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2011


Thumb xl jampani11 spie
Role of expertise and contralateral symmetry in the diagnosis of pneumoconiosis: an experimental study

Jampani, V., Vaidya, V., Sivaswamy, J., Tourani, K. L.

In Proc. SPIE 7966, Medical Imaging: Image Perception, Observer Performance, and Technology Assessment, 2011, Florida, March 2011 (inproceedings)

Abstract
Pneumoconiosis, a lung disease caused by the inhalation of dust, is mainly diagnosed using chest radiographs. The effects of using contralateral symmetric (CS) information present in chest radiographs in the diagnosis of pneumoconiosis are studied using an eye tracking experimental study. The role of expertise and the influence of CS information on the performance of readers with different expertise level are also of interest. Experimental subjects ranging from novices & medical students to staff radiologists were presented with 17 double and 16 single lung images, and were asked to give profusion ratings for each lung zone. Eye movements and the time for their diagnosis were also recorded. Kruskal-Wallis test (χ2(6) = 13.38, p = .038), showed that the observer error (average sum of absolute differences) in double lung images differed significantly across the different expertise categories when considering all the participants. Wilcoxon-signed rank test indicated that the observer error was significantly higher for single-lung images (Z = 3.13, p < .001) than for the double-lung images for all the participants. Mann-Whitney test (U = 28, p = .038) showed that the differential error between single and double lung images is significantly higher in doctors [staff & residents] than in non-doctors [others]. Thus, Expertise & CS information plays a significant role in the diagnosis of pneumoconiosis. CS information helps in diagnosing pneumoconiosis by reducing the general tendency of giving less profusion ratings. Training and experience appear to play important roles in learning to use the CS information present in the chest radiographs.

url link (url) [BibTex]

2011

url link (url) [BibTex]


Thumb xl problem
Recovering Intrinsic Images with a Global Sparsity Prior on Reflectance

Gehler, P., Rother, C., Kiefel, M., Zhang, L., Schölkopf, B.

In Advances in Neural Information Processing Systems 24, pages: 765-773, (Editors: Shawe-Taylor, John and Zemel, Richard S. and Bartlett, Peter L. and Pereira, Fernando C. N. and Weinberger, Kilian Q.), Curran Associates, Inc., Red Hook, NY, USA, 2011 (inproceedings)

Abstract
We address the challenging task of decoupling material properties from lighting properties given a single image. In the last two decades virtually all works have concentrated on exploiting edge information to address this problem. We take a different route by introducing a new prior on reflectance, that models reflectance values as being drawn from a sparse set of basis colors. This results in a Random Field model with global, latent variables (basis colors) and pixel-accurate output reflectance values. We show that without edge information high-quality results can be achieved, that are on par with methods exploiting this source of information. Finally, we are able to improve on state-of-the-art results by integrating edge information into our model. We believe that our new approach is an excellent starting point for future developments in this field.

website + code pdf poster Project Page Project Page [BibTex]

website + code pdf poster Project Page Project Page [BibTex]


Thumb xl openbiosafetylab  a virtual world based biosafety training application for medical students
OpenBioSafetyLab: A virtual world based biosafety training application for medical students

Nakasone, A., Tang, S., Shigematsu, M., Heinecke, B., Fujimoto, S., Prendinger, H.

In International Conference on Information Technology: New Generations (ITNG), IEEE CPS, 2011 (inproceedings)

PDF [BibTex]

PDF [BibTex]


Thumb xl fosterembs2011
Combining wireless neural recording and video capture for the analysis of natural gait

Foster, J., Freifeld, O., Nuyujukian, P., Ryu, S., Black, M. J., Shenoy, K.

In Proc. 5th Int. IEEE EMBS Conf. on Neural Engineering, pages: 613-616, IEEE, 2011 (inproceedings)

pdf Project Page [BibTex]

pdf Project Page [BibTex]


Thumb xl segmentation isbi11
Tagged Cardiac MR Image Segmentation Using Boundary & Regional-Support and Graph-based Deformable Priors

Xiang, B., Wang, C., Deux, J., Rahmouni, A., Paragios, N.

In IEEE International Symposium on Biomedical Imaging (ISBI), 2011 (inproceedings)

pdf [BibTex]

pdf [BibTex]


Thumb xl multi nrsfm
Multiview Structure from Motion in Trajectory Space

Zaheer, A., Akhter, I., Mohammad, H. B., Marzban, S., Khan, S.

In Computer Vision (ICCV), 2011 IEEE International Conference on, pages: 2447-2453, 2011 (inproceedings)

Abstract
Most nonrigid objects exhibit temporal regularities in their deformations. Recently it was proposed that these regularities can be parameterized by assuming that the non- rigid structure lies in a small dimensional trajectory space. In this paper, we propose a factorization approach for 3D reconstruction from multiple static cameras under the com- pact trajectory subspace representation. Proposed factor- ization is analogous to rank-3 factorization of rigid struc- ture from motion problem, in transformed space. The benefit of our approach is that the 3D trajectory basis can be directly learned from the image observations. This also allows us to impute missing observations and denoise tracking errors without explicit estimation of the 3D structure. In contrast to standard triangulation based methods which require points to be visible in at least two cameras, our ap- proach can reconstruct points, which remain occluded even in all the cameras for quite a long time. This makes our solution especially suitable for occlusion handling in motion capture systems. We demonstrate robustness of our method on challenging real and synthetic scenarios.

pdf project page [BibTex]

pdf project page [BibTex]


Thumb xl 1000dayimagesmall
Neural control of cursor trajectory and click by a human with tetraplegia 1000 days after implant of an intracortical microelectrode array

(J. Neural Engineering Highlights of 2011 Collection. JNE top 10 cited papers of 2010-2011.)

Simeral, J. D., Kim, S., Black, M. J., Donoghue, J. P., Hochberg, L. R.

J. of Neural Engineering, 8(2):025027, 2011 (article)

Abstract
The ongoing pilot clinical trial of the BrainGate neural interface system aims in part to assess the feasibility of using neural activity obtained from a small-scale, chronically implanted, intracortical microelectrode array to provide control signals for a neural prosthesis system. Critical questions include how long implanted microelectrodes will record useful neural signals, how reliably those signals can be acquired and decoded, and how effectively they can be used to control various assistive technologies such as computers and robotic assistive devices, or to enable functional electrical stimulation of paralyzed muscles. Here we examined these questions by assessing neural cursor control and BrainGate system characteristics on five consecutive days 1000 days after implant of a 4 × 4 mm array of 100 microelectrodes in the motor cortex of a human with longstanding tetraplegia subsequent to a brainstem stroke. On each of five prospectively-selected days we performed time-amplitude sorting of neuronal spiking activity, trained a population-based Kalman velocity decoding filter combined with a linear discriminant click state classifier, and then assessed closed-loop point-and-click cursor control. The participant performed both an eight-target center-out task and a random target Fitts metric task which was adapted from a human-computer interaction ISO standard used to quantify performance of computer input devices. The neural interface system was further characterized by daily measurement of electrode impedances, unit waveforms and local field potentials. Across the five days, spiking signals were obtained from 41 of 96 electrodes and were successfully decoded to provide neural cursor point-and-click control with a mean task performance of 91.3% ± 0.1% (mean ± s.d.) correct target acquisition. Results across five consecutive days demonstrate that a neural interface system based on an intracortical microelectrode array can provide repeatable, accurate point-and-click control of a computer interface to an individual with tetraplegia 1000 days after implantation of this sensor.

pdf pdf from publisher link (url) Project Page [BibTex]


Thumb xl scia2011
Unscented Kalman Filtering for Articulated Human Tracking

Anders Boesen Lindbo Larsen, Soren Hauberg, Kim S. Pedersen

In Image Analysis, 6688, pages: 228-237, Lecture Notes in Computer Science, (Editors: Heyden, Anders and Kahl, Fredrik), Springer Berlin Heidelberg, 2011 (inproceedings)

Publishers site PDF [BibTex]

Publishers site PDF [BibTex]


no image
Adaptation for perception of the human body: Investigations of transfer across viewpoint and pose

Sekunova, A., Black, M. J., Parkinson, L., Barton, J. S.

Vision Sciences Society, 2011 (conference)

[BibTex]

[BibTex]


Thumb xl icip1
Level Set Segmentation with Robust Image Gradient Energy and Statistical Shape Prior

Si Yong Yeo, Xianghua Xie, Igor Sazonov, Perumal Nithiarasu

In IEEE International Conference on Image Processing, pages: 3397 - 3400, 2011 (inproceedings)

Abstract
We propose a new level set segmentation method with statistical shape prior using a variational approach. The image energy is derived from a robust image gradient feature. This gives the active contour a global representation of the geometric configuration, making it more robust to image noise, weak edges and initial configurations. Statistical shape information is incorporated using nonparametric shape density distribution, which allows the model to handle relatively large shape variations. Comparative examples using both synthetic and real images show the robustness and efficiency of the proposed method.

link (url) [BibTex]

link (url) [BibTex]


Thumb xl cmbve1
Variational Level Set Segmentation Using Shape Prior

Si Yong Yeo, Xianghua Xie, Igor Sazonov, Perumal Nithiarasu

In International Conference on Mathematical and Computational Biomedical Engineering, 2011 (inproceedings)

[BibTex]

[BibTex]


Thumb xl andriluka2011
Benchmark datasets for pose estimation and tracking

Andriluka, M., Sigal, L., Black, M. J.

In Visual Analysis of Humans: Looking at People, pages: 253-274, (Editors: Moesland and Hilton and Kr"uger and Sigal), Springer-Verlag, London, 2011 (incollection)

publisher's site Project Page [BibTex]

publisher's site Project Page [BibTex]


Thumb xl foe2011
Fields of experts

Roth, S., Black, M. J.

In Markov Random Fields for Vision and Image Processing, pages: 297-310, (Editors: Blake, A. and Kohli, P. and Rother, C.), MIT Press, 2011 (incollection)

Abstract
Fields of Experts are high-order Markov random field (MRF) models with potential functions that extend over large pixel neighborhoods. The clique potentials are modeled as a Product of Experts using nonlinear functions of many linear filter responses. In contrast to previous MRF approaches, all parameters, including the linear filters themselves, are learned from training data. A Field of Experts (FoE) provides a generic, expressive image prior that can capture the statistics of natural scenes, and can be used for a variety of machine vision tasks. The capabilities of FoEs are demonstrated with two example applications, image denoising and image inpainting, which are implemented using a simple, approximate inference scheme. While the FoE model is trained on a generic image database and is not tuned toward a specific application, the results compete with specialized techniques.

publisher site [BibTex]

publisher site [BibTex]


Thumb xl hmdb snapshot1
HMDB: A Large Video Database for Human Motion Recognition

Kuhne, H., Jhuang, H., Garrote, E., Poggio, T., Serre, T.

In IEEE International Conference on Computer Vision (ICCV), 2011 (inproceedings)

code, webpage, dataset pdf [BibTex]

code, webpage, dataset pdf [BibTex]


Thumb xl screen shot 2012 03 13 at 2.41.46 pm
Dorsal Stream: From Algorithm to Neuroscience

Jhuang, H.

PhD Thesis, MIT, 2011 (techreport)

pdf [BibTex]


no image
Context dependent changes in grip selectivity in primate ventral premotor cortex

Franquemont, L., Vargas-Irwin, C., Black, M., Donoghue, J.

2011 Abstract Viewer and Itinerary Planner, Online, Society for Neuroscience, 2011, Online (conference)

[BibTex]

[BibTex]


no image
Towards a freely moving animal model: Combining markerless multi-camera video capture and wirelessly transmitted neural recording for the analysis of walking

Foster, J., Freifeld, O., Nuyujukian, P., Ryu, S., Black, M., Shenoy, K.

2011 Abstract Viewer and Itinerary Planner, Society for Neuroscience, 2011, Online (conference)

Project Page [BibTex]

Project Page [BibTex]


Thumb xl ijnmbe1
Modelling pipeline for subject-specific arterial blood flow—A review

Igor Sazonov, Si Yong Yeo, Rhodri Bevan, Xianghua Xie, Raoul van Loon, Perumal Nithiarasu

International Journal for Numerical Methods in Biomedical Engineering, 27(12):1868–1910, 2011 (article)

Abstract
In this paper, a robust and semi-automatic modelling pipeline for blood flow through subject-specific arterial geometries is presented. The framework developed consists of image segmentation, domain discretization (meshing) and fluid dynamics. All the three subtopics of the pipeline are explained using an example of flow through a severely stenosed human carotid artery. In the Introduction, the state-of-the-art of both image segmentation and meshing is presented in some detail, and wherever possible the advantages and disadvantages of the existing methods are analysed. Followed by this, the deformable model used for image segmentation is presented. This model is based upon a geometrical potential force (GPF), which is a function of the image. Both the GPF calculation and level set determination are explained. Following the image segmentation method, a semi-automatic meshing method used in the present study is explained in full detail. All the relevant techniques required to generate a valid domain discretization are presented. These techniques include generating a valid surface mesh, skeletonization, mesh cropping, boundary layer mesh construction and various mesh cosmetic methods that are essential for generating a high-quality domain discretization. After presenting the mesh generation procedure, how to generate flow boundary conditions for both the inlets and outlets of a geometry is explained in detail. This is followed by a brief note on the flow solver, before studying the blood flow through the carotid artery with a severe stenosis.

[BibTex]

[BibTex]


Thumb xl tnip1
Geometrically Induced Force Interaction for Three-Dimensional Deformable Models

Si Yong Yeo, Xianghua Xie, Igor Sazonov, Perumal Nithiarasu

IEEE Transactions on Image Processing, 20(5):1373 - 1387, 2011 (article)

Abstract
In this paper, we propose a novel 3-D deformable model that is based upon a geometrically induced external force field which can be conveniently generalized to arbitrary dimensions. This external force field is based upon hypothesized interactions between the relative geometries of the deformable model and the object boundary characterized by image gradient. The evolution of the deformable model is solved using the level set method so that topological changes are handled automatically. The relative geometrical configurations between the deformable model and the object boundaries contribute to a dynamic vector force field that changes accordingly as the deformable model evolves. The geometrically induced dynamic interaction force has been shown to greatly improve the deformable model performance in acquiring complex geometries and highly concave boundaries, and it gives the deformable model a high invariancy in initialization configurations. The voxel interactions across the whole image domain provide a global view of the object boundary representation, giving the external force a long attraction range. The bidirectionality of the external force field allows the new deformable model to deal with arbitrary cross-boundary initializations, and facilitates the handling of weak edges and broken boundaries. In addition, we show that by enhancing the geometrical interaction field with a nonlocal edge-preserving algorithm, the new deformable model can effectively overcome image noise. We provide a comparative study on the segmentation of various geometries with different topologies from both synthetic and real images, and show that the proposed method achieves significant improvements against existing image gradient techniques.

[BibTex]

[BibTex]


Thumb xl dagm2011imagesmall
Shape and pose-invariant correspondences using probabilistic geodesic surface embedding

Tsoli, A., Black, M. J.

In 33rd Annual Symposium of the German Association for Pattern Recognition (DAGM), 6835, pages: 256-265, Lecture Notes in Computer Science, (Editors: Mester, Rudolf and Felsberg, Michael), Springer, 2011 (inproceedings)

Abstract
Correspondence between non-rigid deformable 3D objects provides a foundation for object matching and retrieval, recognition, and 3D alignment. Establishing 3D correspondence is challenging when there are non-rigid deformations or articulations between instances of a class. We present a method for automatically finding such correspondences that deals with significant variations in pose, shape and resolution between pairs of objects.We represent objects as triangular meshes and consider normalized geodesic distances as representing their intrinsic characteristics. Geodesic distances are invariant to pose variations and nearly invariant to shape variations when properly normalized. The proposed method registers two objects by optimizing a joint probabilistic model over a subset of vertex pairs between the objects. The model enforces preservation of geodesic distances between corresponding vertex pairs and inference is performed using loopy belief propagation in a hierarchical scheme. Additionally our method prefers solutions in which local shape information is consistent at matching vertices. We quantitatively evaluate our method and show that is is more accurate than a state of the art method.

pdf talk Project Page [BibTex]

pdf talk Project Page [BibTex]


Thumb xl srf2011 2
Steerable random fields for image restoration and inpainting

Roth, S., Black, M. J.

In Markov Random Fields for Vision and Image Processing, pages: 377-387, (Editors: Blake, A. and Kohli, P. and Rother, C.), MIT Press, 2011 (incollection)

Abstract
This chapter introduces the concept of a Steerable Random Field (SRF). In contrast to traditional Markov random field (MRF) models in low-level vision, the random field potentials of a SRF are defined in terms of filter responses that are steered to the local image structure. This steering uses the structure tensor to obtain derivative responses that are either aligned with, or orthogonal to, the predominant local image structure. Analysis of the statistics of these steered filter responses in natural images leads to the model proposed here. Clique potentials are defined over steered filter responses using a Gaussian scale mixture model and are learned from training data. The SRF model connects random fields with anisotropic regularization and provides a statistical motivation for the latter. Steering the random field to the local image structure improves image denoising and inpainting performance compared with traditional pairwise MRFs.

publisher site [BibTex]

publisher site [BibTex]


Thumb xl thesis
Spatial Models of Human Motion

Soren Hauberg

University of Copenhagen, 2011 (phdthesis)

PDF [BibTex]

PDF [BibTex]


no image
Visual orientation and direction selectivity through thalamic synchrony

Kelly, S., Stanley, G., Jin, J., Wang, Y., Desbordes, G., Wang, Q., Black, M., Alonso, J.

2011 Abstract Viewer and Itinerary Planner, Society for Neuroscience, 2011, Online (conference)

[BibTex]

[BibTex]


no image
Use of the BrainGate neural inteface system for more than five years by a woman with tetraplegia

Hochberg, L., Bacher, D., Barefoot, L., Berhanu, E., Black, M., Cash, S., Feldman, J., Gallivan, E., Homer, M., Jarosiewicz, B., King, B., Liu, J., Malik, W., Masse, N., Berge, J., Rosler, D., Schmansky, N., Simeral, J., Travers, B., Truccolo, W., Donoghue, J.

2011 Abstract Viewer and Itinerary Planner, Society for Neuroscience, 2011, Onine (conference)

[BibTex]

[BibTex]


no image
Extracting 3D Structures from Biomedical Data

Xianghua Xie, Si Yong Yeo, Igor Sazonov, Perumal Nithiarasu

Proceedings of the 5th International Conference on Bioinformatics and Biomedical Engineering, 2011 (conference)

[BibTex]

[BibTex]


Thumb xl teaser bchap
Model-Based Pose Estimation

Pons-Moll, G., Rosenhahn, B.

In Visual Analysis of Humans: Looking at People, pages: 139-170, 9, (Editors: T. Moeslund, A. Hilton, V. Krueger, L. Sigal), Springer, 2011 (inbook)

book page pdf [BibTex]

book page pdf [BibTex]


Thumb xl illumination cvpr11
Illumination Estimation and Cast Shadow Detection through a Higher-order Graphical Model

Panagopoulos, A., Wang, C., Samaras, D., Paragios, N.

In IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2011 (inproceedings)

pdf [BibTex]

pdf [BibTex]


Thumb xl femursegmentation miccai11
Pose-invariant 3D Proximal Femur Estimation through Bi-Planar Image Segmentation with Hierarchical Higher-Order Graph-based Priors

Wang, C., Boussaid, H., Simon, L., Lazennec, J., Paragios, N.

In International Conference, Medical Image Computing and Computer Assisted Intervention (MICCAI), 2011 (inproceedings)

pdf [BibTex]

pdf [BibTex]


Thumb xl sufacetracking cvpr11
Intrinsic Dense 3D Surface Tracking

Zeng, Y., Wang, C., Wang, Y., Gu, X., Samaras, D., Paragios, N.

In IEEE Conference on Computer Vision and Pattern Recognition (CVPR), 2011 (inproceedings)

pdf [BibTex]

pdf [BibTex]


Thumb xl emmcvpr2012
Data-Driven Importance Distributions for Articulated Tracking

Soren Hauberg, Kim S. Pedersen

In Energy Minimization Methods in Computer Vision and Pattern Recognition, 6819, pages: 287-299, Lecture Notes in Computer Science, (Editors: Boykov, Yuri and Kahl, Fredrik and Lempitsky, Victor and Schmidt, Frank), Springer Berlin Heidelberg, 2011 (inproceedings)

Publishers site Code PDF Suppl. material [BibTex]

Publishers site Code PDF Suppl. material [BibTex]


Thumb xl kdcv2011 teaser
A Physically Natural Metric for Human Motion and the Associated Brownian Motion Model

Soren Hauberg, Kim Steenstrup Pedersen

In 1st IEEE Workshop on Kernels and Distances for Computer Vision (ICCV workshop), 2011 (inproceedings)

Workshop link [BibTex]

Workshop link [BibTex]


Thumb xl thumb system1
Virtual Visual Servoing for Real-Time Robot Pose Estimation

Gratal, X., Romero, J., Kragic, D.

In International Federation of Automatic Control World Congress, IFAC, 2011 (inproceedings)

Pdf [BibTex]

Pdf [BibTex]


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Cooperative Localization Based on Visually Shared Objects

Lima, P., Santos, P., Oliveira, R., Ahmad, A., Santos, J.

In RoboCup 2010: Robot Soccer World Cup XIV, pages: 350-361, Lecture Notes in Computer Science ; 6556, Springer, Berlin, Germany, 2011 (inproceedings)

Abstract
In this paper we describe a cooperative localization algorithm based on a modification of the Monte Carlo Localization algorithm where, when a robot detects it is lost, particles are spread not uniformly in the state space, but rather according to the information on the location of an object whose distance and bearing is measured by the lost robot. The object location is provided by other robots of the same team using explicit (wireless) communication. Results of application of the method to a team of real robots are presented.

DOI [BibTex]

DOI [BibTex]


Thumb xl ijnmbe1
Computational flow studies in a subject-specific human upper airway using a one-equation turbulence model. Influence of the nasal cavity

Prihambodo Saksono, Perumal Nithiarasu, Igor Sazonov, Si Yong Yeo

International Journal for Numerical Methods in Biomedical Engineering, 87(1-5):96–114, 2011 (article)

Abstract
This paper focuses on the impact of including nasal cavity on airflow through a human upper respiratory tract. A computational study is carried out on a realistic geometry, reconstructed from CT scans of a subject. The geometry includes nasal cavity, pharynx, larynx, trachea and two generations of airway bifurcations below trachea. The unstructured mesh generation procedure is discussed in some length due to the complex nature of the nasal cavity structure and poor scan resolution normally available from hospitals. The fluid dynamic studies have been carried out on the geometry with and without the inclusion of the nasal cavity. The characteristic-based split scheme along with the one-equation Spalart–Allmaras turbulence model is used in its explicit form to obtain flow solutions at steady state. Results reveal that the exclusion of nasal cavity significantly influences the resulting solution. In particular, the location of recirculating flow in the trachea is dramatically different when the truncated geometry is used. In addition, we also address the differences in the solution due to imposed, equally distributed and proportionally distributed flow rates at inlets (both nares). The results show that the differences in flow pattern between the two inlet conditions are not confined to the nasal cavity and nasopharyngeal region, but they propagate down to the trachea.

[BibTex]

[BibTex]


Thumb xl sufacematching ssvm11
Discrete Minimum Distortion Correspondence Problems for Non-rigid Shape Matching

Wang, C., Bronstein, M. M., Bronstein, A. M., Paragios, N.

In International Conference on Scale Space and Variational Methods in Computer Vision (SSVM), 2011 (inproceedings)

pdf [BibTex]

pdf [BibTex]


Thumb xl viewpointinvariantmodel iccv11.
Viewpoint Invariant 3D Landmark Model Inference from Monocular 2D Images Using Higher-Order Priors

Wang, C., Zeng, Y., Simon, L., Kakadiaris, I., Samaras, D., Paragios, N.

In IEEE International Conference on Computer Vision (ICCV), 2011 (inproceedings)

pdf [BibTex]

pdf [BibTex]


no image
Correspondence estimation from non-rigid motion information

Wulff, J., Lotz, T., Stehle, T., Aach, T., Chase, J. G.

In Proc. SPIE, Proc. SPIE, (Editors: B. M. Dawant, D. R. Haynor), SPIE, 2011 (inproceedings)

Abstract
The DIET (Digital Image Elasto Tomography) system is a novel approach to screen for breast cancer using only optical imaging information of the surface of a vibrating breast. 3D tracking of skin surface motion without the requirement of external markers is desirable. A novel approach to establish point correspondences using pure skin images is presented here. Instead of the intensity, motion is used as the primary feature, which can be extracted using optical flow algorithms. Taking sequences of multiple frames into account, this motion information alone is accurate and unambiguous enough to allow for a 3D reconstruction of the breast surface. Two approaches, direct and probabilistic, for this correspondence estimation are presented here, suitable for different levels of calibration information accuracy. Reconstructions show that the results obtained using these methods are comparable in accuracy to marker-based methods while considerably increasing resolution. The presented method has high potential in optical tissue deformation and motion sensing.

pdf link (url) DOI [BibTex]

pdf link (url) DOI [BibTex]


Thumb xl ijcv2012
Predicting Articulated Human Motion from Spatial Processes

Soren Hauberg, Kim S. Pedersen

International Journal of Computer Vision, 94, pages: 317-334, Springer Netherlands, 2011 (article)

Publishers site Code Paper site PDF [BibTex]

Publishers site Code Paper site PDF [BibTex]


Thumb xl icann2011
An Empirical Study on the Performance of Spectral Manifold Learning Techniques

Peter Mysling, Soren Hauberg, Kim S. Pedersen

In Artificial Neural Networks and Machine Learning – ICANN 2011, 6791, pages: 347-354, Lecture Notes in Computer Science, (Editors: Honkela, Timo and Duch, Włodzisław and Girolami, Mark and Kaski, Samuel), Springer Berlin Heidelberg, 2011 (inproceedings)

Publishers site PDF [BibTex]

Publishers site PDF [BibTex]


no image
Separation of visual object features and grasp strategy in primate ventral premotor cortex

Vargas-Irwin, C., Franquemont, L., Black, M., Donoghue, J.

Neural Control of Movement, 21st Annual Conference, 2011 (conference)

[BibTex]

[BibTex]

2009


Thumb xl teaser wacv2010
Ball Joints for Marker-less Human Motion Capture

Pons-Moll, G., Rosenhahn, B.

In IEEE Workshop on Applications of Computer Vision (WACV),, December 2009 (inproceedings)

pdf [BibTex]

2009

pdf [BibTex]


no image
Background Subtraction Based on Rank Constraint for Point Trajectories

Ahmad, A., Del Bue, A., Lima, P.

In pages: 1-3, October 2009 (inproceedings)

Abstract
This work deals with a background subtraction algorithm for a fish-eye lens camera having 3 degrees of freedom, 2 in translation and 1 in rotation. The core assumption in this algorithm is that the background is considered to be composed of a dominant static plane in the world frame. The novelty lies in developing a rank-constraint based background subtraction for equidistant projection model, a property of the fish-eye lens. A detail simulation result is presented to support the hypotheses explained in this paper.

link (url) [BibTex]

link (url) [BibTex]


Thumb xl teaser cinc
Parametric Modeling of the Beating Heart with Respiratory Motion Extracted from Magnetic Resonance Images

Pons-Moll, G., Crosas, C., Tadmor, G., MacLeod, R., Rosenhahn, B., Brooks, D.

In IEEE Computers in Cardiology (CINC), September 2009 (inproceedings)

[BibTex]

[BibTex]


Thumb xl ascc09
Computer cursor control by motor cortical signals in humans with tetraplegia

Kim, S., Simeral, J. D., Hochberg, L. R., Donoghue, J. P., Black, M. J.

In 7th Asian Control Conference, ASCC09, pages: 988-993, Hong Kong, China, August 2009 (inproceedings)

pdf [BibTex]

pdf [BibTex]


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ISocRob-MSL 2009 Team Description Paper for Middle Sized League

Lima, P., Santos, J., Estilita, J., Barbosa, M., Ahmad, A., Carreira, J.

13th Annual RoboCup International Symposium 2009, July 2009 (techreport)

Abstract
This paper describes the status of the ISocRob MSL roboticsoccer team as required by the RoboCup 2009 qualification procedures.Since its previous participation in RoboCup, the ISocRob team has car-ried out significant developments in various topics, the most relevantof which are presented here. These include self-localization, 3D objecttracking and cooperative object localization, motion control and rela-tional behaviors. A brief description of the hardware of the ISocRobrobots and of the software architecture adopted by the team is also in-cluded.

[BibTex]

[BibTex]


no image
Denoising Fluorescence Endoscopy: A Motion-Compensated Temporal Recursive Video Filter with an Optimal Minimum Mean Square Error Parametrization

Stehle, T., Wulff, J., Behrens, A., Gross, S., Aach, T.

Abstract
Fluorescence endoscopy is an emerging technique for the detection of bladder cancer. A marker substance is brought into the patient's bladder which accumulates at cancer tissue. If a suitable narrow band light source is used for illumination, a red fluorescence of the marker substance is observable. Because of the low fluorescence photon count and because of the narrow band light source, only a small amount of light is detected by the camera's CCD sensor. This, in turn, leads to strong noise in the recorded video sequence. To overcome this problem, we apply a temporal recursive filter to the video sequence. The derivation of a filter function is presented, which leads to an optimal filter in the minimum mean square error sense. The algorithm is implemented as plug-in for the real-time capable clinical demonstrator platform RealTimeFrame and it is capable to process color videos with a resolution of 768times576 pixels at 50 frames per second.

pdf link (url) DOI [BibTex]


Thumb xl foe2009
Fields of Experts

Roth, S., Black, M. J.

International Journal of Computer Vision (IJCV), 82(2):205-29, April 2009 (article)

Abstract
We develop a framework for learning generic, expressive image priors that capture the statistics of natural scenes and can be used for a variety of machine vision tasks. The approach provides a practical method for learning high-order Markov random field (MRF) models with potential functions that extend over large pixel neighborhoods. These clique potentials are modeled using the Product-of-Experts framework that uses non-linear functions of many linear filter responses. In contrast to previous MRF approaches all parameters, including the linear filters themselves, are learned from training data. We demonstrate the capabilities of this Field-of-Experts model with two example applications, image denoising and image inpainting, which are implemented using a simple, approximate inference scheme. While the model is trained on a generic image database and is not tuned toward a specific application, we obtain results that compete with specialized techniques.

pdf pdf from publisher [BibTex]

pdf pdf from publisher [BibTex]


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Classification of colon polyps in NBI endoscopy using vascularization features

Stehle, T., Auer, R., Gross, S., Behrens, A., Wulff, J., Aach, T., Winograd, R., Trautwein, C., Tischendorf, J.

In Medical Imaging 2009: Computer-Aided Diagnosis, 7260, (Editors: N. Karssemeijer and M. L. Giger), SPIE, February 2009 (inproceedings)

Abstract
The evolution of colon cancer starts with colon polyps. There are two different types of colon polyps, namely hyperplasias and adenomas. Hyperplasias are benign polyps which are known not to evolve into cancer and, therefore, do not need to be removed. By contrast, adenomas have a strong tendency to become malignant. Therefore, they have to be removed immediately via polypectomy. For this reason, a method to differentiate reliably adenomas from hyperplasias during a preventive medical endoscopy of the colon (colonoscopy) is highly desirable. A recent study has shown that it is possible to distinguish both types of polyps visually by means of their vascularization. Adenomas exhibit a large amount of blood vessel capillaries on their surface whereas hyperplasias show only few of them. In this paper, we show the feasibility of computer-based classification of colon polyps using vascularization features. The proposed classification algorithm consists of several steps: For the critical part of vessel segmentation, we implemented and compared two segmentation algorithms. After a skeletonization of the detected blood vessel candidates, we used the results as seed points for the Fast Marching algorithm which is used to segment the whole vessel lumen. Subsequently, features are computed from this segmentation which are then used to classify the polyps. In leave-one-out tests on our polyp database (56 polyps), we achieve a correct classification rate of approximately 90%.

DOI [BibTex]

DOI [BibTex]


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One-shot scanning using de bruijn spaced grids

Ulusoy, A., Calakli, F., Taubin, G.

In Computer Vision Workshops (ICCV Workshops), 2009 IEEE 12th International Conference on, pages: 1786-1792, IEEE, 2009 (inproceedings)

Abstract
In this paper we present a new one-shot method to reconstruct the shape of dynamic 3D objects and scenes based on active illumination. In common with other related prior-art methods, a static grid pattern is projected onto the scene, a video sequence of the illuminated scene is captured, a shape estimate is produced independently for each video frame, and the one-shot property is realized at the expense of space resolution. The main challenge in grid-based one-shot methods is to engineer the pattern and algorithms so that the correspondence between pattern grid points and their images can be established very fast and without uncertainty. We present an efficient one-shot method which exploits simple geometric constraints to solve the correspondence problem. We also introduce De Bruijn spaced grids, a novel grid pattern, and show with strong empirical data that the resulting scheme is much more robust compared to those based on uniform spaced grids.

pdf link (url) DOI [BibTex]

pdf link (url) DOI [BibTex]


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An introduction to Kernel Learning Algorithms

Gehler, P., Schölkopf, B.

In Kernel Methods for Remote Sensing Data Analysis, pages: 25-48, 2, (Editors: Gustavo Camps-Valls and Lorenzo Bruzzone), Wiley, New York, NY, USA, 2009 (inbook)

Abstract
Kernel learning algorithms are currently becoming a standard tool in the area of machine learning and pattern recognition. In this chapter we review the fundamental theory of kernel learning. As the basic building block we introduce the kernel function, which provides an elegant and general way to compare possibly very complex objects. We then review the concept of a reproducing kernel Hilbert space and state the representer theorem. Finally we give an overview of the most prominent algorithms, which are support vector classification and regression, Gaussian Processes and kernel principal analysis. With multiple kernel learning and structured output prediction we also introduce some more recent advancements in the field.

link (url) DOI [BibTex]

link (url) DOI [BibTex]