english only
Biomedical Imaging Group
Seminars
 EPFL > BIG > Seminars Login
 Recent 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 Order by   Categorie Date Title Speaker    Ascending Descending

Harshit Gupta
EPFL STI LIB

14:00

In this talk, I will present CNN-based projection on the data manifold as a new regularization scheme. Classical and iterative algorithms regularize the inverse problems by imposing prior on the real world data which is not true (like smoothness by $\ell_2$-norm and sharp edges by TV-norm). This results in solutions which are increasingly far from the true solutions as the ill-posedness of the problem increases. CNNs trained as high-dimensional (image-to-image) regressors have recently been used to efficiently solve inverse problems in imaging. However, these approaches not only lack any regularization but also are not able to enforce data fidelity and therefore, are unreliable in terms of the prior they impose and the measurement consistency of their solution. I will show that our scheme is built on the framework of Projected Gradient Descent (PGD) where the projector is replaced by the trained CNN. The gradient descent enforces the data fidelity, while the CNN recursively projects the solution closer to the space of desired reconstruction images. Since the projector is replaced with a CNN, I will present a relaxed PGD, which always converges. I will discuss a simple scheme to train a CNN to act like a projector. Finally, I will present experiments on sparse view Computed Tomography (CT) reconstruction for both noiseless and noisy measurements which show an improvement over the total-variation (TV) method and a recent CNN based technique.

Emmanuel Soubies
EPFL STI LIB

Thomas Debarre
EPFL STI LIB

Prof. Ahmed I. Zayed
Department of Mathematical Sciences DePaul University

First steps toward fast PET reconstruction30 May 2017

Mike McCann
EPFL STI LIB

Nicolas Chiaruttini
University of Geneva

Thanh-an Pham
EPFL STI LIB

Laurène Donati
EPFL STI LIB

Chasing Mycobacteria10 Apr 2017

Virginie Uhlmann
EPFL STI LIB

Stéphane Jaffard
UPEC

Emmanuel Soubies
EPFL STI LIB

Denis Fortun
EPFL STI LIB

Harshit Gupta
EPFL STI LIB

Ferréol Soulez
EPFL STI LIB

Kyong Jin
EPFL STI LIB

EPFL STI LIB

Prof. Michael Leibling
Idap Research Institute

Luc Zeng
EPFL STI LIB

Ha Nguyen
EPFL STI LIB

SIGGRAPH ASIA 201601 Nov 2016

Daniel Schmitter
EPFL STI LIB

Lévy's Persian summers18 Oct 2016

Julien Fageot
EPFL STI LIB

Mike McCann
EPFL STI LIB

Algorithmic Aspects of Compressive Sensing03 Oct 2016

Verner Vlacic
Cambridge University

ICIP 201620 Sep 2016

EPFL STI LIB

Machine Vision forum in Heidelberg17 Aug 2016

Virginie Uhlmann
EPFL STI LIB

Kyong Jin
EPFL STI LIB

Laurène Donati
EPFL STI LIB

Ha Nguyen
EPFL STI LIB

Ferréol Soulez
EPFL STI LIB

Virginie Uhlmann
EPFL STI LIB