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The lensing effect of the cosmic microwave background (CMB) is a powerful tool for our study of the distribution of matter in the universe. Currently, the quadratic estimator (EQ) method, which is widely used to reconstruct lensing…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-26 Ye-Peng Yan , Guo-Jian Wang , Si-Yu Li , Yang-Jie Yan , Jun-Qing Xia

Bayesian image restoration has had a long history of successful application but one of the limitations that has prevented more widespread use is that the methods are generally computationally intensive. The authors recently addressed this…

Methodology · Statistics 2023-06-02 Karl Young , John Kornak , Eric Friedman

We consider the 2D wavelet transform with two scales to study sky maps of temperature anisotropies in the cosmic microwave background radiation (CMB). We apply this technique to simulated maps of small sky patches of size 12.8 \times 12.8…

Radio polarisation images of the jets of Active Galactic Nuclei (AGN) can provide a deep insight into the launching and collimation mechanisms of relativistic jets. However, even at VLBI scales, resolution is often a limiting factor in the…

Astrophysics of Galaxies · Physics 2016-09-07 Colm P. Coughlan , Denise C. Gabuzda

Medical imaging modalities including magnetic resonance imaging (MRI), computed tomography (CT), and ultrasound are essential for accurate diagnosis and treatment planning in modern healthcare. However, noise contamination during image…

Image and Video Processing · Electrical Eng. & Systems 2025-08-22 Asadullah Bin Rahman , Masud Ibn Afjal , Md. Abdulla Al Mamun

An overview is given of Bayesian inversion and regularization procedures. In particular, the conceptual basis of the maximum entropy method (MEM) is discussed, and extensions to positive/negative and complex data are highlighted. Other…

Astrophysics · Physics 2009-11-06 A. N. Lasenby , R. B. Barreiro , M. P. Hobson

We apply the iterative Expectation-Maximization algorithm (EM) to estimate the power spectrum of the CMB from multifrequency microwave maps. In addition, we are also able to provide a reconstruction of the CMB map. By assuming that the…

Astrophysics · Physics 2009-11-07 E. Martinez-Gonzalez , J. M. Diego , P. Vielva , J. Silk

The delensing of cosmic microwave background (CMB) maps will be increasingly valuable for extracting as much information as possible from future CMB surveys. Delensing provides many general benefits, including sharpening of the acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-20 Cynthia Trendafilova , Selim C. Hotinli , Joel Meyers

We revisit the impact of finite time responses of bolometric detectors used for deep observations of the cosmic microwave background (CMB). Until now, bolometer transfer functions have been accounted for through a two-step procedure by…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-21 A. Basyrov , N. O. Stutzer , J. G. S. Lunde , H. K. Eriksen , E. Gjerløw , D. J. Watts , I. K. Wehus

Image restoration is a fundamental and challenging task in computer vision, where CNN-based frameworks demonstrate significant computational efficiency. However, previous CNN-based methods often face challenges in adequately restoring fine…

Computer Vision and Pattern Recognition · Computer Science 2025-10-30 Shengyu Zhu , Congyi Fan , Fuxuan Zhang

Low-light images suffer from complex degradation, and existing enhancement methods often encode all degradation factors within a single latent space. This leads to highly entangled features and strong black-box characteristics, making the…

Computer Vision and Pattern Recognition · Computer Science 2025-07-17 Shuangli Du , Siming Yan , Zhenghao Shi , Zhenzhen You , Lu Sun

The cosmic microwave background (CMB) is a significant source of knowledge about the origin and evolution of our universe. However, observations of the CMB are contaminated by foreground emissions, obscuring the CMB signal and reducing its…

Machine Learning · Computer Science 2023-02-27 Jadie Adams , Steven Lu , Krzysztof M. Gorski , Graca Rocha , Kiri L. Wagstaff

In Image Compression, the researchers' aim is to reduce the number of bits required to represent an image by removing the spatial and spectral redundancies. Recently discrete wavelet transform and wavelet packet has emerged as popular…

Computer Vision and Pattern Recognition · Computer Science 2010-04-20 G. K. Kharate , V. H. Patil

The accurate reconstruction of Cosmic Microwave Background (CMB) maps and the measurement of its power spectrum are crucial for studying the early universe. In this paper, we implement a convolutional neural network to apply the Wiener…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-07 Belén Costanza , Claudia G. Scóccola , Matías Zaldarriaga

We consider wavelets as a tool to perform a variety of tasks in the context of analyzing cosmic microwave background (CMB) maps. Using Spherical Haar Wavelets we define a position and angular-scale-dependent measure of power that can be…

Astrophysics · Physics 2009-10-31 L. Tenorio , A. H. Jaffe , S. Hanany , C. H. Lineweaver

We describe a new map-making code for cosmic microwave background (CMB) observations. It implements fast algorithms for convolution and transpose convolution of two functions on the sphere (Wandelt & G\'{o}rski 2001). Our code can account…

Astrophysics · Physics 2009-11-10 Charmaine Armitage , Benjamin D. Wandelt

We investigate the use of wavelet transforms in detecting and characterising non-Gaussian structure in maps of the cosmic microwave background (CMB). We apply the method to simulated maps of the Kaiser-Stebbins effect due to cosmic strings…

Astrophysics · Physics 2009-10-31 MP Hobson , AW Jones , AN Lasenby

Deep image registration has demonstrated exceptional accuracy and fast inference. Recent advances have adopted either multiple cascades or pyramid architectures to estimate dense deformation fields in a coarse-to-fine manner. However, due…

Computer Vision and Pattern Recognition · Computer Science 2024-07-19 Xinxing Cheng , Xi Jia , Wenqi Lu , Qiufu Li , Linlin Shen , Alexander Krull , Jinming Duan

Deep convolutional neural networks (CNNs) are used for image denoising via automatically mining accurate structure information. However, most of existing CNNs depend on enlarging depth of designed networks to obtain better denoising…

Image and Video Processing · Electrical Eng. & Systems 2022-10-04 Chunwei Tian , Menghua Zheng , Wangmeng Zuo , Bob Zhang , Yanning Zhang , David Zhang

Image enhancement is a technique that frequently utilized in digital image processing. In recent years, the popularity of learning-based techniques for enhancing the aesthetic performance of photographs has increased. However, the majority…

Computer Vision and Pattern Recognition · Computer Science 2022-12-20 Zinuo Li , Xuhang Chen , Chi-Man Pun , Shuqiang Wang