Publications de Ricard Delgado Gonzalo

FlyLimbTracker: An Active Contour Based Approach for Leg Segment Tracking in Unmarked, Freely Behaving Drosophila

Michaël Unser, Virginie Sophie Uhlmann, Ricard Delgado Gonzalo

Understanding the biological underpinnings of movement and action requires the development of tools for quantitative measurements of animal behavior. Drosophila melanogaster provides an ideal model for developing such tools: the fly has unparalleled geneti ...

2017

A Family of Smooth and Interpolatory Basis Functions for Parametric Curve and Surface Representation

Michaël Unser, Daniel Andreas Schmitter, Ricard Delgado Gonzalo

Interpolatory basis functions are helpful to specify parametric curves or surfaces that can be modified by simple user-interaction. Their main advantage is a characterization of the object by a set of control points that lie on the shape itself (i.e., curv ...

2016

User-Friendly Image-Based Segmentation and Analysis of Chromosomes

Florian Maria Wurm, Michaël Unser, Lucia Baldi Unser, Virginie Sophie Uhlmann, Ricard Delgado Gonzalo

We designed two efficient and user-friendly tools for the segmentation and analysis of images containing chromosomes or, more generally, rod-shaped elements that are spread on microscopic slides. The segmentation tool allows to automatically extract the pr ...

IEEE2016

Trigonometric Interpolation Kernel to Construct Deformable Shapes for User-Interactive Applications

Michaël Unser, Daniel Andreas Schmitter, Ricard Delgado Gonzalo

We present a new trigonometric basis function that is capable of perfectly reproducing circles, spheres and ellipsoids while at the same time being interpolatory. Such basis functions have the advantage that they allow to construct shapes through a sequenc ...

IEEE Institute of Electrical and Electronics Engineers2015

Efficient Shape Priors for Spline-Based Snakes

Michaël Unser, Daniel Andreas Schmitter, Virginie Sophie Uhlmann, Ricard Delgado Gonzalo

Parametric active contours are an attractive approach for image segmentation, thanks to their computational efficiency. They are driven by application-dependent energies that reflect the prior knowledge on the object to be segmented. We propose an energy i ...

2015

Snakes on a Plane [A perfect snap for bioimage analysis]

Michaël Unser, Daniel Andreas Schmitter, Virginie Sophie Uhlmann, Ricard Delgado Gonzalo

2015

Anillin Regulates Cell-Cell Junction Integrity by Organizing Junctional Accumulation of Rho-GTP and Actomyosin

Ricard Delgado Gonzalo

Anillin is a scaffolding protein that organizes and stabilizes actomyosin contractile rings and was previously thought to function primarily in cytokinesis [1-10]. Using Xenopus laevis embryos as a model system to examine Anillin's role in the intact verte ...

Cell Press2014

Snakes with Tangent-Based Control and Energies for Bioimage Analysis

Michaël Unser, Virginie Sophie Uhlmann, Ricard Delgado Gonzalo

We propose a novel active contour for the analysis of filament-like structures and boundaries—features that traditional snakes based on closed curves have difficulties to delineate. Our method relies on a parametric representation of an open curve involvin ...

IEEE2014

Exponential Hermite Splines For The Analysis Of Biomedical Images

Michaël Unser, Virginie Sophie Uhlmann, Ricard Delgado Gonzalo

We present a new exponential B-spline basis that enables the construction of active contours for the analysis of biomedical images. Our functions generalize the well-known polynomial Hermite B-splines and provide us with a direct control over the tangents ...

Ieee2014

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

Michaël Unser, Daniel Andreas Schmitter, Ricard Delgado Gonzalo

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 ...

IEEE2014

Advanced Image Processing for Biology, and the Open Bio Image Alliance (OBIA)

Michaël Unser, Daniel Sage, Ricard Delgado Gonzalo

The field of biological imaging has evolved considerably during the past decade as a result of recent (r)evolutions in fluorescence labeling and optical microscopy. Bioimage informatics has been identified as a top priority to cope with the ever-increasing ...

EUSIPCO2013

Spline-based framework for interactive segmentation in biomedical imaging

Michaël Unser, Ricard Delgado Gonzalo

Active contours constitute a computationally attractive framework for image segmentation. In this paper, we describe a fully parametric design that relies on B-spline bases and is specified by control points on the image. Our technique yields successful se ...

Elsevier Science Inc2013

Spline-Based Deforming Ellipsoids for Interactive 3D Bioimage Segmentation

Michaël Unser, Ricard Delgado Gonzalo

We present a new fast active-contour model (a.k.a. snake) for image segmentation in 3D microscopy. We introduce a parametric design that relies on exponential B-spline bases and allows us to build snakes that are able to reproduce ellipsoids. We design our ...

Ieee-Inst Electrical Electronics Engineers Inc2013

A chemostat array enables the spatio-temporal analysis of the yeast proteome

Felix Naef, Michaël Unser, Nicolas Dénervaud, Sebastian Maerkl, Ricard Delgado Gonzalo, Arun Stephen Rajkumar, Johannes Becker

Observing cellular responses to perturbations is central to generating and testing hypotheses in biology. We developed a massively parallel microchemostat array capable of growing and observing 1,152 yeast-GFP strains on the single-cell level with 20 min t ...

National Academy of Sciences2013

Segmentation and Tracking in High-Throughput Bioimaging

Ricard Delgado Gonzalo

EPFL2013

Exponential splines and minimal-support bases for curve representation

Philippe Thévenaz, Michaël Unser, Ricard Delgado Gonzalo

Our interest is to characterize the spline-like integer-shift-invariant bases capable of reproducing exponential polynomial curves. We prove that any compact-support function that reproduces a subspace of the exponential polynomials can be expressed as the ...

Elsevier2012

Snakes With an Ellipse-Reproducing Property

Philippe Thévenaz, Michaël Unser, Chandra Sekhar Seelamantula, Ricard Delgado Gonzalo

We present a new class of continuously defined parametric snakes using a special kind of exponential splines as basis functions. We have enforced our bases to have the shortest possible support subject to some design constraints to maximize efficiency. Whi ...

IEEE2012

Fast Parametric Snakes For 3D Microscopy

Michaël Unser, Ricard Delgado Gonzalo

We present a new fast active contour for images in 3D microscopy. We introduce a fully parametric design that relies on exponential B-spline bases and allows us to impose a sphere-like topology. The proposed 3D snake can approximate blob-like objects with ...

Ieee2012

A New Hybrid Bayesian-Variational Particle Filter With Application To Mitotic Cell Tracking

Michaël Unser, Ricard Delgado Gonzalo

Tracking algorithms are traditionally based on either a variational approach or a Bayesian one. In the variational case, a cost function is established between two consecutive frames and minimized by standard optimization algorithms. In the Bayesian case, ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011

Variational Enhancement And Denoising Of Flow Field Images

Michaël Unser, Pouya Dehghani Tafti, Ricard Delgado Gonzalo

In this work we propose a variational reconstruction algorithm for enhancement and denoising of flow fields that is reminiscent of total-variation (TV) regularization used in image processing, but which also takes into account physical properties of flow s ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011