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We introduce a dual-wavelength Fourier ptychographic topography (FPT) method that extends the lambda/2 height-range limit of single-wavelength FPT. By reconstructing complex fields at two illumination wavelengths and exploiting their phase…

Microscopic fringe projection profilometry is a powerful 3D measurement technique with a theoretical measurement accuracy better than one micron provided that the measured targets can be imaged with good fringe visibility. However,…

Image and Video Processing · Electrical Eng. & Systems 2019-06-26 Yan Hu , Qian Chen , Yichao Liang , Shijie Feng , Tianyang Tao , Chao Zuo

We present a study dealing with a novel phase reconstruction method based on iterated Hilbert transform embeddings. We show results for the Stuart-Landau oscillator observed by generic observables. The benefits for reconstruction of the…

Numerical Analysis · Mathematics 2020-04-29 Erik Gengel , Arkady Pikovsky

The graph Hilbert transform (GHT) is a key tool in constructing analytic signals and extracting envelope and phase information in graph signal processing. However, its utility is limited by confinement to the graph Fourier domain, a fixed…

Signal Processing · Electrical Eng. & Systems 2025-09-23 Daxiang Li , Zhichao Zhang

The structural complexity and instability of many interference phase microscopy methods are the major obstacles toward high-precision phase measurement. In this vein, improving more efficient configurations as well as proposing new methods…

Optics · Physics 2020-01-08 Samira Ebrahimi , Masoomeh Dashtdar

Schlieren deflectometry aims at characterizing the deflections undergone by refracted incident light rays at any surface point of a transparent object. For smooth surfaces, each surface location is actually associated with a sparse…

Computer Vision and Pattern Recognition · Computer Science 2012-12-04 Prasad Sudhakar , Laurent Jacques , Xavier Dubois , Philippe Antoine , Luc Joannes

A two-step detection strategy is suggested for the precise measurement of the optical phase-shift. In the first step an unsharp, however, unbiased joint measurement of the phase and photon number is performed by heterodyning the signal…

Quantum Physics · Physics 2009-10-31 A. V. Chizhov , V. De Renzi , M. G. A. Paris

Fringe projection profilometry (FPP) has become increasingly important in dynamic 3-D shape measurement. In FPP, it is necessary to retrieve the phase of the measured object before shape profiling. However, traditional phase retrieval…

Image and Video Processing · Electrical Eng. & Systems 2020-04-22 Haotian Yu , Xiaoyu Chen , Zhao Zhang , Yi Zhang , Dongliang Zheng , Jing Han

Phase retrieval with pre-defined optical masks can provide extra constraint and thus achieve improved performance. The recent progress in optimization theory demonstrates the superiority of random masks in phase retrieval algorithms.…

Image and Video Processing · Electrical Eng. & Systems 2022-07-27 Qiuliang Ye , Yuk-Hee Chan , Michael G. Somekh , Daniel P. K. Lun

The paper presents an alternative way to classical stereocorrelation. First, 2D image processing of random patterns is described. Sub-pixel displacements are determined using phase analysis. Then distortion evaluation is presented. The…

Classical Physics · Physics 2013-11-18 Jérôme Molimard , Gaetan Boyer , Hassan Zahouani

Phase estimation, at the heart of many quantum metrology and communication schemes, can be strongly affected by noise, whose amplitude may not be known, or might be subject to drift. Here, we investigate the joint estimation of a phase…

We introduce the Divergence Phase Index (DPI), a novel framework for quantifying phase differences in one and multidimensional signals, grounded in harmonic analysis via the Riesz transform. Based on classical Hilbert Transform phase…

Machine Learning · Statistics 2025-10-07 Magaly Catanzariti , Hugo Aimar , Diego M. Mateos

This paper investigates experimental means of measuring the transmission matrix (TM) of a highly scattering medium, with the simplest optical setup. Spatial light modulation is performed by a digital micromirror device (DMD), allowing high…

We propose an innovative demodulation scheme for coherent detectors used in cosmic microwave background polarization experiments. Removal of non-white noise, e.g., narrow-band noise, in detectors is one of the key requirements for the…

Instrumentation and Methods for Astrophysics · Physics 2012-05-22 K. Ishidoshiro , Y. Chinone , M. Hasegawa , M. Hazumi , M. Nagai , O. Tajima

Fluorescent imaging plays a critical role in a myriad of scientific endeavors, particularly in the biological sciences. Three-dimensional imaging of fluorescent intensity often requires serial data acquisition, that is voxel-by-voxel…

Optics · Physics 2015-10-27 Jeffrey J. Field , David G. Winters , Randy A. Bartels

We have presented a new and alternative algorithm for noise reduction using the methods of discrete wavelet transform and numerical differentiation of the data. In our method the threshold for reducing noise comes out automatically. The…

This article presents a new optical measurement method employing a HSI (Hue, Saturation and Intensity) colour model to form trapezoidal structured patterns for morphology reconstruction of a measured object at a high speed. Profilometry on…

Optics · Physics 2015-05-19 L C Chen , X L Nguyen , Y S Shu

This paper presents a two-step approach for narrowband source localization within reverberant rooms. The first step involves dereverberation by modeling the homogeneous component of the sound field by an equivalent decomposition of…

Audio and Speech Processing · Electrical Eng. & Systems 2023-09-26 Wei-Ting Lai , Lachlan Birnie , Thushara Abhayapala , Amy Bastine , Shaoheng Xu , Prasanga Samarasinghe

Fraunhofer diffraction is a well-known phenomenon achieved with most wavelength even without lens. A single-shot intensity measurement of diffraction is generally considered inadequate to reconstruct the original light field, because the…

Image and Video Processing · Electrical Eng. & Systems 2019-12-04 An-Dong Xiong , Xiao-Peng Jin , Wen-Kai Yu , Qing Zhao

Accurate phase estimation plays a pivotal role in quantum metrology, yet its precision is significantly affected by noise, particularly phase-diffusive noise caused by phase drift. To address this challenge, the joint estimation of phase…

Quantum Physics · Physics 2026-03-17 Ben Wang , Minghao Mi , Huangqiuchen Wang , Qian Xie , Lijian Zhang