Publications associées à Subjective and objective evaluation of HDR video compression

Towards a multiscale point cloud structural similarity metric

Touradj Ebrahimi, Davi Nachtigall Lazzarotto

Point clouds are effective data structures for the rep- resentation of three-dimensional media and hence adopted in a wide range of practical applications. In many cases, the portrayed data is expected to be visualized by humans. After acquisition, point c ...

IEEE2023

Saliency prediction in 360° architectural scenes: Performance and impact of daylight variations

Marilyne Andersen, Sabine Süsstrunk, Kynthia Chamilothori, Bahar Aydemir, Caroline Karmann, Seungryong Kim

Saliency models are image-based prediction models that estimate human visual attention. Such models, when applied to architectural spaces, could pave the way for design decisions where visual attention is taken into account. In this study, we tested the pe ...

2023

Feature-based no-reference video quality assessment using Extra Trees

Arash Amini, Hatef Otroshi Shahreza

With the emergence of social networks and improvements in the internet speed, the video data has become an ever-increasing portion of the global internet traffic. Besides the content, the quality of a video sequence is an important issue at the user end wh ...

WILEY2022

Towards Quantum 3D Imaging Devices

Claudio Bruschini, Edoardo Charbon, Samuel Burri, Arin Can Ülkü, Paul Mos, Michael Alan Wayne

We review the advancement of the research toward the design and implementation of quantum plenoptic cameras, radically novel 3D imaging devices that exploit both momentum–position entanglement and photon–number correlations to provide the typical refocusin ...

2021

High dynamic range image sharing with privacy protection

Touradj Ebrahimi, Evgeniy Upenik, Pol Fernandez Marti

Sharing pictures has become a very popular practice among consumers. Most recent cameras, displays, and smartphones can capture and display images in high dynamic range and wide colour gamut, contributing to an increase of this type of content. It is a wel ...

SPIE2020

Evolution of Cortical and White Matter Lesion Load in Early-Stage Multiple Sclerosis: Correlation With Neuroaxonal Damage and Clinical Changes

Meritxell Bach Cuadra, Guillaume Bonnier, Cristina Granziera, Mario Joao Fartaria de Oliveira, Po-Jui Lu

Introduction:Changes in cortical and white matter lesion (CL, WML) load are pivotal metrics to diagnose and monitor multiple sclerosis patients. Yet, the relationship between (i) changes in CL/WML load and disease progression and between (ii) changes in CL ...

FRONTIERS MEDIA SA2020

Point cloud quality evaluation: Towards a definition for test conditions

Touradj Ebrahimi, Rafael Xavier Meriade Duarte, Evangelos Alexiou

Recently stakeholders in the area of multimedia representation and transmission have been looking at plenoptic technologies to improve immersive experience. Among these technologies, point clouds denote a volumetric information representation format with i ...

2019

Association between Brain and Plasma Glutamine Levels in Healthy Young Subjects Investigated by MRS and LC/MS

Lijing Xin, Yuhei Takado

Both glutamine (Gln) and glutamate (Glu) are known to exist in plasma and brain. However, despite the assumed relationship between brain and plasma, no studies have clarified the association between them. Proton magnetic resonance spectroscopy (MRS) was se ...

2019

Rendering-dependent compression and quality evaluation for light field contents

Touradj Ebrahimi, Irene Viola

Light field representation promises to overcome the limitations of stereoscopic representation by allowing for a more seamless transition between multiple points of views, thus giving a more faithful representation of 3D scenes. However, in order to take f ...

2019

Compression and visual quality assessment for light field contents

Irene Viola

Since its invention in the 19th century, photography has allowed to create durable images of the world around us by capturing the intensity of light that flows through a scene, first analogically by using light-sensitive material, and then, with the advent ...

EPFL2019

Design and Validation of a Compact Embedded Photometric Device for Real-time Daylighting Computing in Office Buildings

Jean-Louis Scartezzini, Jérôme Henri Kämpf, Yujie Wu

Studies have shown that the exposure to daylight can have substantial visual/non-visual benefits for building occupants. To optimise daylighting provision while maintaining a comfortable visual environment, daylighting control systems have been investigate ...

2019

Quality assessment of an HDR dual-layer backward-compatible codec compared to uncompromised SDR and HDR solutions

Touradj Ebrahimi, Martin Rerabek, Anne-Flore Nicole Marie Perrin

Broadcasting high dynamic range (HDR) video has been demonstrated as largely preferred when compared to standard dynamic range (SDR), mainly due to its capability of representing more details in dark and bright regions. Additionally, progress over the last ...

2018

VALID: Visual quality Assessment for Light field Images Dataset

Touradj Ebrahimi, Irene Viola

In the last years, light field imaging has experienced a surge of popularity among the scientific community for its capability of rendering the 3D world in a more immersive way. In particular, several compression algorithms have been proposed to efficientl ...

2018

Comparison of Compression Efficiency between HEVC/H.265, VP9 and AV1 based on Subjective Quality Assessments

Touradj Ebrahimi, Pinar Akyazi

The growing requirements for broadcasting and streaming of high quality video continue to trigger demands for codecs with higher compression efficiency. AV1 is the most recent open and royalty free video coding specification developed by Alliance for Open ...

2018

Comparison of Interactive Subjective Methodologies for Light Field Quality Evaluation

Touradj Ebrahimi, Irene Viola

The recent advances in light field acquisition and rendering technologies have attracted a lot of interest from the scientific community. Due to their large amount of data, efficient compression of light field content is of paramount importance for storage ...

2018

On the Use of Transfer Entropy to Investigate the Time Horizon of Causal Influences between Signals

Patrick Blanchard, Basil Duval, Ambrogio Fasoli, Yves Martin, Richard Pitts, Olivier Sauter, Henri Weisen, Robin Humphry-Baker, Stefano Coda, Martinus Gijs, Partha Dutta, Marco Wischmeier, Jan Horacek, Vlad Trifa, Yann Camenen, Jonathan Graves, Duccio Testa, Miguel Fernández Ruiz, Sun Hee Kim, Mikhail Maslov, Javier García Hernández, David Pfefferlé, José Pedro Rebelo Ferreira Marques, Julio Rodriguez, Pedro Camilo de Oliveira e Silva, Rebecca Hill, Daniel Scott Alessi, Jonnathan Cesar Hidalgo Acosta, Ana Francisca Leal Silva Soares, Dalziel Joseph Wilson, Pierre-Thomas Paul Brun, Jonathan Marc Philippe Faustin, Federico Nespoli, Alberto Hernando de Castro, Hamish William Patten, Bruno Emanuel Ferreira De Sousa Correia, Li Shuai, Nicola Vianello, Antonio José Pereira de Figueiredo, , , , , , , , ,

Point cloud subjective evaluation methodology based on reconstructed surfaces

Touradj Ebrahimi, Evangelos Alexiou

Point clouds have been gaining importance as a solution to the problem of efficient representation of 3D geometric and visual information. They are commonly represented by large amounts of data, and compression schemes are important for their manipulation ...

SPIE-INT SOC OPTICAL ENGINEERING2018

Financial Ratios as Indicators of Economic Sustainability: A Quantitative Analysis for Swiss Dairy Farms

Ivo Philippe Baur

In agriculture, a rising number of sustainability assessments are available that also comprise financial ratios. In a literature review of farm management textbooks, taking account of the differences between European and North American practices and consid ...

MDPI2018

On the performance of metrics to predict quality in point cloud representations

Touradj Ebrahimi, Evangelos Alexiou

Point clouds are a promising alternative for immersive representation of visual contents. Recently, an increased interest has been observed in the acquisition, processing and rendering of this modality. Although subjective and objective evaluations are cri ...

Spie-Int Soc Optical Engineering2017

Evaluation of JPEG XT for high dynamic range cameras

Touradj Ebrahimi, Philippe Hanhart

Modern cameras can be used to capture high dynamic range (HDR) images by taking multiple low dynamic range (LDR) pictures at different exposure settings. However, DSLR cameras often store the multiple exposure pictures, which increases storage requirements ...

Elsevier Science Bv2017