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Images taken by space telescopes typically have a superb spatial resolution, but a relatively poor sampling rate due to the finite CCD pixel size. Beyond the Nyquist limit, it becomes uncertain how much the pixelation effect may affect the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-06 Zhi Shen , Jun Zhang , Hekun Li , Haoran Wang , Chengliang Wei , Guoliang Li , Xiaobo Li , Zhang Ban , Dan Yue

Sparse-view computed tomography (CT) is an effective method to reduce the radiation exposure in medical imaging. To reduce the severe streaking artifacts that occur in reconstructed images due to violation of the Nyquist/Shannon sampling…

Medical Physics · Physics 2026-03-17 Huiying Li , Yizhuang Song

This contribution introduces a novel signal extrapolation algorithm and its application to image error concealment. The signal extrapolation is carried out by iteratively generating a model of the signal suffering from distortion. Thereby,…

Image and Video Processing · Electrical Eng. & Systems 2022-07-15 Jürgen Seiler , André Kaup

Surface reconstruction from sparse views aims to reconstruct a 3D shape or scene from few RGB images. The latest methods are either generalization-based or overfitting-based. However, the generalization-based methods do not generalize well…

Computer Vision and Pattern Recognition · Computer Science 2025-08-04 Liang Han , Xu Zhang , Haichuan Song , Kanle Shi , Yu-Shen Liu , Zhizhong Han

In the field of signal processing, the sampling theorem plays a fundamental role for signal reconstruction as it bridges the gap between analog and digital signals. Following the celebrated Nyquist-Shannon sampling theorem, generalizing the…

Information Theory · Computer Science 2024-07-23 Zhexuan Zeng , Jun Liu , Ye Yuan

This work concerns sampling of smooth signals on arbitrary graphs. We first study a structured sampling strategy for such smooth graph signals that consists of a random selection of few pre-defined groups of nodes. The number of groups to…

Social and Information Networks · Computer Science 2017-05-08 Gilles Puy , Patrick Pérez

We propose a new technique to obtain super-resolution images with radio interferometer using sparse modeling. In standard radio interferometry, sampling of ($u$, $v$) is quite often incomplete and thus obtaining an image from observed…

Instrumentation and Methods for Astrophysics · Physics 2014-07-10 Mareki Honma , Kazunori Akiyama , Makoto Uemura , Shiro Ikeda

Sparse representation of 3D images is considered within the context of data reduction. The goal is to produce high quality approximations of 3D images using fewer elementary components than the number of intensity points in the 3D array.…

Image and Video Processing · Electrical Eng. & Systems 2019-06-12 Laura Rebollo-Neira , Daniel Whitehouse

Image segmentation is an important component of many image understanding systems. It aims to group pixels in a spatially and perceptually coherent manner. Typically, these algorithms have a collection of parameters that control the degree…

Computer Vision and Pattern Recognition · Computer Science 2018-02-02 Marc Bosch , Christopher M. Gifford , Austin G. Dress , Clare W. Lau , Jeffrey G. Skibo , Gordon A. Christie

In an era of unprecedented deluge of (mostly unstructured) data, graphs are proving more and more useful, across the sciences, as a flexible abstraction to capture complex relationships between complex objects. One of the main challenges…

Disordered Systems and Neural Networks · Physics 2016-10-17 Alaa Saade

Diffusion-based inpainting is a powerful tool for the reconstruction of images from sparse data. Its quality strongly depends on the choice of known data. Optimising their spatial location -- the inpainting mask -- is challenging. A…

Image and Video Processing · Electrical Eng. & Systems 2022-05-17 Tobias Alt , Pascal Peter , Joachim Weickert

Few-shot image classification remains challenging due to the scarcity of labeled training examples. Augmenting them with synthetic data has emerged as a promising way to alleviate this issue, but models trained on synthetic samples often…

Machine Learning · Computer Science 2025-06-26 Lan-Cuong Nguyen , Quan Nguyen-Tri , Bang Tran Khanh , Dung D. Le , Long Tran-Thanh , Khoat Than

Quarter sampling is a novel sensor concept that enables the acquisition of higher resolution images without increasing the number of pixels. This is achieved by covering three quarters of each pixel of a low-resolution sensor such that only…

Image and Video Processing · Electrical Eng. & Systems 2022-03-02 Simon Grosche , Kristian Fischer , Fabian Brand , Jürgen Seiler , André Kaup

Controllable spherical panoramic image generation holds substantial applicative potential across a variety of domains.However, it remains a challenging task due to the inherent spherical distortion and geometry characteristics, resulting in…

Computer Vision and Pattern Recognition · Computer Science 2024-03-18 Tao Wu , Xuewei Li , Zhongang Qi , Di Hu , Xintao Wang , Ying Shan , Xi Li

We propose a group sparse optimization model for inpainting of a square-integrable isotropic random field on the unit sphere, where the field is represented by spherical harmonics with random complex coefficients. In the proposed…

Optimization and Control · Mathematics 2022-05-10 Chao Li , Xiaojun Chen

Many computer vision systems require low-cost segmentation algorithms based on deep learning, either because of the enormous size of input images or limited computational budget. Common solutions uniformly downsample the input images to…

Computer Vision and Pattern Recognition · Computer Science 2022-08-19 Chen Jin , Ryutaro Tanno , Thomy Mertzanidou , Eleftheria Panagiotaki , Daniel C. Alexander

We propose a novel method of efficient upsampling of a single natural image. Current methods for image upsampling tend to produce high-resolution images with either blurry salient edges, or loss of fine textural detail, or spurious noise…

Computer Vision and Pattern Recognition · Computer Science 2015-03-03 Chinmay Hegde , Oncel Tuzel , Fatih Porikli

The Compressive Sensing (CS) as a novel acquisition approach that finds its usage in image processing. The hypothesis like this one assures signal recovery with high quality from decreased number of samples compared with the number required…

Signal Processing · Electrical Eng. & Systems 2019-03-06 Drazen Jelic , Ana Scekic , Melvudin Hot , Nemanja Sevaljevic

A successful approach to image quality assessment involves comparing the structural information between a distorted and its reference image. However, extracting structural information that is perceptually important to our visual system is a…

Computer Vision and Pattern Recognition · Computer Science 2021-03-17 Tanaya Guha , Ehsan Nezhadarya , Rabab K Ward

In traditional optical imaging systems, the spatial resolution is limited by the physics of diffraction, which acts as a low-pass filter. The information on sub-wavelength features is carried by evanescent waves, never reaching the camera,…

Optics · Physics 2018-12-13 Oren Solomon , Yonina C. Eldar , Maor Mutzafi , Mordechai Segev