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Related papers: Amplitude/Phase Retrieval for Terahertz Holography…

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By circumventing the resolution limitations of optics, coherent diffractive imaging (CDI) and ptychography are making their way into scientific fields ranging from X-ray imaging to astronomy. Yet, the need for time consuming iterative phase…

Computational Physics · Physics 2023-10-13 Oliver Hoidn , Aashwin Ananda Mishra , Apurva Mehta

In this paper, the problem of terahertz pulsed imaging and reconstruction is addressed. It is assumed that an incomplete (subsampled) three dimensional THz data set has been acquired and the aim is to recover all missing samples. A…

Computer Vision and Pattern Recognition · Computer Science 2015-06-17 Vahid Abolghasemi , Hao Shen , Yaochun Shen , Lu Gan

It is critical to characterize the carrier and instantaneous frequency distribution variation in ultrafast processes, all of which are determined by the optical phase. Nevertheless, there is no method that can single-shot record the…

Optics · Physics 2021-06-18 Wenchao Wang , Tianhao Xian , Li Zhan

A novel balanced air-biased coherent detection scheme for capturing ultrabroadband terahertz (THz) waveforms is implemented. The balanced detection scheme allows for coherent detection at the full repetition rate of the laser system without…

As a critical component of coherent X-ray diffraction imaging (CDI), phase retrieval has been extensively applied in X-ray structural science to recover the 3D morphological information inside measured particles. Despite meeting all the…

Image and Video Processing · Electrical Eng. & Systems 2021-10-29 Longlong Wu , Shinjae Yoo , Ana F. Suzana , Tadesse A. Assefa , Jiecheng Diao , Ross J. Harder , Wonsuk Cha , Ian K. Robinson

This paper proposes a novel algorithm for image phase retrieval, i.e., for recovering complex-valued images from the amplitudes of noisy linear combinations (often the Fourier transform) of the sought complex images. The algorithm is…

Signal Processing · Electrical Eng. & Systems 2018-10-19 Joshin P. Krishnan , José M. Bioucas-Dias , Vladimir Katkovnik

We propose and demonstrate a holographic imaging scheme exploiting random illuminations for recording hologram and then applying numerical reconstruction and twin removal. We use an in-line holographic geometry to record the hologram in…

Recent attempts to use deep learning for super-resolution reconstruction of turbulent flows have used supervised learning, which requires paired data for training. This limitation hinders more practical applications of super-resolution…

Fluid Dynamics · Physics 2021-02-03 Hyojin Kim , Junhyuk Kim , Sungjin Won , Changghoon Lee

Terahertz (THz) Time domain spectroscopy (THz-TDS) is a broadband spectroscopic technique spreading its uses in multiple fields: in science from material science to biology, in industry where it measures the thickness of a paint layer…

Applied Physics · Physics 2021-03-08 Sophie Eliet , Arnaud Cuisset , Francis Hindle , Jean-François Lampin , Romain Peretti

Phase retrieval is a well known ill-posed inverse problem where one tries to recover images given only the magnitude values of their Fourier transform as input. In recent years, new algorithms based on deep learning have been proposed,…

Image and Video Processing · Electrical Eng. & Systems 2022-04-21 Leon Gugel , Shai Dekel

Photoelectron holography constitutes a powerful tool for the ultrafast imaging of matter, as it combines high electron currents with subfemtosecond resolution, and gives information about transition amplitudes and phase shifts. Similarly to…

Atomic Physics · Physics 2020-02-19 C. Figueira de Morisson Faria , A. S. Maxwell

We propose a new algorithm to learn a dictionary for reconstructing and sparsely encoding signals from measurements without phase. Specifically, we consider the task of estimating a two-dimensional image from squared-magnitude measurements…

Optimization and Control · Mathematics 2016-11-23 Andreas M. Tillmann , Yonina C. Eldar , Julien Mairal

Detecting concealed chemicals and explosives remains a critical challenge in global security. Terahertz time-domain spectroscopy (THz-TDS) offers a promising non-invasive and stand-off detection technique owing to its ability to penetrate…

Optics · Physics 2025-12-05 Xinghe Jiang , Yuhang Li , Yuzhu Li , Che-Yung Shen , Aydogan Ozcan , Mona Jarrahi

Deep learning (DL) has emerged as a leading approach in accelerating MR imaging. It employs deep neural networks to extract knowledge from available datasets and then applies the trained networks to reconstruct accurate images from limited…

Image and Video Processing · Electrical Eng. & Systems 2024-02-06 Shanshan Wang , Ruoyou Wu , Sen Jia , Alou Diakite , Cheng Li , Qiegen Liu , Leslie Ying

In coherent X-ray diffraction microscopy the diffraction pattern generated by a sample illuminated with coherent x-rays is recorded, and a computer algorithm recovers the unmeasured phases to synthesize an image. By avoiding the use of a…

Phase retrieval algorithms have become an important component in many modern computational imaging systems. For instance, in the context of ptychography and speckle correlation imaging, they enable imaging past the diffraction limit and…

Machine Learning · Statistics 2018-07-03 Christopher A. Metzler , Philip Schniter , Ashok Veeraraghavan , Richard G. Baraniuk

Learning-based image super-resolution aims to reconstruct high-frequency (HF) details from the prior model trained by a set of high- and low-resolution image patches. In this paper, HF to be estimated is considered as a combination of two…

Computer Vision and Pattern Recognition · Computer Science 2016-11-18 Jian Zhang , Chen Zhao , Ruiqin Xiong , Siwei Ma , Debin Zhao

Deep Neural Network (DNN)-based image reconstruction, despite many successes, often exhibits uneven fidelity between high and low spatial frequency bands. In this paper we propose the Learning Synthesis by DNN (LS-DNN) approach where two…

Computer Vision and Pattern Recognition · Computer Science 2018-11-21 Mo Deng , Shuai Li , George Barbastathis

The increasing need of restoring high-resolution Hyper-Spectral (HS) images is determining a growing reliance on Computer Vision-based processing to enhance the clarity of the image content. HS images can, in fact, suffer from degradation…

Image and Video Processing · Electrical Eng. & Systems 2024-10-28 Marina Ljubenovic , Alessia Artesani , Stefano Bonetti , Arianna Traviglia

Hyperspectral (HS) images contain detailed spectral information that has proven crucial in applications like remote sensing, surveillance, and astronomy. However, because of hardware limitations of HS cameras, the captured images have low…

Image and Video Processing · Electrical Eng. & Systems 2021-06-15 Marija Vella , Bowen Zhang , Wei Chen , João F. C. Mota