Convolutional Dictionary Learning by End-To-End Training of Iterative
Neural Networks
- URL: http://arxiv.org/abs/2206.04447v1
- Date: Thu, 9 Jun 2022 12:15:38 GMT
- Title: Convolutional Dictionary Learning by End-To-End Training of Iterative
Neural Networks
- Authors: Andreas Kofler, Christian Wald, Tobias Schaeffter, Markus Haltmeier,
Christoph Kolbitsch
- Abstract summary: In this work, we construct an INN which can be used as a supervised and physics-informed online convolutional dictionary learning algorithm.
We show that the proposed INN improves over two conventional model-agnostic training methods and yields competitive results also compared to a deep INN.
- Score: 3.6280929178575994
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: Sparsity-based methods have a long history in the field of signal processing
and have been successfully applied to various image reconstruction problems.
The involved sparsifying transformations or dictionaries are typically either
pre-trained using a model which reflects the assumed properties of the signals
or adaptively learned during the reconstruction - yielding so-called blind
Compressed Sensing approaches. However, by doing so, the transforms are never
explicitly trained in conjunction with the physical model which generates the
signals. In addition, properly choosing the involved regularization parameters
remains a challenging task. Another recently emerged training-paradigm for
regularization methods is to use iterative neural networks (INNs) - also known
as unrolled networks - which contain the physical model. In this work, we
construct an INN which can be used as a supervised and physics-informed online
convolutional dictionary learning algorithm. We evaluated the proposed approach
by applying it to a realistic large-scale dynamic MR reconstruction problem and
compared it to several other recently published works. We show that the
proposed INN improves over two conventional model-agnostic training methods and
yields competitive results also compared to a deep INN. Further, it does not
require to choose the regularization parameters and - in contrast to deep INNs
- each network component is entirely interpretable.
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