Publications de Roberto Gerson De Albuquerque Azevedo

Quality-Constrained Encoding Optimization for Omnidirectional Video Streaming

Pascal Frossard, Roberto Gerson De Albuquerque Azevedo, Chaofan He

Omnidirectional video streaming is usually implemented based on the representations of tiles, where the tiles are obtained by splitting the video frame into several rectangular areas and each tile is converted into multiple representations with different r ...

Ieee-Inst Electrical Electronics Engineers Inc2023

OSLO: On-the-Sphere Learning for Omnidirectional Images and Its Application to 360-Degree Image Compression

Pascal Frossard, Thomas Maugey, Roberto Gerson De Albuquerque Azevedo

State-of-the-art 2D image compression schemes rely on the power of convolutional neural networks (CNNs). Although CNNs offer promising perspectives for 2D image compression, extending such models to omnidirectional images is not straightforward. First, omn ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

Visual Distortions in 360-degree Videos

Pascal Frossard, Roberto Gerson De Albuquerque Azevedo, Francesca De Simone

Omnidirectional (or 360-degree) images and videos are emergent signals being used in many areas such as robotics and virtual/augmented reality. In particular, for virtual reality applications, they allow an immersive experience in which the user can intera ...

2020

Subjective and Viewport-based Objective Quality Assessment of 360-degree Videos

Pascal Frossard, Roberto Gerson De Albuquerque Azevedo

Visual distortions in processed 360-degree visual content and consumed through head-mounted displays (HMDs) are perceived very differently when compared to traditional 2D content. To better understand how compression-related artifacts affect the overall pe ...

2020

A Viewport-driven Multi-metric Fusion Approach for 360-Degree Video Quality Assessment

Pascal Frossard, Roberto Gerson De Albuquerque Azevedo

We propose a new viewport-based multi-metric fusion (MMF) approach for visual quality assessment of 360-degree (omnidirectional) videos. Our method is based on computing multiple spatio-temporal objective quality metrics (features) on viewports extracted f ...

IEEE2020

An Authoring Model For Interactive 360 Videos

Roberto Gerson De Albuquerque Azevedo

The recent availability of consumer-level head-mounted displays and omnidirectional cameras has been driving an explosion of 360 video content. Transforming the original recorded 360 video content in meaningful interactive multimedia presentations that sup ...

IEEE2020

Subjective Evaluation of 360-degree Sensory Experiences

Pascal Frossard, Roberto Gerson De Albuquerque Azevedo

Traditionally, most multimedia content has been developed to stimulate two of the human senses, i.e., sight and hearing. Due to recent technological advancements, however, innovative services have been developed that provide more realistic, immersive, and ...

IEEE2019

On the first JND and break in presence of 360-degree content

Pascal Frossard, Roberto Gerson De Albuquerque Azevedo

Unlike traditional planar 2D visual content, immersive 360-degree images and videos undergo particular processing steps and are intended to be consumed via head-mounted displays (HMDs). To get a deeper understanding on the perception of 360-degree visual d ...

ACM Press2019

Graph-Based Detection of Seams In 360-Degree Images

Pascal Frossard, Francesca De Simone, Sohyeong Kim, Roberto Gerson De Albuquerque Azevedo

In this paper, we propose an algorithm to detect a specific kind of distortions, referred to as seams, which commonly occur when a 360-degree image is represented in planar domain by projecting the sphere to a polyhedron, e.g, via the Cube Map (CM) project ...

2019

Visual Distortions in 360-degree videos (Dataset)

Pascal Frossard, Francesca De Simone, Roberto Gerson De Albuquerque Azevedo

Here we catalog, visually demonstrate, and discuss the main causes of commonly encountered visual distortions into current 360-degree video processing pipelines. The main goal of the samples in this dataset is to demonstrate the visual distortions discusse ...

2019