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In traditional compressed sensing theory, the dictionary matrix is given a priori, whereas in real applications this matrix suffers from random noise and fluctuations. In this paper we consider a signal model where each column in the…

Information Theory · Computer Science 2015-06-17 Zhao Tan , Peng Yang , Arye Nehorai

In this paper, we introduce a dictionary learning based approach applied to the problem of real-time reconstruction of MR image sequences that are highly undersampled in k-space. Unlike traditional dictionary learning, our method integrates…

Computer Vision and Pattern Recognition · Computer Science 2015-02-19 Dornoosh Zonoobi , Shahrooz Faghih Roohi , Ashraf A. Kassim

Large pre-trained transformers have revolutionized artificial intelligence across various domains, and fine-tuning remains the dominant approach for adapting these models to downstream tasks due to the cost of training from scratch.…

Computer Vision and Pattern Recognition · Computer Science 2025-07-16 Wei Chen , Jingxi Yu , Zichen Miao , Qiang Qiu

The celebrated sparse representation model has led to remarkable results in various signal processing tasks in the last decade. However, despite its initial purpose of serving as a global prior for entire signals, it has been commonly used…

Information Theory · Computer Science 2017-10-11 Vardan Papyan , Jeremias Sulam , Michael Elad

Dictionary learning consists of finding a sparse representation from noisy data and is a common way to encode data-driven prior knowledge on signals. Alternating minimization (AM) is standard for the underlying optimization, where gradient…

Machine Learning · Computer Science 2022-02-09 Benoît Malézieux , Thomas Moreau , Matthieu Kowalski

Sparse Representation (SR) of signals or data has a well founded theory with rigorous mathematical error bounds and proofs. SR of a signal is given by superposition of very few columns of a matrix called Dictionary, implicitly reducing…

Computer Vision and Pattern Recognition · Computer Science 2026-04-01 G. Madhuri , Atul Negi

Hyperspectral images have far more spectral bands than ordinary multispectral images. Rich band information provides more favorable conditions for the tremendous applications. However, significant increase in the dimensionality of spectral…

Computer Vision and Pattern Recognition · Computer Science 2018-02-21 Fei Li , Pingping Zhang , Huchuan Lu

The sparsity of natural signals and images in a transform domain or dictionary has been extensively exploited in several applications such as compression, denoising and inverse problems. More recently, data-driven adaptation of synthesis…

Machine Learning · Computer Science 2017-04-24 Saiprasad Ravishankar , Raj Rao Nadakuditi , Jeffrey A. Fessler

We propose a new algorithm for hyperparameter selection in machine learning algorithms. The algorithm is a novel modification of Harmonica, a spectral hyperparameter selection approach using sparse recovery methods. In particular, we show…

Machine Learning · Computer Science 2019-04-26 Minsu Cho , Chinmay Hegde

Over the past few years, dictionary learning (DL)-based methods have been successfully used in various image reconstruction problems. However, traditional DL-based computed tomography (CT) reconstruction methods are patch-based and ignore…

Dictionary learning can be used for image superresolution by learning a pair of coupled dictionaries of image patches from high-resolution and low-resolution image pairs such that the corresponding pairs share the same sparse vector when…

Computer Vision and Pattern Recognition · Computer Science 2023-08-08 Antonio Castro

Sparse coding--that is, modelling data vectors as sparse linear combinations of basis elements--is widely used in machine learning, neuroscience, signal processing, and statistics. This paper focuses on the large-scale matrix factorization…

Machine Learning · Statistics 2010-02-11 Julien Mairal , Francis Bach , Jean Ponce , Guillermo Sapiro

The sparse generalized eigenvalue problem arises in a number of standard and modern statistical learning models, including sparse principal component analysis, sparse Fisher discriminant analysis, and sparse canonical correlation analysis.…

Numerical Analysis · Computer Science 2019-03-05 Ganzhao Yuan , Li Shen , Wei-Shi Zheng

Super-symmetric tensors - a higher-order extension of scatter matrices - are becoming increasingly popular in machine learning and computer vision for modelling data statistics, co-occurrences, or even as visual descriptors. However, the…

Computer Vision and Pattern Recognition · Computer Science 2015-09-11 Piotr Koniusz , Anoop Cherian

This paper proposes an efficient example sampling method for example-based word sense disambiguation systems. To construct a database of practical size, a considerable overhead for manual sense disambiguation (overhead for supervision) is…

Computation and Language · Computer Science 2007-05-23 Atsushi Fujii , Kentaro Inui , Takenobu Tokunaga , Hozumi Tanaka

Recently, sparsity-based algorithms are proposed for super-resolution spectrum estimation. However, to achieve adequately high resolution in real-world signal analysis, the dictionary atoms have to be close to each other in frequency,…

Machine Learning · Statistics 2015-06-05 Yiyuan She , Huanghuang Li , Jiangping Wang , Dapeng Wu

A good measure of similarity between data points is crucial to many tasks in machine learning. Similarity and metric learning methods learn such measures automatically from data, but they do not scale well respect to the dimensionality of…

Machine Learning · Computer Science 2019-09-10 Kuan Liu , Aurélien Bellet , Fei Sha

Sparse dictionary learning (DL) has emerged as a powerful approach to extract semantically meaningful concepts from the internals of large language models (LLMs) trained mainly in the text domain. In this work, we explore whether DL can…

Incorporating sparsity priors in learning tasks can give rise to simple, and interpretable models for complex high dimensional data. Sparse models have found widespread use in structure discovery, recovering data from corruptions, and a…

Machine Learning · Statistics 2014-03-27 Karthikeyan Natesan Ramamurthy , Aleksandr Y. Aravkin , Jayaraman J. Thiagarajan

In several applications, input samples are more naturally represented in terms of similarities between each other, rather than in terms of feature vectors. In these settings, machine-learning algorithms can become very computationally…

Computer Vision and Pattern Recognition · Computer Science 2017-12-19 Ambra Demontis , Marco Melis , Battista Biggio , Giorgio Fumera , Fabio Roli
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