Evaluating the intrinsic similarities between non-rigid 3D shapes is of vital importance in content-based shape retrieval. In this paper, we present a novel intrinsic embedding technique, the contour canonical form, to express the isometry-invariant shape representation. The basic idea is to generate an unbent mapping shape for each subpart by aligning the geodesic contours. In details, we first extract the feature points on the non-rigid shape. Then, their canonical mapping positions are calculated, which are globally optimized under geodesic constraints defined on the shape surface. Guided by these positions, an embedding shape is finally obtained by adaptively rotating and translating the geodesic contours around the corresponding feature point. Compared with existing spectral embedding methods, our approach excels on both the preservation of geometric information and the computational efficiency. In the experiment, the contour canonical form is applied in retrieving non-rigid 3D shapes from the McGill articulated benchmark. The appealing results clearly demonstrate a significant performance improvement of our approach over state-of-the-art methods.

In this paper, based on manifold harmonics, we propose a novel framework for 3D shape similarity comparison and partial matching. First, we propose a novel symmetric mean-value representation to robustly construct high-quality manifold harmonic bases on nonuniform-sampling meshes. Then, based on the manifold harmonic bases constructed, a novel shape descriptor is presented to capture both of global and local features of 3D shape. This feature descriptor is isometry-invariant, i.e., invariant to rigid-body transformations and non-rigid bending. After characterizing 3D models with the shape features, we perform 3D retrieval with a up-to-date discriminative kernel. This kernel is a dimension-free approach to quantifying the similarity between two unordered feature-sets, thus especially suitable for our high-dimensional feature data. Experimental results show that our framework can be effectively used for both comprehensive comparison and partial matching among non-rigid 3D shapes.

Successful multi-target tracking requires locating the targets and labeling their identities. For the laser based tracking system, the latter becomes significantly more challenging when the targets frequently interact with each other. This paper presents a novel on-line supervised learning based method for tracking interacting targets with laser scanner. When the targets do not interact with each other, we collect samples and train a classifier for each target. When the targets are in close proximity, we use these classifiers to assist in tracking. Different evaluations demonstrate that this method has a better tracking performance than previous methods when interactions occur, and can maintain correct tracking under various complex tracking situations.