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Tolga Birdal

59 accepted papers

2026

Adversarial Vulnerability from Interference Between Features in Superposition

ICML 2026poster

Why do adversarial examples exist, and why do they transfer between models? Existing explanations appeal to high-dimensional geometry, non-robust patterns in the input, and decision boundary structure, but none provides a representation-level mechanism that explains why specific perturbations succee…

Cited by 0SourceScholar
2026

Correlations in the Data Lead to Semantically Rich Feature Geometry Under Superposition

ICLR 2026poster

Recent advances in mechanistic interpretability have shown that many features represented by deep learning models can be captured by dictionary learning approaches such as sparse autoencoders. However, our understanding of the structures formed by these internal representations is still limited. Ini…

Cited by 0SourcecodeScholar
2026

DisPOSE: Projected Polystochastic Diffusion for Self-Supervised Multi-View 3D Human Pose Estimation

ICML 2026poster

Recovering 3D human poses for multiple individuals from different camera views is a fundamental bottleneck for analyzing interacting behaviors. Existing self-supervised approaches leverage synthetic catalogues of 3D poses; however, this leads to poor generalization in real-world scenarios due to dis…

Cited by 0SourceScholar
2026

Geometric Neural Distance Fields for Learning Human Motion Priors

CVPR 2026

We introduce Neural Riemannian Motion Fields (\name), a novel 3D generative human motion prior that enables robust, temporally consistent, and physically plausible 3D motion recovery. Unlike existing VAE or diffusion-based methods, our higher-order motion prior explicitly models the human motion in

Cited by 0SourceScholar
2026

Learning on Higher-Order Structures with Effective Operators

ICML 2026poster

Higher-order structures are powerful relational modeling tools, yet existing spectral operators decompose topology into separate ranks, leaving practitioners to fuse information back to vertices through ad-hoc choices. We introduce _Collapsed Effective Operators_, which marginalize higher-order stru…

Cited by 0SourceScholar
2026

MoLingo: Motion-Language Alignment for Text-to-Human Motion Generation

CVPR 2026

We introduce MoLingo, a text-to-motion (T2M) model that generates realistic, lifelike human motion by denoising in a continuous latent space. Recent works perform latent space diffusion, either on the whole latent at once or auto-regressively over multiple latents. In this paper, we study how to mak

Cited by 0SourceScholar
2026

On the Interaction of Compressibility and Adversarial Robustness

ICLR 2026poster

Modern neural networks are expected to simultaneously satisfy a host of desirable properties: accurate fitting to training data, generalization to unseen inputs, parameter and computational efficiency, and robustness to adversarial perturbations. While compressibility and robustness have each been s…

Cited by 0SourceScholar
2026

Parallelised Differentiable Straightest Geodesics for 3D Meshes

CVPR 2026

Machine learning has been progressively generalised to operate within non-Euclidean domains, but geometrically accurate methods for learning on surfaces are still falling behind. The lack of closed-form Riemannian operators, the non-differentiability of their discrete counterparts, and poor parallel

Cited by 0SourceScholar
2025

A Flag Decomposition for Hierarchical Datasets

CVPR 2025poster

Flag manifolds encode nested sequences of subspaces and serve as powerful structures for various computer vision and machine learning applications. Despite their utility in tasks such as dimensionality reduction, motion averaging, and subspace clustering, current applications are often restricted to…

2025

Convex Formulations for Training Two-Layer ReLU Neural Networks

ICLR 2025poster

Solving non-convex, NP-hard optimization problems is crucial for training machine learning models, including neural networks. However, non-convexity often leads to black-box machine learning models with unclear inner workings. While convex formulations have been used for verifying neural network rob…

2025

Copresheaf Topological Neural Networks: A Generalized Deep Learning Framework

NeurIPS 2025poster

We introduce copresheaf topological neural networks (CTNNs), a powerful unifying framework that encapsulates a wide spectrum of deep learning architectures, designed to operate on structured data, including images, point clouds, graphs, meshes, and topological manifolds. While deep learning has prof…

Cited by 0SourceScholar
2025

CuMPerLay: Learning Cubical Multiparameter Persistence Vectorizations

ICCV 2025poster

We present CuMPerLay, a novel differentiable vectorization layer that enables the integration of Cubical Multiparameter Persistence (CMP) into deep learning pipelines. While CMP presents a natural and powerful way to topologically work with images, its use is hindered by the complexity of multifiltr…

2025

Dyn-HaMR: Recovering 4D Interacting Hand Motion from a Dynamic Camera

CVPR 2025highlight

We propose Dyn-HaMR, to the best of our knowledge, the first approach to reconstruct 4D global hand motion from monocular videos recorded by dynamic cameras in the wild. Reconstructing accurate 3D hand meshes from monocular videos is a crucial task for understanding human behaviour, with significant…

Cited by 1SourcePDFScholar
2025

Forecasting Continuous Non-Conservative Dynamical Systems in SO(3)

ICCV 2025poster

Modeling the rotation of moving objects is a fundamental task in computer vision, yet SO(3) extrapolation still presents numerous challenges: (1) unknown quantities such as the moment of inertia complicate dynamics, (2) the presence of external forces and torques can lead to non-conservative kinemat…

Cited by 0SourcePDFScholar
2025

Fractional Diffusion Bridge Models

NeurIPS 2025poster

We present *Fractional Diffusion Bridge Models* (FDBM), a novel generative diffusion bridge framework driven by the rich and non-Markovian fractional Brownian motion (fBM). Real stochastic processes exhibit a degree of memory effects (correlations in time), long-range dependencies, roughness and ano…

Cited by 0SourceScholar
2025

Grokking at the Edge of Numerical Stability

ICLR 2025poster

Grokking, or sudden generalization that occurs after prolonged overfitting, is a surprising phenomenon that has challenged our understanding of deep learning. While a lot of progress has been made in understanding grokking, it is still not clear why generalization is delayed and why grokking often d…

2025

Large Learning Rates Simultaneously Achieve Robustness to Spurious Correlations and Compressibility

ICCV 2025poster

Robustness and resource-efficiency are two highly desirable properties for modern machine learning models. However, achieving them jointly remains a challenge. In this paper, we identify high learning rates as a facilitator for simultaneously achieving robustness to spurious correlations and network…

2025

Towards Dynamic 3D Reconstruction of Hand-Instrument Interaction in Ophthalmic Surgery

NeurIPS 2025spotlight

Accurate 3D reconstruction of hands and instruments is critical for vision-based analysis of ophthalmic microsurgery, yet progress has been hampered by the lack of realistic, large-scale datasets and reliable annotation tools. In this work, we introduce OphNet-3D, the first extensive RGB-D dynamic 3…

Cited by 0SourceScholar
2024

Alignist: CAD-Informed Orientation Distribution Estimation by Fusing Shape and Correspondences

ECCV 2024poster

"Object pose distribution estimation is crucial in robotics for better path planning and handling of symmetric objects. Recent distribution estimation approaches employ contrastive learning-based approaches by maximizing the likelihood of a single pose estimate in the absence of a CAD model. We prop…

2024

Fun with Flags: Robust Principal Directions via Flag Manifolds

CVPR 2024poster

Principal component analysis (PCA) along with its extensions to manifolds and outlier contaminated data have been indispensable in computer vision and machine learning. In this work we present a unifying formalism for PCA and its variants and introduce a framework based on the flags of linear subspa…

2024

Generative Fractional Diffusion Models

NeurIPS 2024poster

We introduce the first continuous-time score-based generative model that leverages fractional diffusion processes for its underlying dynamics. Although diffusion models have excelled at capturing data distributions, they still suffer from various limitations such as slow convergence, mode-collapse o…

2024

HyperSDFusion: Bridging Hierarchical Structures in Language and Geometry for Enhanced 3D Text2Shape Generation

CVPR 2024poster

3D shape generation from text is a fundamental task in 3D representation learning. The text-shape pairs exhibit a hierarchical structure where a general text like "chair" covers all 3D shapes of the chair while more detailed prompts refer to more specific shapes. Furthermore both text and 3D shapes…

2024

NRDF: Neural Riemannian Distance Fields for Learning Articulated Pose Priors

CVPR 2024highlight

Faithfully modeling the space of articulations is a crucial task that allows recovery and generation of realistic poses and remains a notorious challenge. To this end we introduce Neural Riemannian Distance Fields (NRDFs) data-driven priors modeling the space of plausible articulations represented a…

Cited by 11SourcePDFScholar
2024

Position: Topological Deep Learning is the New Frontier for Relational Learning

ICML 2024poster

Topological deep learning (TDL) is a rapidly evolving field that uses topological features to understand and design deep learning models. This paper posits that TDL is the new frontier for relational learning. TDL may complement graph representation learning and geometric deep learning by incorporat…

Cited by 40SourcePDFScholar
2024

Probabilistic Sampling of Balanced K-Means using Adiabatic Quantum Computing

CVPR 2024poster

Adiabatic quantum computing (AQC) is a promising approach for discrete and often NP-hard optimization problems. Current AQCs allow to implement problems of research interest which has sparked the development of quantum representations for many computer vision tasks. Despite requiring multiple measur…

Cited by 1SourcePDFScholar
2024

SignAvatars: A Large-scale 3D Sign Language Holistic Motion Dataset and Benchmark

ECCV 2024poster

"We present SignAvatars1 , the first large-scale, multi-prompt 3D sign language (SL) motion dataset designed to bridge the communication gap for Deaf and hard-of-hearing individuals. While there has been an exponentially growing number of research regarding digital communication, the majority of exi…

2024

Topological Generalization Bounds for Discrete-Time Stochastic Optimization Algorithms

NeurIPS 2024poster

We present a novel set of rigorous and computationally efficient topology-based complexity notions that exhibit a strong correlation with the generalization gap in modern deep neural networks (DNNs). DNNs show remarkable generalization properties, yet the source of these capabilities remains elusive…

Cited by 6SourcePDFScholar
2024

UV-free Texture Generation with Denoising and Geodesic Heat Diffusion

NeurIPS 2024poster

Seams, distortions, wasted UV space, vertex-duplication, and varying resolution over the surface are the most prominent issues of the standard UV-based texturing of meshes. These issues are particularly acute when automatic UV-unwrapping techniques are used. For this reason, instead of generating te…

2024

Variational Inference for SDEs Driven by Fractional Noise

ICLR 2024spotlight

We present a novel variational framework for performing inference in (neural) stochastic differential equations (SDEs) driven by Markov-approximate fractional Brownian motion (fBM). SDEs offer a versatile tool for modeling real-world continuous-time dynamic systems with inherent noise and randomness…

Cited by 6SourcePDFScholar
2023

VidStyleODE: Disentangled Video Editing via StyleGAN and NeuralODEs

ICCV 2023poster

We propose VidStyleODE, a spatiotemporally continuous disentangled video representation based upon StyleGAN and Neural-ODEs. Effective traversal of the latent space learned by Generative Adversarial Networks (GANs) has been the basis for recent breakthroughs in image editing. However, the applicabil…

Cited by 2PDFScholar
2022

Point2Cyl: Reverse Engineering 3D Objects From Point Clouds to Extrusion Cylinders

CVPR 2022poster

We propose Point2Cyl, a supervised network transforming a raw 3D point cloud to a set of extrusion cylinders. Reverse engineering from a raw geometry to a CAD model is an essential task to enable manipulation of the 3D data in shape editing software and thus expand their usages in many downstream ap…

Cited by 64PDFScholar
2022

Projective Manifold Gradient Layer for Deep Rotation Regression

CVPR 2022poster

Regressing rotations on SO(3) manifold using deep neural networks is an important yet unsolved problem. The gap between the Euclidean network output space and the non-Euclidean SO(3) manifold imposes a severe challenge for neural network learning in both forward and backward passes. While several wo…

Cited by 32PDFcodeScholar
2022

Q-FW: A Hybrid Classical-Quantum Frank-Wolfe for Quadratic Binary Optimization

ECCV 2022poster

"We present a hybrid classical-quantum framework based on the Frank-Wolfe algorithm, Q-FW, for solving quadratic, linearly-constrained, binary optimization problems on quantum annealers (QA). The computational premise of quantum computers has cultivated the re-design of various existing vision probl…

2021

HuMoR: 3D Human Motion Model for Robust Pose Estimation

ICCV 2021poster

We introduce HuMoR: a 3D Human Motion Model for Robust Estimation of temporal pose and shape. Though substantial progress has been made in estimating 3D human motion and shape from dynamic observations, recovering plausible pose sequences in the presence of noise and occlusions remains a challenge.…

Cited by 354PDFcodeScholar
2021

Intrinsic Dimension, Persistent Homology and Generalization in Neural Networks

NeurIPS 2021poster

Disobeying the classical wisdom of statistical learning theory, modern deep neural networks generalize well even though they typically contain millions of parameters. Recently, it has been shown that the trajectories of iterative optimization algorithms can possess \emph{fractal structures}, and the…

2021

MultiBodySync: Multi-Body Segmentation and Motion Estimation via 3D Scan Synchronization

CVPR 2021poster

We present MultiBodySync, a novel, end-to-end trainable multi-body motion segmentation and rigid registration framework for multiple input 3D point clouds. The two non-trivial challenges posed by this multi-scan multibody setting that we investigate are: (i) guaranteeing correspondence and segmentat…

Cited by 57PDFcodeScholar
2021

Weakly Supervised Learning of Rigid 3D Scene Flow

CVPR 2021poster

We propose a data-driven scene flow estimation algorithm exploiting the observation that many 3D scenes can be explained by a collection of agents moving as rigid bodies. At the core of our method lies a deep architecture able to reason at the object-level by considering 3D scene flow in conjunction…

Cited by 114PDFcodeScholar
2020

6D Camera Relocalization in Ambiguous Scenes via Continuous Multimodal Inference

ECCV 2020poster

We present a multimodal camera relocalization framework that captures ambiguities and uncertainties with continuous mixture models defined on the manifold of camera poses. In highly ambiguous environments, which can easily arise due to symmetries and repetitive structures in the scene, computing one…

2020

CaSPR: Learning Canonical Spatiotemporal Point Cloud Representations

NeurIPS 2020spotlight

We propose CaSPR, a method to learn object-centric Canonical Spatiotemporal Point Cloud Representations of dynamically moving or evolving objects. Our goal is to enable information aggregation over time and the interrogation of object state at any spatiotemporal neighborhood in the past, observed or…

2020

Deformation-Aware 3D Model Embedding and Retrieval

ECCV 2020poster

We introduce a new problem of mph{retrieving} 3D models that are mph{deformable} to a given query shape and present a novel deep mph{deformation-aware} embedding to solve this retrieval task. 3D model retrieval is a fundamental operation for recovering a clean and complete 3D model from a noisy and…

2020

From Planes to Corners: Multi-Purpose Primitive Detection in Unorganized 3D Point Clouds

RA-L 2020

We propose anew method for segmentation-free joint estimation of orthogonal planes, their intersection lines, relationship graph and corners lying at the intersection of three orthogonal planes. Such unified scene exploration under orthogonality allows for multitudes of applications such as semantic

Cited by 12SourcecodeScholar
2020

Learning Multiview 3D Point Cloud Registration

CVPR 2020poster

We present a novel, end-to-end learnable, multiview 3D point cloud registration algorithm. Registration of multiple scans typically follows a two-stage pipeline: the initial pairwise alignment and the globally consistent refinement. The former is often ambiguous due to the low overlap of neighboring…

Cited by 220PDFcodeScholar
2020

Quaternion Equivariant Capsule Networks for 3D Point Clouds

ECCV 2020poster

We present a 3D capsule module for processing point clouds that is equivariant to 3D rotations and translations, as well as invariant to permutations of the input points. The operator receives a sparse set of local reference frames, computed from an input point cloud and establishes end-to-end trans…

Cited by 112SourcePDFScholar
2020

Synchronizing Probability Measures on Rotations via Optimal Transport

CVPR 2020poster

We introduce a new paradigm, `measure synchronization', for synchronizing graphs with measure-valued edges. We formulate this problem as maximization of the cycle-consistency in the space of probability measures over relative rotations. In particular, we aim at estimating marginal distributions of a…

Cited by 37PDFScholar
2019

Explaining the Ambiguity of Object Detection and 6D Pose From Visual Data

ICCV 2019poster

3D object detection and pose estimation from a single image are two inherently ambiguous problems. Oftentimes, objects appear similar from different viewpoints due to shape symmetries, occlusion and repetitive textures. This ambiguity in both detection and pose estimation means that an object instan…

Cited by 138PDFScholar
2019

Probabilistic Permutation Synchronization Using the Riemannian Structure of the Birkhoff Polytope

CVPR 2019oral

We present an entirely new geometric and probabilistic approach to synchronization of correspondences across multiple sets of objects or images. In particular, we present two algorithms: (1) Birkhoff-Riemannian L-BFGS for optimizing the relaxed version of the combinatorially intractable cycle consis…

Cited by 42PDFScholar
2018

A Minimalist Approach to Type-Agnostic Detection of Quadrics in Point Clouds

CVPR 2018poster

This paper proposes a segmentation-free, automatic and efficient procedure to detect general geometric quadric forms in point clouds, where clutter and occlusions are inevitable. Our everyday world is dominated by man-made objects which are designed using 3D primitives (such as planes, cones, sphere…

Cited by 15SourcePDFScholar
2018

Bayesian Pose Graph Optimization via Bingham Distributions and Tempered Geodesic MCMC

NeurIPS 2018poster

We introduce Tempered Geodesic Markov Chain Monte Carlo (TG-MCMC) algorithm for initializing pose graph optimization problems, arising in various scenarios such as SFM (structure from motion) or SLAM (simultaneous localization and mapping). TG-MCMC is first of its kind as it unites global non-convex…

Cited by 42SourcePDFScholar
2018

PPF-FoldNet: Unsupervised Learning of Rotation Invariant 3D Local Descriptors

ECCV 2018poster

We present PPF-FoldNet for unsupervised learning of 3D local descriptors on pure point cloud geometry. Based on the folding-based auto-encoding of well known point pair features, PPF-FoldNet offers many desirable properties: it necessitates neither supervision, nor a sensitive local reference frame,…

Cited by 476SourcePDFScholar
2018

PPFNet: Global Context Aware Local Features for Robust 3D Point Matching

CVPR 2018poster

We present PPFNet - Point Pair Feature NETwork for deeply learning a globally informed 3D local feature descriptor to find correspondences in unorganized point clouds. PPFNet learns local descriptors on pure geometry and is highly aware of the global context, an important cue in deep learning. Our 3…

Cited by 764SourcePDFScholar