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Related papers: Dual-wavelength Fourier Ptychographic Topography

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Ptychography is a popular imaging technique that combines diffractive imaging with scanning microscopy. The technique consists of a coherent beam that is scanned across an object in a series of overlapping positions, leading to reliable and…

Numerical Analysis · Mathematics 2024-08-08 Ricardo Parada , Samy Wu Fung , Stanley Osher

Phase reconstruction is important in transmission electron microscopy for structural studies. We describe electron Fourier ptychography and its application to phase reconstruction of both radiation-resistant and beam-sensitive materials. We…

State-of-the-art (SoTA) models have improved the accuracy of object detection with a large margin via a FP (feature pyramid). FP is a top-down aggregation to collect semantically strong features to improve scale invariance in both two-stage…

Computer Vision and Pattern Recognition · Computer Science 2019-12-11 Ping-Yang Chen , Jun-Wei Hsieh , Chien-Yao Wang , Hong-Yuan Mark Liao , Munkhjargal Gochoo

Following the recent developement of Fourier ptychographic microscopy (FPM) in the visible range by Zheng et al. (2013), we propose an adaptation for hard x-rays. FPM employs ptychographic reconstruction to merge a series of low-resolution,…

Instrumentation and Detectors · Physics 2016-09-27 H. Simons , H. F. Poulsen , J. P. Guigay , C. Detlefs

Fourier ptychography (FP) is an enabling imaging technique that produces high-resolution complex-valued images with extended field coverages. However, when FP images a phase object with any specific spatial frequency, the captured images…

Wide dynamic range (WDR) images contain more scene details and contrast when compared to common images. However, it requires tone mapping to process the pixel values in order to display properly. The details of WDR images can diminish…

Image and Video Processing · Electrical Eng. & Systems 2021-02-02 Jie Yang , Ziyi Liu , Mengchen Lin , Svetlana Yanushkevich , Orly Yadid-Pecht

Polarized synchrotron emission from multiple Faraday depths can be separated by calculating the complex Fourier transform of the Stokes' parameters as a function of the wavelength squared, known as Faraday Synthesis. As commonly…

Instrumentation and Methods for Astrophysics · Physics 2023-04-26 Lawrence Rudnick , William D. Cotton

Recently Fourier Ptychography (FP) has attracted great attention, due to its marked effectiveness in leveraging snapshot numbers for spatial resolution in large field-of-view imaging. To acquire high signal-to-noise-ratio (SNR) images under…

Optics · Physics 2015-02-19 Liheng Bian , Jinli Suo , Guoan Zheng , KaiKai Guo , Feng Chen , Qionghai Dai

Phase retrieval is one of the most challenging processes in many interferometry techniques. To promote the phase retrieval, Xu et. al [X. Xu, Y. Wang, Y. Xu, W. Jin. 2016] proposed a method based on dual-wavelength interferometry. However,…

Instrumentation and Detectors · Physics 2018-02-14 Minmin Wang , Canlin Zhou , Shuchun Si , XiaoLei Li , Zhenkun Lei , YanJie Li

Fringe projection profilometry (FPP) is one of the most popular three-dimensional (3D) shape measurement techniques, and has becoming more prevalently adopted in intelligent manufacturing, defect detection and some other important…

Image and Video Processing · Electrical Eng. & Systems 2020-04-24 Jiaming Qian , Shijie Feng , Tianyang Tao , Yan Hu , Yixuan Li , Qian Chen , Chao Zuo

Fourier ptychography microscopy(FP) is a recently developed computational imaging approach for microscopic super-resolution imaging. By turning on each light-emitting-diode (LED) located on different position on the LED array sequentially…

Optics · Physics 2022-02-22 Delong Yang , Shaohui Zhang , Chuanjian Zheng , Guocheng Zhou , Lei Cao , Yao Hu , Qun Hao

Fourier ptychographic microscopy enables gigapixel-scale imaging, with both large field-of-view and high resolution. Using a set of low-resolution images that are recorded under varying illumination angles, the goal is to computationally…

Signal Processing · Electrical Eng. & Systems 2018-03-13 Emrah Bostan , Mahdi Soltanolkotabi , David Ren , Laura Waller

In radar systems, high resolution in the Doppler dimension is important for detecting slow-moving targets as it allows for more distinct separation between these targets and clutter, or stationary objects. However, achieving sufficient…

Computer Vision and Pattern Recognition · Computer Science 2025-05-26 Denisa Qosja , Kilian Barth , Simon Wagner

In Fringe Projection Profilometry (FPP), achieving robust and accurate 3D reconstruction with a limited number of fringe patterns remains a challenge in structured light 3D imaging. Conventional methods require a set of fringe images, but…

Computer Vision and Pattern Recognition · Computer Science 2024-02-05 Won-Hoe Kim , Bongjoong Kim , Hyung-Gun Chi , Jae-Sang Hyun

In his monograph Chebyshev and Fourier Spectral Methods, John Boyd claimed that, regarding Fourier spectral methods for solving differential equations, ``[t]he virtues of the Fast Fourier Transform will continue to improve as the relentless…

Numerical Analysis · Mathematics 2023-02-03 Craig Gross , Mark Iwen

The reconstruction of high-dimensional sparse signals is a challenging task in a wide range of applications. In order to deal with high-dimensional problems, efficient sparse fast Fourier transform algorithms are essential tools. The second…

Numerical Analysis · Mathematics 2017-11-15 Lutz Kämmerer , Daniel Potts , Toni Volkmer

Discrete Fourier Transform (DFT) is widely used in signal processing to analyze the frequencies in a discrete signal. However, DFT fails to recover the exact Fourier spectrum, when the signal contains frequencies that do not correspond to…

Data Analysis, Statistics and Probability · Physics 2015-06-15 M. Andrecut

Vertex-frequency analysis, particularly the windowed graph Fourier transform (WGFT), is a significant challenge in graph signal processing. Tight frame theories is known for its low computational complexity in signal reconstruction, while…

Signal Processing · Electrical Eng. & Systems 2024-12-31 Linbo Shang , Zhichao Zhang

Discrete Wavelet Transform (DWT) has been widely explored to enhance the performance of image superresolution (SR). Despite some DWT-based methods improving SR by capturing fine-grained frequency signals, most existing approaches neglect…

Computer Vision and Pattern Recognition · Computer Science 2025-11-05 Peng Du , Hui Li , Han Xu , Paul Barom Jeon , Dongwook Lee , Daehyun Ji , Ran Yang , Feng Zhu

For single source helical Computed Tomography (CT), both Filtered-Back Projection (FBP) and statistical iterative reconstruction have been investigated. However for dual source CT with flying focal spot (DS-FFS CT), statistical iterative…

Image and Video Processing · Electrical Eng. & Systems 2022-02-14 Xiao Wang , Robert D. MacDougall , Peng Chen , Charles A. Bouman , Simon K. Warfield