A novel correspondence-less approach is proposed to find a thin plate spline map between a pair of deformable 3D objects represented by triangular surface meshes. The proposed method works without landmark extraction and feature correspondences. The aligning transformation is found simply by solving a system of nonlinear equations. Each equation is generated by integrating a nonlinear function over the object's domains. We derive recursive formulas for the efficient computation of these integrals. Based on a series of comparative tests on a large synthetic dataset, our triangular mesh-based algorithm outperforms state of the art methods both in terms of computing time and accuracy. The applicability of the proposed approach has been demonstrated on the registration of 3D lung CT volumes. © 2013 IEEE.

%B IEEE Conference on Computer Vision and Pattern Recognition (CVPR) %I IEEE %C Portland, OR, USA %P 2275 - 2282 %8 June 2013 %G eng %9 Conference paper %R 10.1109/CVPR.2013.295 %0 Book Section %B Proceedings of International Conference on Digital Image Computing: Techniques and Applications (DICTA) %D 2013 %T Elastic Registration of 3D Deformable Objects %A Zsolt Santa %A Zoltan Kato %E Geoff West %E Péter Kövesi %XA novel correspondence-less approach is proposed to find a non-linear aligning transformation between a pair of deformable 3D objects. Herein, we consider a polynomial deformation model, but our framework can be easily adapted to other common deformations. The basic idea of the proposed method is to set up a system of nonlinear equations whose solution directly provides the parameters of the aligning transformation. Each equation is generated by integrating a nonlinear function over the object's domains. Thus the number of equations is determined by the number of adopted nonlinear functions yielding a flexible mechanism to generate sufficiently many equations. While classical approaches would establish correspondences between the shapes, our method works without landmarks. The efficiency of the proposed approach has been demonstrated on a large synthetic dataset as well as in the context of medical image registration.

%B Proceedings of International Conference on Digital Image Computing: Techniques and Applications (DICTA) %I IEEE %C New York %P 1 - 7 %8 Nov 2013 %G eng %U http://www.inf.u-szeged.hu/~kato/papers/dicta2012.pdf %9 Conference paper %R 10.1109/DICTA.2012.6411674 %0 Book Section %B International Conference on Digital Image Computing: Techniques and Applications (DICTA) %D 2013 %T Pose Estimation of Ad-hoc Mobile Camera Networks %A Zsolt Santa %A Zoltan Kato %E Paulo de Souza %E Ulrich Engelke %E Ashfaqur Rahman %XAn algorithm is proposed for the pose estimation of ad-hoc mobile camera networks with overlapping views. The main challenge is to estimate camera parameters with respect to the 3D scene without any specific calibration pattern, hence allowing for a consistent, camera-independent world coordinate system. The only assumption about the scene is that it contains a planar surface patch of a low-rank texture, which is visible in at least two cameras. Such low-rank patterns are quite common in urban environments. The proposed algorithm consists of three main steps: relative pose estimation of the cameras within the network, followed by the localization of the network within the 3D scene using a low-rank surface patch, and finally the estimation of a consistent scale for the whole system. The algorithm follows a distributed architecture, hence the computing power of the participating mobile devices are efficiently used. The performance and robustness of the proposed algorithm have been analyzed on both synthetic and real data. Experimental results confirmed the relevance and applicability of the method.

%B International Conference on Digital Image Computing: Techniques and Applications (DICTA) %I IEEE %C Hobart, TAS %P 88 - 95 %8 2013 %G eng %9 Conference paper %M 14000303 %R 10.1109/DICTA.2013.6691514 %0 Conference Paper %B IEEE International Conference on Cognitive Infocommunications (CogInfoCom) %D 2012 %T A Unifying Framework for Non-linear Registration of 3D Objects %A Zsolt Santa %A Zoltan Kato %X

An extension of our earlier work is proposed to find a non-linear aligning transformation between a pair of deformable 3D objects. The basic idea is to set up a system of nonlinear equations whose solution directly provides the parameters of the aligning transformation. Each equation is generated by integrating a nonlinear function over the object's domains. Thus the number of equations is determined by the number of adopted nonlinear functions yielding a flexible mechanism to generate sufficiently many equations. While classical approaches would establish correspondences between the shapes, our method works without landmarks. Experiments with 3D polynomial and thin plate spline deformations confirm the performance of the framework.

%B IEEE International Conference on Cognitive Infocommunications (CogInfoCom) %I IEEE %C Kosice, Slovakia %P 547 - 552 %8 Dec 2012 %@ 978-1-4673-5187-4 %G eng %U http://www.inf.u-szeged.hu/~kato/papers/coginfocomm2012.pdf %9 Conference paper %R 10.1109/CogInfoCom.2012.6422041