Publications associées à High Speed Flow Visualisation of an Impinging Jet on a Pelton Turbine Bucket

LenslessPiCam: A Hardware and Software Platform for Lensless Computational Imaging with a Raspberry Pi

Martin Vetterli, Sepand Kashani, Matthieu Martin Jean-André Simeoni, Eric Bezzam

This toolkit has everything you need to perform imaging with a lensless camera. We make use of a low-cost implementation of DiffuserCam, namely replacing the lens with a piece of tape and using the Raspberry Pi HQ camera sensor. Similar principles and meth ...

Zenodo2023

Performance investigation of cameras using HDR sensors for daylight glare evaluations

Jan Wienold, Geraldine Cai Ting Quek, Dong Hyun Kim

This study presents a novel framework for evaluating the luminance measurement capabilities of High Dynamic Range (HDR) sensor cameras in indoor glare conditions. Results indicate that the practical usage range of the CSEM VIP camera is significantly lower ...

International Commission on Illumination2023

Towards learning-based denoising of light fields

Touradj Ebrahimi, Michela Testolina, Tomás Soares De Carvalho Feith

In recent years, new emerging immersive imaging modalities, e.g. light fields, have been receiving growing attention, becoming increasingly widespread over the years. Light fields are often captured through multi-camera arrays or plenoptic cameras, with th ...

2023

Numerical simulations of Pelton turbine flow to predict large head variation influence

François Avellan, Steve Crettenand, Cécile Münch-Alligné, Siamak Alimirzazadeh

In the framework of the new feed-in-tariff system in Switzerland for Small Hydropower Plants (SHP), the aim of the SmallFLEX project, led by HES-SO Valais and performed in collaboration with EPFL, WSL, EAWAG, PVE, and FMV, is to show how SHP can provide wi ...

IOP PUBLISHING LTD2021

A Pixel Design of a Branching Ultra-Highspeed Image Sensor

Edoardo Charbon

A burst image sensor named Hanabi, meaning fireworks in Japanese, includes a branching CCD and multiple CMOS readout circuits. The sensor is backside-illuminated with a light/charge guide pipe to minimize the temporal resolution by suppressing the horizont ...

2021

Perceiving Humans: from Monocular 3D Localization to Social Distancing

Alexandre Massoud Alahi, Sven Kreiss, Lorenzo Bertoni

Perceiving humans in the context of Intelligent Transportation Systems (ITS) often relies on multiple cameras or expensive LiDAR sensors. In this work, we present a new cost-effective vision-based method that perceives humans' locations in 3D and their bod ...

IEEE Institute of Electrical and Electronics Engineers2022

LiftPose3D, a deep learning-based approach for transforming two-dimensional to three-dimensional poses in laboratory animals

Pascal Fua, Pavan P Ramdya, Helge Jochen Rhodin, Semih Günel, Victor Lobato Rios, Daniel Eduardo Morales Garza, Marco Pietro Abrate, Adám Gosztolai

LiftPose3D infers three-dimensional poses from two-dimensional data or from limited three-dimensional data. The approach is illustrated for videos of behaving Drosophila, mice, rats and macaques. ...

NATURE PORTFOLIO2021

CFD simulations of a Y-junction for the implementation of hydraulic short-circuit operating mode

François Avellan, Cécile Münch-Alligné, Daniel Biner

In the framework of the XFLEX HYDRO H2020 European Project, one of the demonstrators focuses on the implementation of the hydraulic short-circuit on the pump storage power plant of Grand-Maison owned by Electricite De France (EDF). The Grand-Maison power p ...

IOP PUBLISHING LTD2021

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

Beyond Cameras: Real-Time High-Resolution 3D and Panoramic MultiView Vision Systems with Their Applications

Bilal Demir

The cameras are invented by imitating the human visual system to capture the scene. The camera technologies have been substantially advanced in recent years. 108 MP resolution with 100x hybrid zoom has become standard features for smartphone flagships. In ...

EPFL2020

Camera Calibration Models and Methods for Corridor Mapping with UAVs

Jan Skaloud, Davide Antonio Cucci, Emmanuel Pierre Quentin Clédat

Camera calibration refers to the modeling of the relationship between the coordinates of object points and their projections on the image plane. This is usually done by parametric models that describe the physical properties of the lens systems and camera ...

2020

Learning stereo reconstruction with deep neural networks

Stepan Tulyakov

Stereo reconstruction is a problem of recovering a 3d structure of a scene from a pair of images of the scene, acquired from different viewpoints. It has been investigated for decades and many successful methods were developed. The main drawback of these ...

EPFL2020

Simulation of CMOS APS Operation and Crosstalk in SPICE With Generalized Devices

Jean-Michel Sallese, Chiara Rossi

We present SPICE simulations of a CMOS APS pixel element consisting of the optical sensor with the sensing circuit. The photodiode is simulated at the physics level by means of the so-called Generalized Devices, without any predefined compact model. Conver ...

2020

A Neuro-Inspired Computational Model for a Visually Guided Robotic Lamprey Using Frame and Event Based Cameras

Auke Ijspeert, Alessandro Crespi, Alexandre Bernardino, Mehmet Hasan Mutlu, Simon Lukas Hauser, Jorg Conradt, Ibrahim Youssef Youssef

The computational load associated with computer vision is often prohibitive, and limits the capacity for on-board image analysis in compact mobile robots. Replicating the kind of feature detection and neural processing that animals excel at remains a chall ...

2020

Numerical investigation of the jet velocity profile and its influence on the Pelton turbine performance

François Avellan, Ebrahim Jahanbakhsh, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh, Audrey Paulette Solange Maertens, Takashi Kumashiro

Numerical investigation of the unsteady flow patterns around the bucket can be helpful to improve the Pelton turbine efficiency. In fact, by studying the loss mechanisms in the flow, one can optimize the bucket design. For this purpose, an accurate investi ...

IOP PUBLISHING LTD2019

GPU-accelerated Pelton turbine simulation using finite volume particle method coupled with linear eddy viscosity models

François Avellan, Ebrahim Jahanbakhsh, Sebastián Camilo Leguizamón Sarmiento, Siamak Alimirzazadeh, Audrey Paulette Solange Maertens, Takashi Kumashiro

The numerical investigation of the unsteady flow patterns around a Pelton bucket can be helpful to improve the overall turbine efficiency by optimizing the bucket design based on identified loss mechanisms. Since the flow is highly turbulent, modeling the ...

IOP PUBLISHING LTD2019

Active Near-Infrared Imaging for Spatio-Temporal Monitoring of a Solid Oxide Cell in Operation

Stefan Diethelm, Jan Van Herle, Guillaume Jeanmonod

The characterization of solid oxide cells (SOCs) relies mainly on direct-current (DC) and alternating-current (AC) methods that provide only average surface electro-chemical responses. As such, the spatial distribution is not well captured and the complexi ...

2019

Learning an event sequence embedding for event-based deep stereo

François Fleuret, Stepan Tulyakov, Michael Hirsch

Today, a frame-based camera is the sensor of choice for machine vision applications. However, these cameras, originally developed for acquisition of static images rather than for sensing of dynamic uncontrolled visual environments, suffer from high power c ...

IEEE2019

The virtual frame technique: ultrafast imaging with any camera

John Martin Kolinski

Many phenomena of interest in nature and industry occur rapidly and are difficult and cost-prohibitive to visualize properly without specialized cameras. Here we describe in detail the virtual frame technique (VFT), a simple, useful, and accessible mode of ...

2019

Real-time 360 Body Scanning System for Virtual Reality Research Applications

Bruno Herbelin, Olaf Blanke, Florian Lance, Louis Philippe Albert

We present a low-cost solution to perform the online and realistic representation of users using an array of depth cameras. The system is composed of a cluster of 10 Microsoft Kinect 2 cameras, each one associated to a compact NUC PC to stream live depth & ...

2019