Preprints

  1. Gaussian Splashing: Direct Volumetric Rendering Underwater. arXiv, 2025.
    Nir Mualem, Roy Amoyal, Oren Freifeld, and Derya Akkaynak

  2. Diffeomorphic Temporal Alignment Nets for Time-series Joint Alignment and Averaging. arXiv, 2025.
    Ron Shapira Weber and Oren Freifeld

  3. CPU- and GPU-based Distributed Sampling in Dirichlet Process Mixtures for Large-scale Analysis. arXiv, 2022 ("provisionally accepted" to the Journal of Statistical Software, date of publucation: TBA) .
    Or Dinari*, Raz Zamir*, John Fisher III, and Oren Freifeld.
    ("*" indicates both these authors contributed equally)
    [ PDF ] [ Code: Python; Julia; CUDA/C++]

Peer-Reviewed Publications

NeurIPS 2025 FastJAM: a Fast Joint Alignment Model for Images.
Omri Hirsch*, Ron Shapira Weber*, Shira Ifergane, Oren Freifeld
ICCV 2025 Synchronization of Multiple Videos.
Avihai Naaman*, Ron Shapira Weber*, Oren Freifeld
ICML 2025 TimePoint: Accelerated Time Series Alignment via Self-Supervised Keypoint and Descriptor Learning.
Ron Shapira Weber, Shahar Benishay, Shahaf E. Finder, Andrey Lavrinenko, Oren Freifeld
ICML 2025 Improving the Effective Receptive Field of Message-Passing Neural Networks.
Shahaf E. Finder, Ron Shapira Weber, Moshe Eliasof, Oren Freifeld, Eran Treister
ICML 2025 Clustering via Self-Supervised Diffusion.
Roy Uziel, Irit Chelly, Oren Freifeld, Ari Pakman
AISTATS 2025 Consistent Amortized Clustering via Generative Flow Networks.
Irit Chelly, Roy Uziel, Oren Freifeld, Ari Pakman
ECCV 2024 SpaceJAM: a Lightweight and Regularization-free Method for Fast Joint Alignment of Images.
Nir Barel*, Ron Shapira Weber*, Nir Mualem, Shahaf Finder, Oren Freifeld
ECCV 2024 Wavelet Convolutions for Large Receptive Fields.
Shahaf Finder, Roy Amoyal, Eran Treister, Oren Freifeld
ECCV 2024 Trainable Highly-expressive Activation Functions.
Irit Chelly*, Shahaf Finder*, Shira Ifergane, Oren Freifeld
NeurIPS 2023 From ViT Features to Training-free Video Object Segmentation via Streaming-data Mixture Models.
Roy Uziel, Or Dinari, Oren Freifeld
[ PDF ] [ Supplemental Material ] [ Code ]
ICML 2023 Regularization-free Diffeomorphic Temporal Alignment Nets.
Ron Shapira-Weber, Oren Freifeld
[ PDF (paper + Supplemental Material) ] [ Code ]
ECCV 2022 A Deep Moving-camera Background Model.
Guy Erez, Ron Shapira-Weber, Oren Freifeld
[ PDF ] [ Supplemental Material ] [ Code ]
UAI 2022 Revisiting DP-Means: Fast Scalable Algorithms via Parallelism and Delayed Cluster Creation.
Or Dinari, Oren Freifeld
[ PDF ] [ Code ]
UAI 2022 Variational- and Metric-based Deep Latent Space for Out-of-Distribution Detection.
Or Dinari, Oren Freifeld
[ PDF ] [ Code ]
CVPR 2022 DeepDPM: Deep Clustering With an Unknown Number of Clusters.
Meitar Ronen, Shahaf Finder, Oren Freifeld
[ PDF (Paper +Supplemental Material) ] [ Code ]
AISTATS 2022 Sampling in Dirichlet Process Mixture Models for Clustering Streaming Data.
Or Dinari, Oren Freifeld
[ PDF (Paper +Supplemental Material) ] [ Code (Julia) ] [ Code (Python) ] [ DataSets ] [ Example Notebook (Julia) ] [ Example Notebook (Python): Coming Soon ]
AISTATS 2022 Common Failure Modes of Subcluster-based Sampling in Dirichlet Process Gaussian Mixture Models and a Deep-learning Solution.
Vlad Winter*, Or Dinari*, Oren Freifeld
("*" indicates both these authors contributed equally)
[ PDF (Paper +Supplemental Material) ] [ Code ]
IEEE Access 2022 Effective Learning of a GMRF Mixture Model.
Shahaf Finder, Eran Treister, Oren Freifeld
[ PDF ] [ Code ]
ICIP 2021 Cyclic Diffeomorphic Transformer Nets for Contour Alignment.
Ilya Kaufman, Ron Shapira Weber, Oren Freifeld
[ PDF ] [ Code ]
UAI 2020 Scalable and Flexible Clustering of Grouped Data via Parallel and Distributed Sampling in Versatile Hierarchical Dirichlet Processes.
Or Dinari, Oren Freifeld
[ PDF ] [ Supplemental Material ] [ Code (Julia) ] [ Code (Python) ]
CVPR 2020 JA-POLS: a Moving-camera Background Model via Joint Alignment and Partially-overlapping Local Subspaces.
Irit Chelly, Vlad Winter, Dor Litvak, David Rosen, Oren Freifeld
[ PDF ] [ Supplemental Material ] [ Videos (example results) ] [ Code ]
NeurIPS 2019 Diffeomorphic Temporal Alignment Nets.
Ron Shapira Weber, Matan Eyal, Nicki Skafte Detlefsen, Oren Shriki, Oren Freifeld
[ PDF ] [ Supplemental Material ] [ Code ]
ICCV 2019 Bayesian Adaptive Superpixel Segmentation.
Roy Uziel, Meitar Ronen, Oren Freifeld
[ PDF ] [ Supplemental Material ] [ Code ]
HPML 2019 Distributed MCMC Inference in Dirichlet Process Mixture Models Using Julia.
Dinari, O.*, Yu, A.*, Freifeld, O., Fisher III, J.
("*" indicates both these authors contributed equally)
Best Paper Award
[ PDF ] [ Code (Julia) ] [ Code (Python) ]
CVPR 2018 Deep Diffeomorphic Transformer Networks.
Skafte Detlefsen, N., Freifeld, O., Hauberg, S.
[ PDF ] [ Supplemental Material ] [ Nicki Skafte Deftelsen's derivation of the matrix exponentials: PDF; Maple ] [ Code ]
IEEE-TPAMI 2018 The Manhattan Frame Model – Manhattan World Inference in the Space of Surface Normals.
Straub, J., Freifeld, O., Rosman, G., Leonard, J., Fisher III, J.
[ PDF ]
IEEE-TPAMI 2017 Transformations Based on Continuous Piecewise-Affine Velocity Fields.
Freifeld, O., Hauberg, S., Batmanghelich, K., Fisher III, J.
[ PDF ] [ Supplemental Material ] [ Technical Report: Deriving the CPAB Derivative (also includes fixing a small mistake in Eq 24 from the PAMI paper) ]
AISTATS 2016 Dreaming More Data: Class-dependent Distributions over Diffeomorphisms for Learned Data Augmentation.
Hauberg, S., Freifeld, O., Larsen, A.B.L., Fisher III, J., Hansen, L.K.
Accepted as Oral
[ PDF ] [ Video ] [ Datasets (AlignMNIST and AlignMNIST500) ]
ICCV 2015 Highly-Expressive Spaces of Well-Behaved Transformations: Keeping It Simple.
Freifeld, O., Hauberg, S., Batmanghelich, K., Fisher III, J.
[ PDF ] [ BibTex ] [ Project Webpage ] [ Supplemental Material ] [ Poster ] [ Code 1: uses GPU; requires an NVIDIA card; written in Python+CUDA ] [ Code 2: CPU-only; partial implementation; written in Julia ] [ Video 1: Conditional warp ] [ Video 2: spotlight ]
ICIP 2015 A Fast Method for Inferring High-Quality Simply-Connected Superpixels.
Freifeld, O., Li, Y., Fisher III, J.
Accepted as Oral. Recognized as one of the "Top 10% ICIP 2015 papers".
[ PDF ] [ BibTex ] [ Slides ] [ Project Webpage ] [ Code: CUDA + Python/C++/Matlab wrappers ] [ Remarks about the initialization+benchmarks ]
For additional examples in higher resolution than those in the paper:
[ original (~38MB) ] [ slightly compressed (~5MB) ]
AISTATS 2015 A Dirichlet Process Mixture Model for Spherical Data.
Straub, J., Chang, J., Freifeld, O., Fisher III, J.
Accepted as Oral
[ PDF ] [ BibTex ] [ Supplemental Material ] [ Code ]
CVPR 2014 A Mixture of Manhattan Frames: Beyond the Manhattan World.
Straub, J., Rosman, G., Freifeld, O., Leonard, J., Fisher III, J.
Accepted as Oral
[ PDF ] [ BibTex ] [ Project Webpage ] [ Supplemental Material ] [ Video ] [ Code ]
After the exposure it received in MIT News, this project was also covered by many technology/robotics websites.
CVPR 2014 Aerial Reconstructions via Probabilistic Data Fusion.
Cabezas, R., Freifeld, O., Rosman, G., Fisher III, J.
[ PDF ] [ BibTex ] [ Project Webpage ] [ Supplemental Material ] [ Video ] [ Code ] [ A 3D result reviewer ]
CVPR 2014 Model Transport: Towards Scalable Transfer Learning on Manifolds.
Freifeld, O., Hauberg, S., Black, M.J.
[ PDF ] [ BibTex ] [ Supplemental Material ] [ Video ] [ Remark about the data ]
J. Neural Engineering 2014 A freely-moving monkey treadmill model.
Foster, J.D., Nuyujukian, P., Freifeld, O., Gao, Walker, Ryu, S., Meng, T., Murmann, Black, M.J., Shenoy, K.V.
[ PDF (coming up soon) ] [ Project webpage at MPI-IS-PS ] [ Shenoy's group at Stanford EE ]
NIPS 2012 A Geometric take on Metric Learning.
Hauberg, S., Freifeld, O., Black, M.J.
[ PDF ] [ BibTex ] [ Project Webpage ] [ Supplemental Material ] [ Video ] [ Code ]
ECCV 2012 Lie Bodies: A Manifold Representation of 3D Human Shape.
Freifeld, O., Black, M.J.
[ PDF ] [ BibTex ] [ Project Webpage ] [ Supplemental Material ] [ Poster ] [ Video 1 ] [ Video 2 (~40 MB) ] [ Code ] [ Remark about the data ]
CVPR 2012 From pictorial structures to deformable structures.
Zuffi, S., Freifeld, O., Black, M.J.
[ PDF ] [ BibTex ] [ Project Webpage ] [ Code ]
IEEE-EMBC 2012 A framework for relating neural activity to freely moving behavior.
Foster, J.D., Nuyujukian, P., Freifeld, O., Ryu, S., Black, M.J., Shenoy, K.V.
Accepted as Oral
[ BibTex ]
IEEE-NER 2011 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.V.
Accepted as Oral
[ PDF ] [ BibTex ]
ECCV 2010 A 2D human body model dressed in eigen clothing.
Guan, P., Freifeld, O., Black, M.J.
[ PDF ] [ BibTex ] [ Data ]
CVPR 2010 Contour people: A parameterized model of 2D articulated human shape.
Freifeld, O., Weiss, A., Zuffi, S., Black, M.J.
Accepted as Oral
[ PDF ] [ BibTex ] [ Slides ] [ Talk's Video ]
Int. J. Biomed. Imaging 2009 Multiple Sclerosis lesion detection using constrained GMM and curve evolution.
Freifeld, O., Greenspan, H., Goldberger, J.
[ PDF ]
IEEE-ISBI 2007 Lesion detection in noisy MR brain images using constrained GMM and active contours.
Freifeld, O., Greenspan, H., Goldberger, J.
Accepted as Oral
[ PDF ] [ Slides ]

Theses

  1. Statistics on Manifolds with Applications to Modeling Shape Deformations. PhD Thesis, Brown University, August 2013.
    Freifeld, O.
    [
    PDF ] [ BibTex ] [ Eratta ]

  2. MR Brain Image Analysis: Healthy Tissue Segmentation and Multiple Sclerosis Lesion Detection Using Constrained GMM and Curve Evolution. MSc Thesis, Tel-Aviv University, July 2007.
    Freifeld, O.