Publications de Martin Vetterli

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We consider the problem of correlated data gathering by a network with a sink node and a tree based communication structure, where the goal is to minimize the total trans- mission cost of transporting the information collected by the nodes, to the sink nod ...

The authors state and prove a theorem solving the problem of commutativity in two dimensions. It is shown under which conditions upsampling and downsampling can be interchanged in two dimensions. This is the generalization to arbitrary two-dimensional lattices of the result that one-dimensional upsampling and downsampling commute if and only if their sampling rates are coprime. Some illustrative examples are given. The result holds for arbitrary sampling lattices.

In many networks, it is less costly to transmit a packet to any node in a set of neighbors than to one specific neighbor. This observation was previously exploited by opportunistic routing protocols by using single-path routing metrics to assign to each no ...

Although many advances have been made in light-field and camera-array image processing, there is still a lack of thorough analysis of the localisation accuracy of different multi-camera systems. By considering the problem from a frame-quantisation perspect ...

Energy efficiency of wireless sensor networks (WSNs) can be improved by moving base stations (BSs), as this scheme evenly distributes the communication load in the network. However, physically moving BSs is complicated and costly. In this paper, we propose ...

The literature on gradient and differential microphone arrays makes a distinction between the two types, and nevertheless shows how both types can be used to obtain the same directional responses. A more theoretically sound rationale for using delays in di ...

In this paper, we present a modular approach for reconstructing lensless measurements. It consists of three components: a newly-proposed pre-processor, a physics-based camera inverter to undo the multiplexing of lensless imaging, and a post-processor. The ...

An important field of application for wireless sensor networks is environmental monitoring. Given the importance of potential climate changes, environmental impact on cities, and pollution, it is an application domain where sensor networks can have great i ...

We study the spatio-temporal sampling of a diffusion field driven by K unknown instantaneous source distributions. Exploiting the spatio-temporal correlation offered by the diffusion model, we show that it is possible to compensate for insufficient spatial ...

We present the concept of an acoustic rake receiver—a microphone beamformer that uses echoes to improve the noise and interference suppression. The rake idea is well-known in wireless communications; it involves constructively combining different multipath ...

Imagine that you are blindfolded inside an unknown room. You snap your fingers and listen to the room’s response. Can you hear the shape of the room? Some people can do it naturally, but can we design computer algorithms that hear rooms? We show how to com ...

Calibration of ultrasound tomography devices is a challenging problem and of highly practical interest in medical and seismic imaging. This work addresses the position calibration problem in circular apertures where sensors are arranged on a circular ring and act both as transmitters and receivers.We introduce a new method of calibration based on the time-of-flight (ToF) measurements between sensors when the enclosed medium is homogeneous. Knowing all the pairwise ToFs, one can find the positions of the sen

A data storage medium (2) comprising a stacked plurality of layers (9), each layer composed of a layer material selected from a group comprising at least two different dielectric materials, adjacent layers being formed of different materials, and at least ...

We address the problem of sampling and reconstruction of sparse signals with finite rate of innovation. We derive general conditions under which perfect reconstruction is possible for sampling kernels satisfying Strang-Fix conditions. Previous results on t ...

We study the problem of privacy-preserving computation of functions of data that belong to users in a social network under the assumption that users are willing to share their private data with trusted friends in the network. We demonstrate that such trust ...

This correspondence deals with multiwavelets, which are a recent generalization of wavelets in the context of time-varying filter banks and with their applications to signal processing and especially com- pression. By their inherent structure, multiwavelets are fit for processing multichannel signals. This is the main issue in which we will be interested here. The outline of the correspondence is as follows. First, we will review material on multiwavelets and their links with multifilter banks and, especial

A method for presenting to a user of a wearable audio device a modified audio scene together with additional information related to the audio scene, comprising: capturing audio signals with a plurality of microphones; outputting an audio signal with a plur ...

We consider the problem of reconstructing superimposed temperature and wind flow fields from acoustic measurements. A new technique based solely on acoustic wave propagation is presented. In contrast to the usual straight ray assumption, a bent ray model i ...

We demonstrate a throughput increase of third-harmonic generation microscopy imaging using arbitrary illumination patterns. A ‘camera-in-the-loop’ feedback control optimizes the hologram displayed by a spatial light modulator and two different image reconstruction methods are implemented.

The successful deployment of a wireless sensor network is a difficult task, littered with traps and pitfalls. Even a functional network does not guarantee gathering meaningful data. In SensorScope, with its high-mountain campaigns, we have acquired invalua ...

Martin Vetterli

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Network Correlated Data Gathering with Explicit Communication: NP-Completeness and Algorithms

The commutativity of up- and down-sampling in two dimensions

Valuable Detours: Least-Cost Anypath Routing

On the Accuracy of Point Localisation in a Circular Camera-Array

Virtually Moving Base Stations for Energy Efficiency in Wireless Sensor Networks

Spatiotemporal Gradient Analysis of Differential Microphone Arrays

A Modular and Robust Physics-Based Approach for Lensless Image Reconstruction

SensorScope: Out-of-the-Box Environmental Monitoring

Distributed Spatio-Temporal Sampling of Diffusion Fields from Sparse Instantaneous Sources

Raking the Cocktail Party

Acoustic Echoes Reveal Room Shape

Ultrasound Tomography Calibration Using Structured Matrix Completion

Non-volatile data storage medium and system

Sampling Continuous-time Sparse Signals: A Frequency-domain Perspective

Privacy-Preserving Function Computation by Exploitation of Friendships in Social Networks

High-order balanced multiwavelets: theory, factorization, and design

Method and apparatus for presenting to a user of a wearable apparatus additional information related to an audio scene

Acoustic tomography for estimating temperature and wind flow

Holographic Illumination for Fast Wide-Field Third-Harmonic Generation Imaging

The Hitchhiker's Guide to Successful Wireless Sensor Network Deployments