Publications by Effrosyni Kokiopoulou

Distributed average consensus with quantization refinement

Pascal Frossard, Ntorina Thanou, Ye Pu, Effrosyni Kokiopoulou

We consider the problem of distributed average consensus in a sensor network where sensors exchange quantized information with their neighbors. We propose a novel quantization scheme that exploits the increasing correlation between the values exchanged by ...

Institute of Electrical and Electronics Engineers2013

Progressive quantization in distributed average consensus

Pascal Frossard, Effrosyni Kokiopoulou, Ntorina Thanou

We consider the problem of distributed average consensus in a sensor network where sensors exchange quantized information with their neighbors. In particular, we exploit the increasing correlation between the exchanged values throughout the iterations of t ...

2012

Distributed classification of multiple observation sets by consensus

Pascal Frossard, Effrosyni Kokiopoulou

We consider the problem of distributed classification of multiple observations of the same object that are collected in an ad hoc network of vision sensors. Assuming that each sensor captures a different observation of the same object, the problem is to cl ...

Institute of Electrical and Electronics Engineers2011

Optimal image alignment with random projections of manifolds: algorithm and geometric analysis

Pascal Frossard, Daniel Kressner, Effrosyni Kokiopoulou

This paper addresses the problem of image alignment based on random measurements. Image alignment consists of estimating the relative transformation between a query image and a reference image. We consider the specific problem where the query image is prov ...

2011

Graph-based classification of multiple observation sets

Pascal Frossard, Effrosyni Kokiopoulou

We consider the problem of classification of multiple observations of the same object, possibly under different transformations. We view this problem as a special case of semi-supervised learning where all unlabelled examples belong to the same unknown cla ...

Elsevier2010

On the curvature of pattern transformation manifolds: Numerical estimation and applications

Pascal Frossard, Daniel Kressner, Effrosyni Kokiopoulou

2010

Polynomial Filter Design for Quantized Consensus

Pascal Frossard, Ntorina Thanou, Effrosyni Kokiopoulou, Hyung Gon Park

We consider the problem of distributed average consensus where sensors exchange quantized data with their neighbors. We deploy a polynomial filtering approach in the network nodes in order to accelerate the convergence of the consensus problem. The quantiz ...

2010

3D Face Recognition with Sparse Spherical Representations

Pascal Frossard, Effrosyni Kokiopoulou, Ivana Tosic, Roser Sala Llonch

This paper addresses the problem of 3D face recognition using simultaneous sparse approximations on the sphere. The 3D face point clouds are first aligned with a novel and fully automated registration process. They are then represented as signals on the 2D ...

2010

Distributed classification of multiple obervations by consensus

Pascal Frossard, Effrosyni Kokiopoulou

2010

Geometry-aware analysis of high-dimensional visual information sets

Effrosyni Kokiopoulou

Over the past few decades we have been experiencing a data explosion; massive amounts of data are increasingly collected and multimedia databases, such as YouTube and Flickr, are rapidly expanding. At the same time rapid technological advancements in mobil ...

EPFL2009