Optical diffraction tomography (ODT) can be described using the scattering process through an inhomogeneous media. An inherent nonlinearity exists relating the scattering medium and the scattered field due to multiple scattering. Multiple scattering is oft ...

SPIE-INT SOC OPTICAL ENGINEERING2018

Region Of Interest X-Ray Computed Tomography Via Corrected Back Projection

Michaël Unser, Laura Vilaclara, Michael Thompson McCann

We present a new method for region of interest (ROI) reconstruction from high-resolution, nontruncated data in parallel-ray X-ray computed tomography (CT). Many of the approaches to ROI CT reconstruction in the literature rely on a costly forward projectio ...

IEEE2018

Fast multiscale reconstruction for Cryo-EM

Michaël Unser, Masih Nilchian, Laurène Donati

We present a multiscale reconstruction framework for single-particle analysis (SPA). The representation of three-dimensional (3D) objects with scaled basis functions permits the reconstruction of volumes at any desired scale in the real-space. This multisc ...

Elsevier2018

Landmark-Based Shape Encoding and Sparse-Dictionary Learning in the Continuous Domain

Michaël Unser, Daniel Andreas Schmitter

We provide a generic framework to learn shape dictionaries of landmark-based curves that are defined in the continuous domain. We first present an unbiased alignment method that involves the construction of a mean shape as well as training sets whose eleme ...

2018

3D Bpconvnet To Reconstruct Parallel Mri

Michaël Unser, Kyong Hwan Jin

In recent years, compressed sensing techniques have been applied to the reconstruction of parallel magnetic resonance (MR) images. Particularly for 3D MR signal, it is crucial to acquire fewer samples to reduce the distortions caused by long-time acquisiti ...

IEEE2018

Periodic Splines and Gaussian Processes for the Resolution of Linear Inverse Problems

Michaël Unser, Julien René Pierre Fageot, Anaïs Laure Marie-Thérèse Badoual

This paper deals with the resolution of inverse problems in a periodic setting or, in other terms, the reconstruction of periodic continuous-domain signals from their noisy measurements. We focus on two reconstruction paradigms: variational and statistical ...

2018

Phaseless Diffraction Tomography With Regularized Beam Propagation

Michaël Unser, Alexandre Goy, Demetri Psaltis, Thanh-An Michel Pham, Ferréol Arnaud Marie Soulez, Joowon Lim, Emmanuel Emilien Louis Soubies

In recent years, researchers have obtained impressive reconstructions of the refractive index (RI) of biological objects through the combined use of advanced physics (nonlinear forward model) and regularization. Here, we propose an adaptation of these tech ...

IEEE2018

Optical Tomography Based On A Nonlinear Model That Handles Multiple Scattering

Michaël Unser, Alexandre Goy, Ulugbek Kamilov, Demetri Psaltis, Joowon Lim

Learning Tomography (LT) is a nonlinear optimization algorithm for computationally imaging three-dimensional (3D) distribution of the refractive index in semi-transparent samples. Since the energy function in LT is generally non-convex, the solution it obt ...

Ieee2017

System and Method for Defining Watertight and Locally Refinable Surfaces with Interpolatory Control Points

Michaël Unser, Daniel Andreas Schmitter, Masih Nilchian

A method for creating a watertight boundary between two graphical elements including the steps of displaying a first surface having a first shape and a second surface having a second shape on the display, an open space existing between the first surface an ...

2017

High-Quality Parallel-Ray x-Ray CT Back Projection Using Optimized Interpolation

Michaël Unser, Michael Thompson McCann

We propose a new, cost-efficient method for computing back projections in parallel-ray X-ray CT. Forward and back projections are the basis of almost all X-ray CT reconstruction methods, but computing these accurately is costly. In the special case of para ...

2017

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