Publications associées à Moiré (physique)

Analysis system and method for analysing the movement of a portion of the body and/or of a human prosthesis

Silvestro Micera, Andrea Crema, Fiorenzo Artoni

An analysis method (200) for analysing the pressure exerted by a portion of the body and/or of a human prosthesis comprises the following steps: sampling data generated by the portion of the body and/or the human prosthesis during a threshold calibration p ...

2021

Level-line moirés by superposition of cylindrical microlens gratings

Jürgen Brugger, Roger Hersch, Thomas Walger, Valentin Flauraud, Théophane Besson

Two superposed layers of transparent cylindrical lenslet gratings create classical moiré fringes when illuminated from behind. We rely on this observation to conceive special devices made of superposed lenslet gratings that produce compelling beating shape ...

2020

Moiré effects produced by superpositions of micro-lens arrays

Thomas Walger

Moiré effects result from the superimposition of repetitive structures. The beauty of these moirés comes from the fact that macroscopic shapes seem to appear from the superposition of layers containing microscopic patterns. In addition, the moirés are dyna ...

EPFL2020

Compressed sensing with signal averaging for improved sensitivity and motion artifact reduction in fluorine-19 MRI

Tobias Kober, Tom Hilbert, Jérôme Yerly, Ruud van Heeswijk, Elena Najdenovska

Fluorine-19 (F-19) MRI of injected perfluorocarbon emulsions (PFCs) allows for the non-invasive quantification of inflammation and cell tracking, but suffers from a low signal-to-noise ratio and extended scan time. To address this limitation, we tested the ...

WILEY2020

Holographic reconstruction of interlayer distance of bilayer two-dimensional crystal samples from their convergent beam electron diffraction patterns

Tatiana Latychevskaia

Convergent beam electron diffraction (CBED) patterns of twisted bilayer samples exhibit interference patterns in their CBED spots. Such interference patterns can be treated as off-axis holograms and the phase of the scattered waves, and hence the interlaye ...

2020

Near-field phase profile and far-field contrast modulation for micro-lens arrays at the refraction limit

Toralf Scharf, Maryam Yousefi, Daniel Necesal

We investigate the far-field pattern generation for a micro-lens array (MLA) illuminated under different conditions. Plane wave and Gaussian beam illumination are considered for an MLA with a small diameter of 27 microns and 30 microns period. At these dim ...

2020

Accelerated MP2RAGE imaging using Cartesian phyllotaxis readout and compressed sensing reconstruction

Jean-Philippe Thiran, Tobias Kober, Tom Hilbert, Reto Meuli

Purpose MP2RAGE T-1-weighted imaging has been shown to be beneficial for various applications, mainly because of its good grey-white matter contrast, its B-1-robustness and ability to derive T(1)maps. Even using parallel imaging, the method requires long a ...

WILEY2020

Angular Color Prediction Model for Anisotropic Halftone Prints on a Metallic Substrate

Roger Hersch, Lin Yang, Petar Pjanic

Under specular reflection, non-isotropic halftones such as line halftones printed on an ink-receiving plastic layer superposed with a metallic layer change their colors upon in-plane rotation of the print. This color change is due to the orientation-depend ...

I S & T-SOC IMAGING SCIENCE TECHNOLOGY2019

Graph-based image representation learning

Renata Khasanova

Though deep learning (DL) algorithms are very powerful for image processing tasks, they generally require a lot of data to reach their full potential. Furthermore, there is no straightforward way to impose various properties, given by the prior knowledge a ...

EPFL2019

Generalized Skipgrams for Pattern Discovery in Polyphonic Streams

Martin Alois Rohrmeier, Markus Franz Josef Neuwirth, Christoph Finkensiep

The discovery of patterns using a minimal set of assumptions constitutes a central challenge in the modeling of polyphonic music and complex streams in general. Skipgrams have been found to be a powerful model for capturing semi-local dependencies in seque ...

2018

Hardware And Software For Reproducible Research In Audio Array Signal Processing

Paul Hurley, Eric Bezzam, Sepand Kashani, René Beuchat, Matthieu Martin Jean-André Simeoni, Robin Scheibler, Hanjie Pan, Corentin Ferry, Basile Gérard Pierre Bruneau

In our demo, we present two hardware platforms for prototyping audio array signal processing. Pyramic is a 48-channel microphone array fitted on an FPGA and Compact Six is a portable microphone array with six microphones, closer to the technical constraint ...

Ieee2017

Color Changing Prints on a Metallic Substrate

Petar Pjanic

Printing on a flat metallic substrate has gained popularity in recent years. The reflection of light on a specularly reflecting metallic substrate differs strongly from the reflection of light on a diffusely reflecting medium such as paper. Direct prints o ...

EPFL2016

Image Reconstruction in K-Space from MR Data Encoded with Ambiguous Gradient Fields

Daniel Gallichan

PurposeIn this work, the limits of image reconstruction in k-space are explored when non-bijective gradient fields are used for spatial encoding. TheoryThe image space analogy between parallel imaging and imaging with non-bijective encoding fields is parti ...

Wiley-Blackwell2015

Real-Time Free Viewpoint Synthesis Using Three-Camera Disparity Estimation Hardware

Alexandre Schmid, Jonathan Sylvain Masur, Yusuf Leblebici, Abdulkadir Akin, Raffaele Capoccia, Jonathan Emmanuel D Narinx

The recent development of high quality free viewpoint synthesis algorithms and their implementations allows to realize glasses-free 3D perception. Although many algorithms are developed on this domain, the real-time hardware realization of a free viewpoint ...

2015

Beating Shapes Relying on Moire Level Lines

Roger Hersch, Sylvain Chosson

We consider the problem of obtaining a recognizable shape as superposition moire of two line gratings. The method we propose generates moire lines located between the shape foreground and background centers and the shape boundaries. Upon relative displacem ...

Association for Computing Machinery2014

Measurement of in-plane and out-of-plane displacements and strains using digital holographic moiré

Pramod Rastogi, Sai Siva Gorthi, Rishikesh Dilip Kulkarni

The paper proposes a non-destructive method for simultaneous measurement of in-plane and out-of-plane displacements and strains undergone by a deformed specimen from a single moire fringe pattern obtained on the specimen in a dual beam digital holographic ...

Taylor & Francis2014

Simultaneous measurement of in-plane and out-of-plane displacements using pseudo-Wigner-Hough transform

Pramod Rastogi, Rishikesh Dilip Kulkarni

A new method based on pseudo-Wigner-Hough transform is proposed for the simultaneous measurement of the in-plane and out-of-plane displacements using digital holographic moire. Multiple interference phases corresponding to the in-plane and out-of-plane dis ...

Optical Society of America2014

Improved temporal resolution for functional studies with reduced number of segments with three-dimensional echo planar imaging

Rolf Gruetter, Tobias Kober, Wietske Van der Zwaag, José Pedro Rebelo Ferreira Marques, Mayur Narsude

PURPOSE: To introduce a new k-space traversal strategy for segmented three-dimensional echo planar imaging (3D EPI) that encodes two partitions per radiofrequency excitation, effectively reducing the number excitations used to acquire a 3D EPI dataset by h ...

Wiley-Blackwell2014

Mechanical form-finding of timber fabric structures

Seyed Sina Nabaei

How about fastening a knot? not with ropes... but with timber panels. Timber Fabric Structures (TFS) originate from such an inspiration. An architectural reinterpretation of fabric techniques (mainly braiding) using building scale timber panels to design ...

EPFL2014

High-resolution 1D moirés as counterfeit security features

Jürgen Brugger, Roger Hersch, Katrin Sidler Arnet, Victor Javier Cadarso Busto, Sylvain Chosson

A moire is an interference pattern that appears when two different periodic structures are overlaid. The image created is extremely sensitive to small variations in the original layers and is thus very interesting for anti-counterfeit protection. We presen ...

Nature Publishing Group2013