Concept
Phase retrieval
Related publications (34)
Phase Retrieval: From Computational Imaging to Machine Learning: A tutorial
Michaël Unser, Thanh-An Michel Pham, Jonathan Yuelin Dong
Phase retrieval consists in the recovery of a complex-valued signal from intensity-only measurements. As it pervades a broad variety of applications, many researchers have striven to develop phase-retrieval algorithms. Classical approaches involve techniqu ...
2023Learning-based techniques for lensless reconstruction
In this internship, I explore different optimization algorithms for lensless imaging. Lensless imaging is a new imaging technique that replaces the lens of a camera with a diffuser mask. This allows for simpler and cheaper camera hardware. However, the rec ...
2023Phase Reconstruction of Low-Energy Electron Holograms of Individual Proteins
Klaus Kern, Stephan Rauschenbach, Sven Alexander Szilagyi, Hannah Julia Ochner
Low-energy electron holography (LEEH) is one of the few techniques capable of imaging large and complex three-dimensional molecules, such as proteins, on the single molecule level at subnanometer resolution. During the imaging process, the structural infor ...
AMER CHEMICAL SOC2022Amplitude and phase reconstruction for Low-Energy Electron Holography of individual proteins
Single-molecule imaging methods are of importance in structural biology, and specifically in the imaging of proteins, since they can elucidate conformational variability and structural changes that might be lost in imaging methods relying on averaging proc ...
EPFL2022Stochasticity helps to navigate rough landscapes: comparing gradient-descent-based algorithms in the phase retrieval problem
Lenka Zdeborová, Francesca Mignacco
In this paper we investigate how gradient-based algorithms such as gradient descent (GD), (multi-pass) stochastic GD, its persistent variant, and the Langevin algorithm navigate non-convex loss-landscapes and which of them is able to reach the best general ...
IOP PUBLISHING LTD20213D nanometrology of transparent objects by phase calibration of a basic bright-field microscope for multiple illumination apertures
Martinus Gijs, Daniel Migliozzi, Bingying Zhao
Optical retrieval of the structure of transparent objects at the nanoscale requires adapted techniques capable of probing their interaction with light. Here, we considered a method based on calibration of the defocusing with partially coherent illumination ...
2020Monitoring Spontaneous Charge-Density Fluctuations by Single-Molecule Diffraction of Quantum Light
Homodyne X-ray diffraction signals produced by classical light and classical detectors are given by the modulus square of the charge density in momentum space vertical bar sigma(q)vertical bar(2), missing its phase, which is required in order to invert the ...
2019Deep Feature Factorization For Content-Based Image Retrieval And Localization
State of the art content-based image retrieval algorithms owe their excellent performance to the rich semantics encoded in the deep activations of a convolutional neural network. The difference between these algorithms lies mostly in how activations are co ...
IEEE2019Proximity Operators for Phase Retrieval
Michaël Unser, Frédéric Courbin, Ferréol Arnaud Marie Soulez
We present a new formulation of a family of proximity operators that generalize the projector step for phase retrieval. These proximity operators for noisy intensity measurements can replace the classical "noise-free" projection in any projection-based alg ...
OSA2016Spline based iterative phase retrieval algorithm for X-ray differential phase contrast radiography
Michaël Unser, Masih Nilchian, Marco Stampanoni
Differential phase contrast imaging using grating interferometer is a promising alternative to conventional X-ray radiographic methods. It provides the absorption, differential phase and scattering information of the underlying sample simultaneously. Phase ...
Optical Soc Amer2015