Quantitative MR image reconstruction using parameter-specific dictionary learning with adaptive dictionary-size and sparsity-level choice

A Kofler, KM Kerkering, L Göschel… - IEEE Transactions …, 2023 - ieeexplore.ieee.org
Objective: We propose a method for the reconstruction of parameter-maps in Quantitative
Magnetic Resonance Imaging (QMRI). Methods: Because different quantitative parameter …

Deep supervised dictionary learning by algorithm unrolling—Application to fast 2D dynamic MR image reconstruction

A Kofler, MC Pali, T Schaeffter, C Kolbitsch - Medical Physics, 2023 - Wiley Online Library
Abstract Background Unrolled neural networks (NNs) have been extensively applied to
different image reconstruction problems across all imaging modalities. A key component of …

Adaptive sparsity level and dictionary size estimation for image reconstruction in accelerated 2D radial cine MRI

MC Pali, T Schaeffter, C Kolbitsch, A Kofler - Medical Physics, 2021 - Wiley Online Library
Purpose In the past, dictionary learning (DL) and sparse coding (SC) have been proposed
for the regularization of image reconstruction problems. The regularization is given by a …

Average performance of OMP and Thresholding under dictionary mismatch

MC Pali, S Ruetz, K Schnass - IEEE Signal Processing Letters, 2022 - ieeexplore.ieee.org
This paper studies the performance of OMP in comparison to Thresholding in the case in
which only a perturbed version of the generating dictionary is known. Both theory and …

Adaptive-size dictionary learning using Information Theoretic Criteria

B Dumitrescu, CD Giurcăneanu - Algorithms, 2019 - mdpi.com
Finding the size of the dictionary is an open issue in dictionary learning (DL). We propose an
algorithm that adapts the size during the learning process by using Information Theoretic …

Machine Learning for Quantitative MR Image Reconstruction

A Kofler, FF Zimmermann, K Papafitsoros - arXiv preprint arXiv …, 2024 - arxiv.org
In the last years, the design of image reconstruction methods in the field of quantitative
Magnetic Resonance Imaging (qMRI) has experienced a paradigm shift. Often, when …

Convergence of alternating minimisation algorithms for dictionary learning

S Ruetz, K Schnass - arXiv preprint arXiv:2304.01768, 2023 - arxiv.org
In this paper we derive sufficient conditions for the convergence of two popular alternating
minimisation algorithms for dictionary learning-the Method of Optimal Directions (MOD) and …

基于字典尺度自适应学习的欠定盲语音重构算法.

李嘉新, 魏爽, 俞守庚, 刘睿 - Telecommunication …, 2023 - search.ebscohost.com
针对欠定盲语音分离传统字典学习算法不能优化字典尺寸的问题, 提出了一种尺度自适应同步码
字优化(Scale Adaptive Simultaneous Codeword Optimization, SASimCO) 算法 …

Dictionary learning for signals in additive noise with generalized Gaussian distribution

X Zheng, B Dumitrescu, J Liu, CD Giurcăneanu - Signal Processing, 2022 - Elsevier
We propose a dictionary learning (DL) algorithm for signals in additive noise with
generalized Gaussian distribution (GGD) by redesigning three key components used in DL …

[PDF][PDF] Dictionary learning & sparse modelling

MC Pali - 2021 - uibk.ac.at
One of the key findings on which many signal processing tasks are built is that even high-
dimensional signals admit some kind of sparse representation in a suitable generator …