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Related papers: Amplitude/Phase Retrieval for Terahertz Holography…

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We propose a new spectrum allocation strategy, aided by unsupervised learning, for multiuser terahertz communication systems. In this strategy, adaptive sub-band bandwidth is considered such that the spectrum of interest can be divided into…

Machine Learning · Computer Science 2024-10-28 Akram Shafie , Chunhui Li , Nan Yang , Xiangyun Zhou , Trung Q. Duong

Current supervised cross-domain image retrieval methods can achieve excellent performance. However, the cost of data collection and labeling imposes an intractable barrier to practical deployment in real applications. In this paper, we…

Computer Vision and Pattern Recognition · Computer Science 2022-07-21 Conghui Hu , Gim Hee Lee

Metasurfaces are optically thin metamaterials that promise complete control of the wavefront of light but are primarily used to control only the phase of light. Here, we present an approach, simple in concept and in practice, that uses…

Recently, computational sampling methods have been implemented to spatially characterize terahertz (THz) fields. Previous methods usually rely on either specialized THz devices such as THz spatial light modulators, or complicated systems…

Optics · Physics 2019-06-19 Jiapeng Zhao , Yiwen E , Kaia Williams , Xi-cheng Zhang , Robert Boyd

It is demonstrated that an object distribution can be successfully retrieved from its diffraction pattern or hologram, even if some of the measured intensity samples are missing. The maximum allowable number of missing values depends on the…

Image and Video Processing · Electrical Eng. & Systems 2019-08-28 Tatiana Latychevskaia

Intense terahertz (THz) electromagnetic fields have been utilized to reveal a variety of extremely nonlinear optical effects in many materials through nonperturbative driving of elementary and collective excitations. However, such nonlinear…

The remarkable success in face forgery techniques has received considerable attention in computer vision due to security concerns. We observe that up-sampling is a necessary step of most face forgery techniques, and cumulative up-sampling…

Computer Vision and Pattern Recognition · Computer Science 2021-03-11 Honggu Liu , Xiaodan Li , Wenbo Zhou , Yuefeng Chen , Yuan He , Hui Xue , Weiming Zhang , Nenghai Yu

Computer-generated holograms (CGHs) are used in holographic three-dimensional (3D) displays and holographic projections. The quality of the reconstructed images using phase-only CGHs is degraded because the amplitude of the reconstructed…

Computer Vision and Pattern Recognition · Computer Science 2022-02-02 Yoshiyuki Ishii , Tomoyoshi Shimobaba , David Blinder , Tobias Birnbaum , Peter Schelkens , Takashi Kakue , Tomoyoshi Ito

In tomographic reconstruction, the image quality of the reconstructed images can be significantly degraded by defects in the measured two-dimensional (2D) raw image data. Despite the importance of screening defective 2D images for robust…

Image and Video Processing · Electrical Eng. & Systems 2019-10-29 Donghun Ryu , Youngju Jo , Jihyeong Yoo , Taean Chang , Daewoong Ahn , Young Seo Kim , Geon Kim , Hyun-seok Min , Yongkeun Park

Image dehazing without paired haze-free images is of immense importance, as acquiring paired images often entails significant cost. However, we observe that previous unpaired image dehazing approaches tend to suffer from performance…

Image and Video Processing · Electrical Eng. & Systems 2020-07-13 Chen Liu , Jiaqi Fan , Guosheng Yin

The challenge of imaging low-density objects in an electron microscope without causing beam damage is significant in modern TEM. This is especially true for life science imaging, where the sample, rather than the instrument, still…

Optics · Physics 2025-01-29 Francisco Vega Ibáñez , Jo Verbeeck

The problem of phase retrieval (PR) involves recovering an unknown image from limited amplitude measurement data and is a challenge nonlinear inverse problem in computational imaging and image processing. However, many of the PR methods are…

Computer Vision and Pattern Recognition · Computer Science 2023-09-11 Aoxu Liu , Xiaohong Fan , Yin Yang , Jianping Zhang

Fourier phase retrieval is a classical problem of restoring a signal only from the measured magnitude of its Fourier transform. Although Fienup-type algorithms, which use prior knowledge in both spatial and Fourier domains, have been widely…

Computer Vision and Pattern Recognition · Computer Science 2020-11-23 Eunju Cha , Chanseok Lee , Mooseok Jang , Jong Chul Ye

We present a temporally-multiplexed dual-colour terahertz (THz) imaging technique using THz-to-optical conversion in atomic vapour. By rapidly alternating the pump laser frequency, we sequentially excite two atomic states, each absorbing a…

Atomic Physics · Physics 2025-07-16 Lucy A. Downes , C. Stuart Adams , Kevin J. Weatherill

Super-resolution fluorescence microscopy provides unprecedented insight into cellular and subcellular structures. However, going "beyond the diffraction barrier" comes at a price since most far-field super-resolution imaging techniques…

Purpose: To introduce a novel deep learning based approach for fast and high-quality dynamic multi-coil MR reconstruction by learning a complementary time-frequency domain network that exploits spatio-temporal correlations simultaneously…

Image and Video Processing · Electrical Eng. & Systems 2021-06-21 Chen Qin , Jinming Duan , Kerstin Hammernik , Jo Schlemper , Thomas Küstner , René Botnar , Claudia Prieto , Anthony N. Price , Joseph V. Hajnal , Daniel Rueckert

Aiming at improving the performance of existing detection algorithms developed for different applications, we propose a region regression-based multi-stage class-agnostic detection pipeline, whereby the existing algorithms are employed for…

Computer Vision and Pattern Recognition · Computer Science 2016-07-19 Wei Li , Matthias Breier , Dorit Merhof

Hand-held light field (LF) cameras often exhibit low spatial resolution due to the inherent trade-off between spatial and angular dimensions. Existing supervised learning-based LF spatial super-resolution (SR) methods, which rely on…

Image and Video Processing · Electrical Eng. & Systems 2025-12-09 Jianxin Lei , Dongze Wu , Chengcai Xu , Hongcheng Gu , Guangquan Zhou , Junhui Hou , Ping Zhou

The Fourier inversion of phased coherent diffraction patterns offers images without the resolution and depth-of-focus limitations of lens-based tomographic systems. We report on our recent experimental images inverted using recent…

Phase retrieval (PR) concerns the recovery of complex phases from complex magnitudes. We identify the connection between the difficulty level and the number and variety of symmetries in PR problems. We focus on the most difficult far-field…

Computer Vision and Pattern Recognition · Computer Science 2022-11-03 Zhong Zhuang , David Yang , Felix Hofmann , David Barmherzig , Ju Sun
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