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This paper concerns iterative reconstruction for low-dose and few-view CT by minimizing a data-fidelity term regularized with the Total Variation (TV) penalty. We propose a very fast iterative algorithm to solve this problem. The algorithm…

Medical Physics · Physics 2017-02-01 Hiroyuki Kudo , Fukashi Yamazaki , Takuya Nemoto , Keita Takaki

In this report, we applied expectation and maximization (EM) method described by Philips et al [1] to recover two-dimensional (2D) structure from multiple sparse signal images in random orientation. The detailed derivation of EM algorithm…

Data Analysis, Statistics and Probability · Physics 2017-01-12 Yun Zhao

Inverse ellipsometry, i.e., reconstructing optical constants and film thickness from the measured phase difference $\Delta$ and amplitude ratio $\Psi$, is a fundamentally ill-posed problem. Traditional solutions rely on slow, expert-driven…

Machine Learning · Computer Science 2026-03-20 Yiming Ma , Jianzhi Teng , Xinjie Li , Xin Sun , Zhiyong Wang , Yuzhou Song , Lionel Z. Wang , Bin Chen

Denoising of coefficients in a sparse domain (e.g. wavelet) has been researched extensively because of its simplicity and effectiveness. Literature mainly has focused on designing the best global threshold. However, this paper proposes a…

Image and Video Processing · Electrical Eng. & Systems 2018-01-03 Hamid Reza Shahdoosti

The use of machine-learning in neuroimaging offers new perspectives in early diagnosis and prognosis of brain diseases. Although such multivariate methods can capture complex relationships in the data, traditional approaches provide…

Conventional algorithms for sparse signal recovery and sparse representation rely on $l_1$-norm regularized variational methods. However, when applied to the reconstruction of $\textit{sparse images}$, i.e., images where only a few pixels…

Computer Vision and Pattern Recognition · Computer Science 2016-05-09 Sohil Shah , Tom Goldstein , Christoph Studer

Diffusion models have emerged as potential tools to tackle the challenge of sparse-view CT reconstruction, displaying superior performance compared to conventional methods. Nevertheless, these prevailing diffusion models predominantly focus…

Image and Video Processing · Electrical Eng. & Systems 2023-09-06 Kai Xu , Shiyu Lu , Bin Huang , Weiwen Wu , Qiegen Liu

State-of-the-art atmospheric turbulence image restoration methods utilize standard image processing tools such as optical flow, lucky region and blind deconvolution to restore the images. While promising results have been reported over the…

Image and Video Processing · Electrical Eng. & Systems 2019-05-21 Nicholas Chimitt , Zhiyuan Mao , Guanzhe Hong , Stanley H. Chan

In the context of optical interferometry, only undersampled power spectrum and bispectrum data are accessible. It poses an ill-posed inverse problem for image recovery. Recently, a tri-linear model was proposed for monochromatic imaging,…

Instrumentation and Methods for Astrophysics · Physics 2017-07-11 Jasleen Birdi , Audrey Repetti , Yves Wiaux

Wavelet functions allow the sparse and efficient representation of a signal at different scales. Recently the application of wavelets to the denoising of maps of cosmic microwave background (CMB) fluctuations has been proposed. The…

Astrophysics · Physics 2009-11-07 Klaus Maisinger , M. P. Hobson , A. N. Lasenby

We introduce a method for fast estimation of data-adapted, spatio-temporally dependent regularization parameter-maps for variational image reconstruction, focusing on total variation (TV)-minimization. Our approach is inspired by recent…

This work is concerned with applying iterative image reconstruction, based on constrained total-variation minimization, to low-intensity X-ray CT systems that have a high sampling rate. Such systems pose a challenge for iterative image…

Medical Physics · Physics 2016-11-17 Emil Y. Sidky , Rick Chartrand , Yuval Duchin , Christer Ullberg , Xiaochuan Pan

When smartphone cameras are used to take photos of digital screens, usually moire patterns result, severely degrading photo quality. In this paper, we design a wavelet-based dual-branch network (WDNet) with a spatial attention mechanism for…

Computer Vision and Pattern Recognition · Computer Science 2020-07-20 Lin Liu , Jianzhuang Liu , Shanxin Yuan , Gregory Slabaugh , Ales Leonardis , Wengang Zhou , Qi Tian

We solve a weakly supervised regression problem. Under "weakly" we understand that for some training points the labels are known, for some unknown, and for others uncertain due to the presence of random noise or other reasons such as lack…

Machine Learning · Computer Science 2021-04-15 Vladimir Berikov , Alexander Litvinenko

In this paper, we propose a Riemannian steepest descent method for solving a blind deconvolution problem. We prove that the proposed algorithm with an appropriate initialization will recover the exact solution with high probability when the…

Information Theory · Computer Science 2018-04-17 Wen Huang , Paul Hand

The development of computed tomography (CT) image reconstruction methods that significantly reduce patient radiation exposure while maintaining high image quality is an important area of research in low-dose CT (LDCT) imaging. We propose a…

Machine Learning · Statistics 2019-06-14 Xuehang Zheng , Saiprasad Ravishankar , Yong Long , Jeffrey A. Fessler

Kernel-free quadratic surface support vector machines (QSVM) have recently gained traction due to their flexibility in modeling nonlinear decision boundaries without relying on kernel functions. However, the introduction of a full quadratic…

Machine Learning · Computer Science 2026-03-09 Ahmad Mousavi , Ramin Zandvakili , Zheming Gao

Removal of noise from an image is an extensively studied problem in image processing. Indeed, the recent advent of sophisticated and highly effective denoising algorithms lead some to believe that existing methods are touching the ceiling…

Computer Vision and Pattern Recognition · Computer Science 2017-09-05 Yaniv Romano , Michael Elad , Peyman Milanfar

We propose an adaptive regularization scheme in a variational framework where a convex composite energy functional is optimized. We consider a number of imaging problems including denoising, segmentation and motion estimation, which are…

Computer Vision and Pattern Recognition · Computer Science 2017-03-01 Byung-Woo Hong , Ja-Keoung Koo , Hendrik Dirks , Martin Burger

Image restoration under adverse weather conditions refers to the process of removing degradation caused by weather particles while improving visual quality. Most existing deweathering methods rely on increasing the network scale and data…

Computer Vision and Pattern Recognition · Computer Science 2025-03-04 Zihan Shen , Yu Xuan , Qingyu Yang
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