English
Related papers

Related papers: Phase offset method of ptychographic contrast reve…

200 papers

Single-shot volumetric fluorescence (SVF) imaging offers a significant advantage over traditional imaging methods that require scanning across multiple axial planes as it can capture biological processes with high temporal resolution. The…

We propose a single-snapshot depth-from-defocus (DFD) reconstruction method for coded-aperture imaging that replaces hand-crafted priors with a learned diffusion prior used purely as regularization. Our optimization framework enforces…

Computer Vision and Pattern Recognition · Computer Science 2025-09-29 Hodaka Kawachi , Jose Reinaldo Cunha Santos A. V. Silva Neto , Yasushi Yagi , Hajime Nagahara , Tomoya Nakamura

The treatment found on most general optics textbooks related to the phase contrast technique imposes limitations on the filter phase and object phase variations in order to mathematically explain it in a simple manner. We consider that this…

Forward and backward scattering provide complementary volumetric and interfacial information, yet conventional three-dimensional (3D) imaging typically accesses only one. In this Letter, we present a substrate-enhanced diffraction…

Optics · Physics 2026-03-05 Tongyu Li , Yi Shen , Dashan Dong , Danchen Jia , Jianpeng Ao , Ji-Xin Cheng , Lei Tian

We propose SparseContrast, a new framework that merges dynamic sparse attention with contrastive learning for medical imaging, with a focus on chest X-ray disease detection in low-data settings. Traditional contrastive learning methods rely…

Computer Vision and Pattern Recognition · Computer Science 2026-05-05 Paarth Prasad , Ruchika Malhotra

Ptychography, a form of Coherent Diffractive Imaging, is used with short wavelengths (e.g. X-rays, electron beams) to achieve high-resolution image reconstructions. One of the limiting factors for the reconstruction quality is the accurate…

Image and Video Processing · Electrical Eng. & Systems 2018-04-02 P. Dwivedi , A. P. Konijnenberg , S. F. Pereira , H. P. Urbach

The typical contrastive self-supervised algorithm uses a similarity measure in latent space as the supervision signal by contrasting positive and negative images directly or indirectly. Although the utility of self-supervised algorithms has…

Computer Vision and Pattern Recognition · Computer Science 2021-01-14 David Torpey , Richard Klein

Point-spread function (PSF) estimation in spatially undersampled images is challenging because large pixels average fine-scale spatial information. This is problematic when fine-resolution details are necessary, as in optimal photometry…

Instrumentation and Methods for Astrophysics · Physics 2021-02-03 Teresa Symons , Michael Zemcov , James Bock , Yun-Ting Cheng , Brendan Crill , Christopher Hirata , Stephanie Venuto

Phase contrast techniques, such as differential interference contrast (DIC) microscopy, are widely used to provide morphological images of unstained biological samples. The trans-illumination geometry required for these techniques has…

Optics · Physics 2015-03-13 Tim N. Ford , Kengyeh K. Chu , Jerome Mertz

Phase distortions, or aberrations, can negatively influence the performance of an optical imaging system. Through the use of position-momentum entangled photons, we nonlocally correct for aberrations in one photon's optical path by…

In imaging modalities recording diffraction data, the original image can be reconstructed assuming known phases. When phases are unknown, oversampling and a constraint on the support region in the original object can be used to solve a…

Signal Processing · Electrical Eng. & Systems 2018-10-17 Alberto Pietrini , Carl Nettelblad

A new method recovers the phase difference of interfering wavefronts from a pattern of interference fringes, avoiding the phase discontinuity problem. The method relies on the numerical solution of one-dimensional first-order ordinary…

Optics · Physics 2024-08-01 V. Berejnov , B. Y. Rubinstein

Weakly supervised semantic segmentation (WSSS) methods using class labels often rely on class activation maps (CAMs) to localize objects. However, traditional CAM-based methods struggle with partial activations and imprecise object…

Computer Vision and Pattern Recognition · Computer Science 2025-07-01 Dewen Zeng , Xinrong Hu , Yu-Jen Chen , Yawen Wu , Xiaowei Xu , Yiyu Shi

This paper is concerned with uniqueness, phase retrieval and shape reconstruction methods for solving inverse electromagnetic source scattering problems with multi-frequency sparse phased or phaseless far field data. With the phased data,…

Analysis of PDEs · Mathematics 2019-06-07 Xia Ji , Xiaodong Liu

We report on the realization of an optical phase noise cancellation technique by passively embedding the optical phase information into a radio frequency (RF) signal and shifting the optical frequency with the amount of phase noise…

Instrumentation and Detectors · Physics 2020-07-30 Liang Hu , Xueyang Tian , Guiling Wu , Jianping Chen

The phase of a single-mode field can be measured in a single-shot measurement by interfering the field with an effectively classical local oscillator of known phase. The standard technique is to have the local oscillator detuned from the…

Quantum Physics · Physics 2009-10-30 H. M. Wiseman

An improved phase retrieval method based Hilbert transform is introduced to quantitatively calculate the phase distribution from distorted fringe pattern. Also phase measurement deflectomety are widely used in specular type samples. The…

Instrumentation and Detectors · Physics 2016-09-21 Silin Na , Sanghoon Shin , Younghun Yu

In this paper, we address the task of aberration-aware depth-from-defocus (DfD), which takes account of spatially variant point spread functions (PSFs) of a real camera. To effectively obtain the spatially variant PSFs of a real camera…

Computer Vision and Pattern Recognition · Computer Science 2024-02-29 Zhuofeng Wu , Yusuke Monno , Masatoshi Okutomi

Natural signals and images are well-known to be approximately sparse in transform domains such as Wavelets and DCT. This property has been heavily exploited in various applications in image processing and medical imaging. Compressed sensing…

Machine Learning · Computer Science 2015-10-26 Saiprasad Ravishankar , Yoram Bresler

The optics of any camera degrades the sharpness of photographs, which is a key visual quality criterion. This degradation is characterized by the point-spread function (PSF), which depends on the wavelengths of light and is variable across…

Image and Video Processing · Electrical Eng. & Systems 2022-08-02 Thomas Eboli , Jean-Michel Morel , Gabriele Facciolo