Publications associées à Method, system and computer program for determining a reflectance distribution function of an object

Practical Byzantine-resilient Stochastic Gradient Descent

Algorithms are everywhere. The recipe for the frangipane cake is an algorithm. If all the listed ingredients are available and the cook is sufficiently deft, after a finite number of small, well-defined steps a delicious dessert will exit the oven. Now, wh ...

EPFL2022

Pitfalls in the spectral measurements of polarization-altering metasurfaces

Olivier Martin, Hsiang-Chu Wang

The optical characterization of metasurfaces and nanostructures that alter the polarization of light is tricky and can lead to unphysical results, such as reflectance beyond unity. We track the origin of such pitfalls to the response of some typical optica ...

Optica Publishing Group2022

Effects of illuminance intensity on the green channel of remote photoplethysmography (rPPG) signals

Ata Jedari Golparvar

Point-of-care remote photoplethysmography (rPPG) devices that utilize low-cost RGB cameras have drawn considerable attention due to their convenience in contactless and non-invasive vital signs monitoring. In rPPG, sufficient lighting conditions are essent ...

SPRINGER2022

Light Path Gradients for Forward and Inverse Rendering

Tizian Lucien Zeltner

Physically based rendering is a process for photorealistic digital image synthesis and one of the core problems in computer graphics. It involves simulating the light transport, i.e. the emission, propagation, and scattering of light through a virtual scen ...

EPFL2021

Precise and accurate image-based measurements of optical material properties

Marjan Shahpaski

The appearance of objects is governed by how they reflect, transmit and absorb the light they receive. That, in turn, depends on the material's internal structure, surface structure, and viewing and illumination directions. Changes in those characteristics ...

EPFL2020

Effects of multiple scattering on angle-independent structural color in disordered colloidal materials

Sofia Magkiriadou

Disordered packings of colloidal spheres show angle-independent structural color when the particles are on the scale of the wavelength of visible light. Previous work has shown that the positions of the peaks in the reflectance spectra can be predicted acc ...

AMER PHYSICAL SOC2020

Large field of view multi-camera endoscopic apparatus with omni-directional illumination

Yusuf Leblebici, Ömer Cogal

A multi-camera hemispherical very wide field of view imaging apparatus with omnidirectional illumination capability comprises a cylindrical body (4, 4.a, 4.b), a hemispherical mechanical frame (2) arranged on one end of the cylindrical body (4, 4.a, 4.b), ...

2020

Ultra-Broadband and Omnidirectional Perfect Absorber Based on Copper Nanowire/Carbon Nanotube Hierarchical Structure

Giulia Tagliabue, Fateme Kiani Shahvandi, Theodoros Tsoulos

Zero reflection and complete light absorption are required in a wide range of applications ranging from sensing devices to solar heaters and photoelectrodes. However, simultaneously satisfying the requirements of the broadband spectrum, omnidirectionality, ...

AMER CHEMICAL SOC2020

System for personalized robotic therapy and related methods

Silvestro Micera, Nawal Noëlle Kinany, Elvira Pirondini, Christian Giang, Camilla Pierella

The present invention provides an apparatus and a method able to estimate motor improvement in real-time during three-dimensional rehabilitation tasks and to consequently dynamically personalize the therapy.The method can be carried out by a computer progr ...

2019

Sampling the Multiple Facets of Light

Gilles Baechler

The theme of this thesis revolves around three important manifestations of light, namely its corpuscular, wave and electromagnetic nature. Our goal is to exploit these principles to analyze, design and build imaging modalities by developing new signal proc ...

EPFL2018