Hannes Nickisch

ORCID: 0000-0003-1604-6647
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About
Contact & Profiles
Research Areas
  • Gaussian Processes and Bayesian Inference
  • Medical Imaging Techniques and Applications
  • Advanced X-ray and CT Imaging
  • Radiomics and Machine Learning in Medical Imaging
  • Cardiac Imaging and Diagnostics
  • Sparse and Compressive Sensing Techniques
  • Coronary Interventions and Diagnostics
  • COVID-19 diagnosis using AI
  • Advanced MRI Techniques and Applications
  • Medical Image Segmentation Techniques
  • Lung Cancer Diagnosis and Treatment
  • Solar and Space Plasma Dynamics
  • Control Systems and Identification
  • Bayesian Modeling and Causal Inference
  • Oceanographic and Atmospheric Processes
  • Blind Source Separation Techniques
  • Domain Adaptation and Few-Shot Learning
  • Bayesian Methods and Mixture Models
  • Advanced Image and Video Retrieval Techniques
  • Radiology practices and education
  • Ionosphere and magnetosphere dynamics
  • Image and Signal Denoising Methods
  • Artificial Intelligence in Healthcare and Education
  • Machine Learning and Data Classification
  • Advanced Multi-Objective Optimization Algorithms

Philips (Germany)
2015-2024

Philips (India)
2021-2023

University of Oslo
2021-2022

Philips (United States)
2016-2019

Philips (Israel)
2017

Philips (Finland)
2011-2015

Philips (Spain)
2013

Max Planck Institute for Biological Cybernetics
2006-2012

Max Planck Institute for Intelligent Systems
2010-2012

Max Planck Society
2006-2011

We study the problem of object classification when training and test classes are disjoint, i.e. no examples target available. This setup has hardly been studied in computer vision research, but it is rule rather than exception, because world contains tens thousands different for only a very few them image, collections have formed annotated with suitable class labels. In this paper, we tackle by introducing attribute-based classification. It performs detection based on human-specified...

10.1109/cvprw.2009.5206594 article EN 2009 IEEE Conference on Computer Vision and Pattern Recognition 2009-06-01

We study the problem of object recognition for categories which we have no training examples, a task also called zero--data or zero-shot learning. This situation has hardly been studied in computer vision research, even though it occurs frequently; world contains tens thousands different classes, and image collections formed suitably annotated only few them. To tackle problem, introduce attribute-based classification: Objects are identified based on high-level description that is phrased...

10.1109/tpami.2013.140 article EN IEEE Transactions on Pattern Analysis and Machine Intelligence 2013-07-30

We study the problem of object classification when training and test classes are disjoint, i.e. no examples target available. This setup has hardly been studied in computer vision research, but it is rule rather than exception, because world contains tens thousands different for only a very few them image, collections have formed annotated with suitable class labels. In this paper, we tackle by introducing attribute-based classification. It performs detection based on human-specified...

10.1109/cvpr.2009.5206594 article EN 2009 IEEE Conference on Computer Vision and Pattern Recognition 2009-06-01

The GPML toolbox provides a wide range of functionality for Gaussian process (GP) inference and prediction. GPs are specified by mean covariance functions; we offer library simple functions mechanisms to compose more complex ones. Several likelihood supported including heavy-tailed regression as well others suitable classification. Finally, methods is provided, exact variational inference, Expectation Propagation, Laplace's method dealing with non-Gaussian likelihoods FITC large tasks.

10.5555/1756006.1953029 article EN Journal of Machine Learning Research 2010-03-01

The increased availability of labeled X-ray image archives (e.g. ChestX-ray14 dataset) has triggered a growing interest in deep learning techniques. To provide better insight into the different approaches, and their applications to chest classification, we investigate powerful network architecture detail: ResNet-50. Building on prior work this domain, consider transfer with without fine-tuning as well training dedicated from scratch. leverage high spatial resolution data, also include an...

10.1038/s41598-019-42294-8 article EN cc-by Scientific Reports 2019-04-22

Abstract The optimization of k ‐space sampling for nonlinear sparse MRI reconstruction is phrased as a Bayesian experimental design problem. inference approximated by novel relaxation to standard signal processing primitives, resulting in an efficient algorithm Cartesian and spiral trajectories. On clinical resolution brain image data from Siemens 3T scanner, automatically optimized trajectories lead significantly improved images, compared low‐pass, equispaced, or variable density randomized...

10.1002/mrm.22180 article EN Magnetic Resonance in Medicine 2009-10-26

We relate compressed sensing (CS) with Bayesian experimental design and provide a novel efficient approximate method for the latter, based on expectation propagation. In large comparative study about linearly measuring natural images, we show that simple standard heuristic of wavelet coefficients top-down systematically outperforms CS methods using random measurements; sequential projection optimisation approach (Ji & Carin, 2007) performs even worse. also our own is able to learn...

10.1145/1390156.1390271 article EN 2008-01-01

We introduce a framework and early results for massively scalable Gaussian processes (MSGP), significantly extending the KISS-GP approach of Wilson Nickisch (2015). The MSGP enables use (GPs) on billions datapoints, without requiring distributed inference, or severe assumptions. In particular, reduces standard $O(n^3)$ complexity GP learning inference to $O(n)$, $O(n^2)$ per test point prediction $O(1)$. involves 1) decomposing covariance matrices as Kronecker products Toeplitz approximated...

10.48550/arxiv.1511.01870 preprint EN other-oa arXiv (Cornell University) 2015-01-01

Purpose Subject motion can severely degrade MR images. A retrospective correction algorithm, Gradient‐based correction, which significantly reduces ghosting and blurring artifacts due to subject was proposed. The technique uses the raw data of standard imaging sequences; no sequence modifications or additional equipment such as tracking devices are required. Rigid is assumed. Methods approach iteratively searches for trajectory yielding sharpest image measured by entropy spatial gradients....

10.1002/mrm.24615 article EN Magnetic Resonance in Medicine 2013-02-11

Abstract Based on their salient features we manually label 5,824 images from various Time History of Events and Macroscale Interactions during Substorms (THEMIS) all‐sky imagers; the labels use are clear/no aurora , cloudy moon arc diffuse discrete . We then a pretrained deep neural network to automatically extract 1,001‐dimensional feature vector these images. Together, vectors used train ridge classifier that is able correctly predict category unseen auroral based extracted with 82%...

10.1029/2018ja025274 article EN cc-by-nc-nd Journal of Geophysical Research Space Physics 2018-06-09

Abstract Objective The aim is to evaluate whether smart worklist prioritization by artificial intelligence (AI) can optimize the radiology workflow and reduce report turnaround times (RTATs) for critical findings in chest radiographs (CXRs). Furthermore, we investigate a method counteract effect of false negative predictions AI—resulting an extremely dangerously long RTAT, as CXRs are sorted end worklist. Methods We developed simulation framework that models current at university hospital...

10.1007/s00330-020-07480-7 article EN cc-by European Radiology 2020-11-21

Many problems of low-level computer vision and image processing, such as denoising, deconvolution, tomographic reconstruction or superresolution, can be addressed by maximizing the posterior distribution a sparse linear model (SLM). We show how higher-order Bayesian decision-making problems, optimizing acquisition in magnetic resonance scanners, querying SLM covariance, unrelated to density's mode. propose scalable algorithmic framework, with which posteriors over full, high-resolution...

10.1137/090758775 article EN SIAM Journal on Imaging Sciences 2011-01-01

For applications as varied Bayesian neural networks, determinantal point processes, elliptical graphical models, and kernel learning for Gaussian processes (GPs), one must compute a log determinant of an $n \times n$ positive definite matrix, its derivatives - leading to prohibitive $\mathcal{O}(n^3)$ computations. We propose novel $\mathcal{O}(n)$ approaches estimating these quantities from only fast matrix vector multiplications (MVMs). These stochastic approximations are based on...

10.48550/arxiv.1711.03481 preprint EN other-oa arXiv (Cornell University) 2017-01-01

Physiological nonrigid motion is inevitable when imaging, e.g., abdominal viscera, and can lead to serious deterioration of the image quality. Prospective techniques for correction handle only special types motion, as they allow global correction. Retrospective methods developed so far need guidance from navigator sequences or external sensors. We propose a fully retrospective scheme that needs raw data an input.Our method based on forward model describes effects by partitioning into patches...

10.1002/mrm.25266 article EN Magnetic Resonance in Medicine 2014-04-23

We develop an open source algorithm to apply Transfer learning Aurora image classification and Magnetic disturbance Evaluation (TAME). For this purpose, we evaluate the performance of 80 pretrained neural networks using Oslo Auroral THEMIS (OATH) data set all-sky images, both in terms runtime their features' predictive capability. From features extracted by best network, retrain last network layer Support Vector Machine (SVM) distinguish between labels "arc," "diffuse," "discrete," "cloud,"...

10.1029/2021ja029683 article EN Journal of Geophysical Research Space Physics 2021-12-16

Deep neural networks have emerged as the preferred method for semantic segmentation of CT images in recent years. However, understanding their limitations and generalization properties remains an active area research a relevant topic clinical applications. One crucial factor among many is X-ray radiation dose, which always kept low reasonably possible during acquisition. Therefore, potential dose reductions may pose challenge existing models. In this paper, we investigate robustness recently...

10.1117/12.3000186 article EN Medical Imaging 2022: Image Processing 2024-04-02
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