Home

Person

Adam James Scholefield

This person has left EPFL

About
Privacy
Disclaimer

Graph Chatbot

Related publications (25)

Page 1 of 2

Sampling at unknown locations: Uniqueness and reconstruction under constraints

Martin Vetterli, Adam James Scholefield, Benjamin Bejar Haro, Golnooshsadat Elhami, Michalina Wanda Pacholska

Traditional sampling results assume that the sample locations are known. Motivated by simultaneous localization and mapping (SLAM) and structure from motion (SfM), we investigate sampling at unknown locations. Without further constraints, the problem is of ...

2018

Embedded Polarizing Filters to Separate Diffuse and Specular Reflection

Adam James Scholefield, Gilles Baechler, Laurent Valentin Jospin

Polarizing filters provide a powerful way to separate diffuse and specular reflection; however, traditional methods rely on several captures and require proper alignment of the filters. Recently, camera manufacturers have proposed to embed polarizing micro ...

SPRINGER INTERNATIONAL PUBLISHING AG2019

Sampling at unknown locations, with an application in surface retrieval

Martin Vetterli, Adam James Scholefield, Benjamin Bejar Haro, Michalina Wanda Pacholska

We consider the problem of sampling at unknown locations. We prove that, in this setting, if we take arbitrarily many samples of a polynomial or real bandlimited signal, it is possible to find another function in the same class, arbitrarily far away from t ...

2017

Lippmann Photography: A Signal Processing Perspective

Martin Vetterli, Adam James Scholefield, Gilles Baechler, Michalina Wanda Pacholska, Arnaud Latty

Lippmann (or interferential) photography is the first and only analog photography method that can capture the full color spectrum of a scene in a single take. This technique, invented more than a hundred years ago, records the colors by creating interferen ...

2022

Encoding And Decoding Mixed Bandlimited Signals Using Spiking Integrate-And-Fire Neurons

Martin Vetterli, Adam James Scholefield, Karen Adam

Conventional sampling focuses on encoding and decoding bandlimited signals by recording signal amplitudes at known time points. Alternately, sampling can be approached using biologically-inspired schemes. Among these are integrate-and-fire time encoding ma ...

IEEE2020

How Asynchronous Events Encode Video

Martin Vetterli, Adam James Scholefield, Karen Adam

As event-based sensing gains in popularity, theoretical understanding is needed to harness this technology’s potential. Instead of recording video by capturing frames, event-based cameras have sensors that emit events when their inputs change, thus encodin ...

IEEE2021

Realizability of planar point embeddings from angle measurements

Majed El Helou, Adam James Scholefield, Frederike Dümbgen

Localization of a set of nodes is an important and a thoroughly researched problem in robotics and sensor networks. This paper is concerned with the theory of localization from inner-angle measurements. We focus on the challenging case where no anchor loca ...

IEEE2020

Unlabeled Sensing: Reconstruction Algorithm and Theoretical Guarantees

Martin Vetterli, Adam James Scholefield, Benjamin Bejar Haro, Golnooshsadat Elhami

It often happens that we are interested in reconstructing an unknown signal from partial measurements. Also, it is typically assumed that the location (temporal or spatial) of the samples is known and that the only distortion present in the observations is ...

Ieee2017

Blind as a Bat: Audible Echolocation on Small Robots

Martin Vetterli, Adam James Scholefield, Mihailo Kolundzija, Frederike Dümbgen, Adrien Guillaume Olivier Hoffet

For safe and efficient operation, mobile robots need to perceive their environment, and in particular, perform tasks such as obstacle detection, localization, and mapping. Although robots are often equipped with microphones and speakers, the audio modality ...

2022

Sampling and Exact Reconstruction of Pulses with Variable Width

Martin Vetterli, Adam James Scholefield, Gilles Baechler, Loïc Arnaud Baboulaz

Recent sampling results enable the reconstruction of signals composed of streams of fixed-shaped pulses. These results have found applications in topics as varied as channel estimation, biomedical imaging and radio astronomy. However, in many real signals, ...

Institute of Electrical and Electronics Engineers2017

Sampling and Reconstruction of Bandlimited Signals with Multi-Channel Time Encoding

Martin Vetterli, Adam James Scholefield, Karen Adam

Sampling is classically performed by recording the amplitude of the input at given time instants; however, sampling and reconstructing a signal using multiple devices in parallel becomes a more difficult problem to solve when the devices have an unknown sh ...

2020

Combining Range and Direction for Improved Localization

Martin Vetterli, Adam James Scholefield, Gilles Baechler, Robin Scheibler, Frederike Dümbgen, Golnooshsadat Elhami, Miranda Krekovic

Self-localization of nodes in a sensor network is typically achieved using either range or direction measurements; in this paper, we show that a constructive combination of both improves the estimation. We propose two localization algorithms that make use ...

2018

Shape from bandwidth: the 2-D orthogonal projection case

Martin Vetterli, Adam James Scholefield, Benjamin Bejar Haro

Could bandwidth—one of the most classic concepts in signal processing—have a new purpose? In this paper, we investigate the feasibility of using bandwidth to infer shape from a single image. As a first analysis, we limit our attention to orthographic proje ...

Ieee2017

Point and sensor estimation from images

Martin Vetterli, Adam James Scholefield, Alireza Ghasemi

System comprising at least one sensor configured to take a set of images from different viewpoints of a scene; a processor configured to identifying a point source represented in the images of a set of images; computing for each image of the set of images ...

2017

Multi-channel Time Encoding for Improved Reconstruction of Bandlimited Signals

Martin Vetterli, Adam James Scholefield, Karen Adam

Traditional sampling involves encoding a signal through (time, value)-pairs. In contrast, time encoding machines (TEMs) characterize a signal by recording time points which depend on the integral of the signal over time. We study multi-channel TEMs where c ...

2019

Three-Dimensional Cubic Barcodes

Martin Vetterli, Adam James Scholefield, Golnooshsadat Elhami

We consider three-dimensional cubic barcodes, consisting of smaller cubes, each built from one of two possible materials and carry one bit of information. To retrieve the information stored in the barcode, we measure a 2-D projection of the barcode using a ...

2022

Bound and Conquer: Improving Triangulation by Enforcing Consistency

Martin Vetterli, Adam James Scholefield, Alireza Ghasemi

We study the accuracy of triangulation in multi-camera systems with respect to the number of cameras. We show that, under certain conditions, the optimal achievable reconstruction error decays quadratically as more cameras are added to the system. Furtherm ...

2019

Shape From Bandwidth: Central Projection Case

Martin Vetterli, Adam James Scholefield, Golnooshsadat Elhami

Consider an unknown surface painted with a band-limited texture. We show that only the knowledge of the bandwidth of the texture is enough to estimate the shape of the surface from a single image taken by a camera. We model the problem as a central project ...

IEEE2020

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

Martin Vetterli, Adam James Scholefield, Alireza Ghasemi

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 ...

2015

Multi-spectral image priniting method

Martin Vetterli, Yves Bellouard, Adam James Scholefield, Gilles Baechler, Michalina Wanda Pacholska, Arnaud Latty

The present disclosure concerns a multi-spectral image printing method. The method includes the steps of: - providing a multi-spectral image; - providing a material; - determining changes in a refractive index value of the material permitting to reproduce ...

2019