Publications de Michaël Unser

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We propose a new spatio-temporal elastic registration algorithm for motion reconstruction from a series of images. The specific application is to estimate displacement fields from two-dimensional ultrasound sequences of the heart. The basic idea is to find ...

The emergence of deep-learning-based methods to solve image-reconstruction problems has enabled a significant increase in quality. Unfortunately, these new methods often lack reliability and explainability, and there is a growing interest to address these ...

We consider the problem of estimating a fractional Brownian motion known only from its noisy samples at the integers. We show that the optimal estimator can be expressed using a digital Wiener-like filter followed by a simple time-variant correction accoun ...

A central challenge in scanning transmission electron microscopy (STEM) is to reduce the electron radiation dosage required for accurate imaging of 3D biological nano-structures. Methods that permit tomographic reconstruction from a reduced number of STEM ...

We consider the task of estimating an operator from sampled data. The operator, which is described by a rational transfer function, is applied to continuous-time white noise and the resulting continuous-time process is sampled uniformly. The main question ...

One very influential method for texture synthesis is based on the steerable pyramid by alternately imposing marginal statistics on the image and the pyramid's subbands. In this work, we investigate two extensions to this framework. First, we exploit the st ...

This is the second in a series of three columns summarizing the "Trends" expert sessions organized by the Signal Processing Society Technical Committees during ICASSP 2011 in Prague, Czech Republic. Readers have an opportunity to access these Trends sessio ...

Traditional snakes, or active contours, are planar parametric curves. Their parameters are determined by optimizing the weighted sum of three energy terms: one depending on the data (typically on the integral of its gradient under the curve, or on its inte ...

Real-world data such as multimedia, biomedical, and telecommunication signals are formed of specific structures. However, these structures only determine some general properties of the data while the unknown or unpredictable parts are assumed to be random. ...

One disadvantage of all fluorescence imaging modalities is a poor axial resolution. To overcome this issue, we propose a novel approach to reconstruct fluorescence volumes with isotropic high resolution, from images of particle replicates observed at multi ...

We present a texture-driven parametric snake for semi-automatic segmentation of a single and closed structure in an image. We propose a new energy functional that combines intensity and texture information. The two types of image information are balanced u ...

With the widespread uptake of two-dimensional (2D) and three-dimensional (3D) single-molecule localization microscopy (SMLM), a large set of different data analysis packages have been developed to generate super-resolution images. In a large community effo ...

We propose a new parametric 3D snake with cylindrical topology. Its construction is based on interpolatory basis functions which facilitates user-interaction because the control points of the snake directly lie on the surface of the deformable cylinder. We ...

The combination of wavelength multiplexing and spectral interferometry allows for the encoding of multidimensional information and its transmission over a mono-dimensional channel; for example, measurements of a surface's topography acquired through a mono ...

Starting from any two given multiresolution analyses of

L _{ 2 }

\{V ^{ 1 } _{ j } \} _{ j \in Z }

, and

\{V ^{ 2 } _{ j } \} _{ j \in Z }

, we construct biorthogonal wavelet bases that are associated with this chosen pair of multiresolutions. Thus, our construction method takes a point of view opposite to the one of Cohen-Daubechies-Feauveau (CDF), which starts from a well-chosen pair of biorthogonal discrete filters. In our construction, the necessary and sufficient condition is the nonperpe

本稿では, 2つの異なる関数基底を用いて信号を補間する手法として一般化区分的線形補間法を提案し, こうした関数系の信号処理・画像処理における有用性を検証した結果について報告する。提案する関数系は, 線形近似と同様に近似オーダー(approximation order)が2であり, 階段関数や折れ線を正確に再構成できる。関数基底は2つの実パラメータ τ と α によって特徴付けられる。パラメータ τ は関数基底の座標に対応するシフトパラメータであり, もう一方のパラメータaは関数の非対称性をあらわすパラメータである。これらのパラメータを変化させることで, 入力信号・画像に関係なく, 近似精度を向上させ最適化を図ることが可能となることを示す。この補間手法では, 2つのパラメータを, τ=0.21, α=1 と設定することで, シフト線形補間 (shifted-linear interpolation) を再現することができる。ここでは, このパラメータの組み合わせ以外に, τ=0.21, α=0.58 と設定した場合に, シフト線形補間と同様の精度で信号の補間を行うことができることに注⽬する。シフト線形補間

We present a new method for the atlas-free brain segmentation of proton-density-like 3D MRI images. We show how steerable filters can be efficiently combined with parametric spline surfaces to produce a fast and robust 3D brain segmentation algorithm. The ...

Within a deterministic framework, it is well known that n-term wavelet approximation rates of functions can be deduced from their Besov regularity. We use this principle to determine approximation rates for symmetric-α-stable (SαS) stochastic processes. Fi ...

In this paper, we discuss the sampling problem without a condition that was assumed in conventional sampling theorems. This means that we cannot perfectly reconstruct all functions in the reconstruction space. The perfect reconstruction is possible only fo ...

Michaël Unser

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Spatio-Temporal Nonrigid Registration for Ultrasound Cardiac Motion Estimation

A Neural-Network-Based Convex Regularizer for Inverse Problems

Optimal Interpolation of Fractional Brownian Motion Given Its Noisy Samples

Compressed sensing for STEM tomography

Identification of Rational Transfer Functions from Sampled Data

Pyramid-Based Texture Synthesis Using Local Orientation and Multidimensional Histogram Matching

Trends in Bioimaging and Signal Processing

The Snakuscule

Stochastic Models and Techniques for Sparse Signals

Reconstruction From Multiple Poses in Fluorescence Imaging: Proof of Concept

Effect of Ageing on Elastin Functionality in Human Cerebral Arteries

Texture-driven parametric snakes for semi-automatic image segmentation

Super-resolution fight club: assessment of 2D and 3D single-molecule localization microscopy software

New Parametric 3D Snake for Medical Segmentation of Structures with Cylindrical Topology

Continuous Wavelet Transform Ridge Extraction for Spectral Interferometry Imaging

Construction of Biorthogonal Wavelets Starting from Any Two Multiresolutions

スプライン関数とそのディジタル信号処理・画像処理への応用に関する研究

Atlas-Free Brain Segmentation in 3D Proton-Density-Like MRI Images

Compressibility of Symmetric-α-Stable Processes

An Extension of Oblique Projection Sampling Theorem