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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

In X-ray phase contrast imaging, phase retrieval from intensity measurements is the key for further quantitative analysis and tomographic reconstructions. In this letter, we present a single-shot approach for quantitative phase retrieval in…

Instrumentation and Detectors · Physics 2016-10-03 Wang Zhili , Liu Dalin

We propose Fourier transform (FT) method for processing images of extensive air showers (EAS) detected by imaging atmospheric Cherenkov telescopes (IACT) used in the very high energy (VHE) gamma-ray astronomy. The method is based on the…

Astrophysics · Physics 2009-11-10 A. Atoyan , J. Patera , V. Sahakian , A. Akpherjanian

Transform image processing methods are methods that work in domains of image transforms, such as Discrete Fourier, Discrete Cosine, Wavelet and alike. They are the basic tool in image compression, in image restoration, in image re-sampling…

Computer Vision and Pattern Recognition · Computer Science 2014-08-28 Leonid Yaroslavsky

Background: Tumour budding is an independent predictor of metastasis and prognosis in colorectal cancer and is a vital part of the pathology specification report. In a conventional pathological section observation process, pathologists have…

Medical Physics · Physics 2025-03-21 Yiyan Su , Ruiqing Sun , Yajing Wang , Yanfeng xi , Shaohui Zhang

Modern high-resolution microscopes, such as the scanning tunneling microscope, are commonly used to study specimens that have dense and aperiodic spatial structure. Extracting meaningful information from images obtained from such…

Computational Physics · Physics 2018-08-28 Sky C. Cheung , John Y. Shin , Yenson Lau , Zhengyu Chen , Ju Sun , Yuqian Zhang , John N. Wright , Abhay N. Pasupathy

A new multifocus image fusion approach is presented in this paper. First the contourlet transform is used to decompose the source images into different components. Then, some salient features are extracted from components. In order to…

Computer Vision and Pattern Recognition · Computer Science 2017-09-28 Fatemeh Vakili Moghadam , Hamid Reza Shahdoosti

Combining images with different exposure settings are of prime importance in the field of computational photography. Both transform domain approach and filtering based approaches are possible for fusing multiple exposure images, to obtain…

Image and Video Processing · Electrical Eng. & Systems 2021-10-04 Vivek Ramakarishnan , Dnyaneshwar Jageshwar Pete

Phase-sensitive coherent imaging exploits changes in the phases of backscattered light to observe tiny alterations of scattering structures or variations of the refractive index. But moving scatterers or a fluctuating refractive index…

In this paper, we describe the principle of a multi-aperture interferometer that uses a phase-shifting technique and is suitable for quick, snapshot imaging of astrophysical objects at extreme angular resolution through Fourier inversion. A…

Optics · Physics 2015-05-28 Francois Henault

Coherent diffractive imaging (CDI) provides new opportunities for high resolution X-ray imaging with simultaneous amplitude and phase contrast. Extensions to CDI broaden the scope of the technique for use in a wide variety of experimental…

Optics · Physics 2016-01-20 Matthew H. Seaberg , Alexandre d'Aspremont , Joshua J. Turner

In this paper, we study the mathematical imaging problem of diffraction tomography (DT), which is an inverse scattering technique used to find material properties of an object by illuminating it with probing waves and recording the…

Numerical Analysis · Mathematics 2023-05-16 Florian Faucher , Clemens Kirisits , Michael Quellmalz , Otmar Scherzer , Eric Setterqvist

This study describes a new approach for material decomposition in x-ray imaging, utilising phase contrast to both increase sensitivity to weakly-attenuating samples and to act as a complementary measurement to attenuation, therefore…

The use of Fourier methods in wave-front reconstruction can significantly reduce the computation time for large telescopes with a high number of degrees of freedom. However, Fourier algorithms for discrete data require a rectangular data…

Instrumentation and Methods for Astrophysics · Physics 2017-06-07 Charlotte Z. Bond , Carlos M. Correia , Jean-François Sauvage , Benoit Neichel , Thierry Fusco

Fourier ptychography microscopy (FPM), sharing its roots with synthetic aperture technique and phase retrieval method, is a recently developed computational microscopic super-resolution technique. By turning on the light-emitting diode…

Optics · Physics 2021-05-07 G. Zhou , S. Zhang , C. Zheng , T. Li , Y. Hu , Q. Hao

X-ray phase-contrast imaging has experienced rapid development over the last few decades, and in this technology, the phase modulation strategy of phase-stepping is used most widely to measure the sample's phase signal. However, because of…

Medical Physics · Physics 2017-12-06 Faiz Wali , Shenghao Wang , Huajie Han , Kun Gao , Zhao Wu , Peiping Zhu , Yangchao Tiana

Phase-contrast and dark-field imaging are relatively new X-ray imaging modalities that provide additional information to conventional attenuation-based imaging. However, this new information comes at the price of a more complex acquisition…

We consider a particular approach to the regularization of the inverse problem of computerized tomography. This approach is based on notions pertaining to Fourier synthesis. It refines previous contributions, in which the preprocessing of…

Optimization and Control · Mathematics 2014-01-30 Pierre Maréchal , Abdelhadi Elasmai

The cross section of X-ray phase contrast caused by these low-Z elements is greatly bigger than the absorption. Therefore, in the field of X-ray imaging, the phase shift information can offer better imaging contrast. In this paper, we…

Instrumentation and Detectors · Physics 2018-08-15 Rongqi Sun , Lian Chen , Houbing Lu , Feng Li , Ge Jin

A special algorithm for the Fourier-transform Ghost Imaging (GI) scheme is discussed based on the Compressive Sampling (CS) theory. Though developed mostly in real space, CS algorithm could also be used for the Fourier spectrum…

Quantum Physics · Physics 2009-11-23 Hui Wang , Shensheng Han
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