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Reinhard Heckel

28 accepted papers

2026

Asymmetric Prompt Weighting for Reinforcement Learning with Verifiable Rewards

ICML 2026poster

Reinforcement learning with verifiable rewards has driven recent advances in LLM post-training, in particular for reasoning. Policy optimization algorithms generate a number of responses for a given prompt and then effectively weight the corresponding gradients depending on the rewards. The most pop…

Cited by 0SourceScholar
2026

OpenThoughts: Data Recipes for Reasoning Models

ICLR 2026oral

Reasoning models have made rapid progress on many benchmarks involving math, code, and science. Yet, there are still many open questions about the best train- ing recipes for reasoning since state-of-the-art models often rely on proprietary datasets with little to no public information available. To…

Cited by 0SourcecodeScholar
2026

Reliable Evaluation of MRI Motion Correction: Dataset and Insights

ICLR 2026poster

Correcting motion artifacts in scientific and medical imaging is important, as they significantly impact image quality. However, evaluating deep learning-based and classical motion correction methods remains fundamentally difficult due to the lack of accessible ground-truth target data. To address…

Cited by 0SourceScholar
2025

Efficient Noise Calculation in Deep Learning-based MRI Reconstructions

ICML 2025poster

Accelerated MRI reconstruction involves solving an ill-posed inverse problem where noise in acquired data propagates to the reconstructed images. Noise analyses are central to MRI reconstruction for providing an explicit measure of solution fidelity and for guiding the design and deployment of novel…

Cited by 0SourcePDFScholar
2025

Improving Deep Learning for Accelerated MRI With Data Filtering

NeurIPS 2025poster

Deep neural networks achieve state-of-the-art results for accelerated MRI reconstruction. Most research on deep learning based imaging focuses on improving neural network architectures trained and evaluated on fixed and homogeneous training and evaluation data. In this work, we investigate data cura…

Cited by 0SourceScholar
2025

Language models scale reliably with over-training and on downstream tasks

ICLR 2025poster

Scaling laws are useful guides for derisking expensive training runs, as they predict performance of large models using cheaper, small-scale experiments. However, there remain gaps between current scaling studies and how language models are ultimately trained and evaluated. For instance, scaling is…

2025

Measuring Fingerprints of Web-filtered Text Datasets and Fingerprint Propagation Through Training

NeurIPS 2025spotlight

We investigate fingerprints in pretraining datasets for large language models (LLMs) through dataset classification experiments. Building on prior work demonstrating the existence of fingerprints or biases in popular computer vision datasets, we analyze popular open-source pretraining datasets for L…

Cited by 0SourceScholar
2024

DataComp-LM: In search of the next generation of training sets for language models

NeurIPS 2024poster

We introduce DataComp for Language Models, a testbed for controlled dataset experiments with the goal of improving language models. As part of DCLM, we provide a standardized corpus of 240T tokens extracted from Common Crawl, effective pretraining recipes based on the OpenLM framework, and a broad s…

Cited by 64SourcePDFScholar
2024

MotionTTT: 2D Test-Time-Training Motion Estimation for 3D Motion Corrected MRI

NeurIPS 2024poster

A major challenge of the long measurement times in magnetic resonance imaging (MRI), an important medical imaging technology, is that patients may move during data acquisition. This leads to severe motion artifacts in the reconstructed images and volumes. In this paper, we propose MotionTTT a deep l…

2024

Robustness of Deep Learning for Accelerated MRI: Benefits of Diverse Training Data

ICML 2024poster

Deep learning based methods for image reconstruction are state-of-the-art for a variety of imaging tasks. However, neural networks often perform worse if the training data differs significantly from the data they are applied to. For example, a model trained for accelerated magnetic resonance imaging…

2024

TTT-MIM: Test-Time Training with Masked Image Modeling for Denoising Distribution Shifts

ECCV 2024poster

"Neural networks trained end-to-end give state-of-the-art performance for image denoising. However, when applied to an image outside of the training distribution, the performance often degrades significantly. In this work, we propose a test-time training (TTT) method based on masked image modeling (…

2023

Analyzing the Sample Complexity of Self-Supervised Image Reconstruction Methods

NeurIPS 2023poster

Supervised training of deep neural networks on pairs of clean image and noisy measurement achieves state-of-the-art performance for many image reconstruction tasks, but such training pairs are difficult to collect. Self-supervised methods enable training based on noisy measurements only, without cle…

2023

Learning Provably Robust Estimators for Inverse Problems via Jittering

NeurIPS 2023poster

Deep neural networks provide excellent performance for inverse problems such as denoising. However, neural networks can be sensitive to adversarial or worst-case perturbations. This raises the question of whether such networks can be trained efficiently to be worst-case robust. In this paper, we inv…

2022

Test-Time Training Can Close the Natural Distribution Shift Performance Gap in Deep Learning Based Compressed Sensing

ICML 2022spotlight

Deep learning based image reconstruction methods outperform traditional methods. However, neural networks suffer from a performance drop when applied to images from a different distribution than the training images. For example, a model trained for reconstructing knees in accelerated magnetic resona…

2021

Data augmentation for deep learning based accelerated MRI reconstruction with limited data

ICML 2021spotlight

Deep neural networks have emerged as very successful tools for image restoration and reconstruction tasks. These networks are often trained end-to-end to directly reconstruct an image from a noisy or corrupted measurement of that image. To achieve state-of-the-art performance, training on large and…

Cited by 77SourcePDFScholar
2021

Early Stopping in Deep Networks: Double Descent and How to Eliminate it

ICLR 2021poster

Over-parameterized models, such as large deep networks, often exhibit a double descent phenomenon, whereas a function of model size, error first decreases, increases, and decreases at last. This intriguing double descent behavior also occurs as a function of training epochs and has been conjectured…

2021

Interpolation can hurt robust generalization even when there is no noise

NeurIPS 2021poster

Numerous recent works show that overparameterization implicitly reduces variance for min-norm interpolators and max-margin classifiers. These findings suggest that ridge regularization has vanishing benefits in high dimensions. We challenge this narrative by showing that, even in the absence of noi…

2021

Measuring Robustness in Deep Learning Based Compressive Sensing

ICML 2021oral

Deep neural networks give state-of-the-art accuracy for reconstructing images from few and noisy measurements, a problem arising for example in accelerated magnetic resonance imaging (MRI). However, recent works have raised concerns that deep-learning-based image reconstruction methods are sensitive…

2020

Compressive sensing with un-trained neural networks: Gradient descent finds a smooth approximation

ICML 2020poster

Un-trained convolutional neural networks have emerged as highly successful tools for image recovery and restoration. They are capable of solving standard inverse problems such as denoising and compressive sensing with excellent results by simply fitting a neural network model to measurements from a…

2019

A Fast and Robust Paradigm for Fourier Compressed Sensing Based on Coded Sampling

ICASSP 2019accepted

First-order gradient methods are commonly used for compressed sensing reconstruction. However, for Fourier sampling systems, they require computing a large number of fast Fourier transforms (FFTs), which can be expensive in real-time applications. In this paper, instead of random sub-sampling, we us…

Cited by 0SourceScholar
2019

Adaptive Estimation for Approximate $k$-Nearest-Neighbor Computations

AISTATS 2019poster

Algorithms often carry out equally many computations for "easy" and "hard" problem instances. In particular, algorithms for finding nearest neighbors typically have the same running time regardless of the particular problem instance. In this paper, we consider the approximate $k$-nearest-neighbor p…

2019

Deep Decoder: Concise Image Representations from Untrained Non-convolutional Networks

ICLR 2019poster

Deep neural networks, in particular convolutional neural networks, have become highly effective tools for compressing images and solving inverse problems including denoising, inpainting, and reconstruction from few and noisy measurements. This success can be attributed in part to their ability to re…

2018

Approximate Ranking from Pairwise Comparisons

AISTATS 2018poster

A common problem in machine learning is to rank a set of n items based on pairwise comparison. Here, ranking refers to partitioning the items into sets of pre-specified sizes according to theirs scores, which includes identification of the top-k items as the most prominent special case. The score o…

Cited by 0SourcePDFScholar