partition approach, including a re-segmentation of a first partition followed by a projection step of the obtained fine partition into the current frame. Objects presenting non-homogeneous motion, static objects, and parts of an object with homogeneous motion can thus be tracked.
50 Citations
10 Claims
-
1. An object tracking method applied to an image sequence, said method comprising in series the following steps:
-
(A) a segmentation step for defining the regions of a first coarse partition P(t-1) of an image I(t-1), said regions corresponding to the objects to be tracked, and, from said coarse partition P(t-1) and on the basis of a spatial homogeneity criterion, a finer partition FP(t-1); (B) a projection step for defining a projection PFP(t) of said fine partition FP(t-1) into the current image I(t); (C) a re-labelling step of said projected fine partition PFP(t), for defining the final partition P(t);
wherein said projection step comprises in series the following sub-steps;(1) a marker projection sub-step, provided for yielding on the basis of motion and spatial information a set of markers for the current image, said marker projection sub-step itself comprising in series the following operations; (a) based on a motion estimation operation between the images I(t-1) and I(t), a backwards motion compensation operation of the fine partition FP(t-1), yielding a compensated fine partition CFP(t-1) made of so-called compensated markers; (b) in said compensated fine partition, a component selection operation, provided for selecting, among the possible unconnected components that correspond to a single label of the coarse partition P(t-1) and have the same label, only the components that, for each of these specific labels, satisfy a predetermined spatial criterion; (2) a partition creation sub-step, by means of a growing process of said set of compensated markers in order to obtain said final partition. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A system for an object tracking applied to partitions, resulting from a segmentation of images, of an image sequence, each partition P(t-1) determining in corresponding image I(t-1) regions that define the objects to be tracked and leading after a refined segmentation to a finer partition FP(t-1), said system comprising the serial arrangement of a projection stage, for defining a projection PFP(t) of said fine partition FP(t-1) into the current image I(t), and a re-labelling stage, for defining from said projection fine partition PFP(t) the current partition P(t), wherein said projection stage comprises:
-
(a) a motion estimation circuit, for carrying out a motion estimation between the images I(t-1) and I(t); (b) a motion compensation circuit, for defining, on the basis of said motion estimation applied to said fine partition FP(t-1), a compensated fine partition CFP(t-1) made of so-called compensated markers; (c) a component selection circuit, for selecting, among possible unconnected components that correspond to a single label of the partition P(t-1) and have the same label, only the components that, for each of the specific labels satisfying a predetermined spatial criterion; (d) a partition creation device, for finally defining said current partition P(t) by means of a growing process of the compensated markers. - View Dependent Claims (10)
-
Specification