Mylene C. Q. Farias

University of Brasília | UnB · Department of Electrical Engineering

Television (TV) stands out as the most popular communication media in Brazil, with a pervasive presence in countless Brazilian households. Its influence extends beyond mere entertainment, serving as a unifying force in a country as vast as Brazil, fostering a shared cultural experience and playing a crucial role in shaping a collective identity. Es...

Stereo image super-resolution (SR) aims to increase the spatial resolutions of the left and right views of a stereo image in an attempt to generate higher-resolutions views that appear visually equivalent to those obtained with a higher-resolution stereo camera. The field of stereo image SR has seen rapid significant progress due in large part to t...

The 13th ACM Multimedia Systems Conference (and its associated workshops: MMVE 2022, NOSSDAV 2022, and GameSys 2022) took place from the 14th -- 17th of June 2022 in Athlone, Ireland. The week after, the ACM International Conference on Interactive Media Experiences took place in Aveiro, Portugal from the 22nd -- 24th of June. Both conferences are s...

Since the mid-20th century, the use of digital formats for visual content has revolutionized communication in society. The Internet and digital broadcasting systems, which became widely available in the 1990s, led to an incredible expansion of multimedia consumption among the public. As a result, telecommunication networks and providers were pushed...

Early detection of cancer tumors significantly increases the chances of recovery and usually results in improved quality of life and patient lifespan. In this context, computer systems can help and accelerate health care decision making regarding brain diagnoses, based, for example, on machine learning (ML) algorithms applied to neurological magnet...

We consider the automatic hardness determination of a chest X-ray image and the effect of pre-filtering of the training and validation samples on the performance of the classification algorithm of tuberculosis diagnosis from chest X-rays. Convolutional neural networks are used in automatic hardness determination and tuberculosis diagnosis. The resu...

Unlike traditional cameras, Light Field (LF) cameras are able to capture both the intensity and direction of light rays from the scene. This rich information demands a certain amount of memory and bandwidth for storage and transmission, and to alleviate this requirement, LF content is processed and compressed. These operations often add degradation...

Optimizing user quality of experience (QoE) for 360° videos faces two major roadblocks: inaccurate viewport prediction and viewers missing the plot of a story. To tackle these issues simultaneously, alignment edits have emerged as a promising solution. These edits, also known as "re-targeting edits," work by aligning the user’s field of view with a...

Since the mid-20th century, the use of digital formats for visual content allowed a great evolution in how society communicates. The Internet and digital broadcast systems introduced in the decade 90 to the wider public allowed an incredible expansion of multimedia consumption by the people, while the telecommunication networks and providers were p...

This work introduces a Quality Assessment Framework that provides researchers with the flexibility, consistency, and scalability they need to evaluate and compare quality metrics, promoting the reproducibility of results. The framework is open source (Python) and currently has 11 visual quality metrics that use 3 different libraries: Scikit-video,...

Point Cloud Quality Assessment (PCQA) has become an important task in immersive multimedia since it is fundamental for improving computer graphics applications and ensuring the best Quality of Experience (QoE) for the end user. In recent years, the field of PCQA has made exemplary progress, with state-of-the-art methods achieving better predictive...

This paper presents a set of developments for the design of a user-centric framework for perceptually efficient streaming of 360-degree edited videos. First, we introduce a software for annotation of regions of interest (RoI) in 360-degree videos with the goal of creating datasets for the training of machine learning-based visual attention computat...

Point Clouds (PCs) are collections of points distributed in the 3D space, containing attributes such as color, normals, transparency, and specularity. Dynamic Point Clouds (DPCs) correspond to sequences of points in the 3D space that vary over time like pixels vary over time in a conventional video. Dynamic PCs are a suitable way to represent volum...

Light Field (LF) cameras capture spatial and angular information of a scene, generating a high-dimensional data that brings several challenges to compression, transmission, and reconstruction algorithms. One research area that has been attracting a lot of attention is the design of Light Field images quality assessment (LF-IQA) methods. In this pap...

Light Field (LF) cameras are able to capture both the intensity and the direction of light rays from the scene. This rich information demands a certain amount of memory and bandwidth for storage and transmission and, to alleviate this requirement, the LF content is processed and compressed. These operations often add degradations to the LF content...

This paper contains the research proposal of Sana Alamgeer that was presented at the MMSys 2022 doctoral symposium. Unlike regular images that represent only light intensities, Light Field (LF) contents carry information about the intensity of light in a scene, including the direction light rays are traveling in space. This allows for a richer repr...

The optimization of viewers' quality of experience (QoE) in 360 videos faces two major roadblocks: inaccurate adaptive streaming and viewers missing the plot of a story. Alignment edit emerged as a promising mechanism to avoid both issues at once. Alignment edits act on the content, matching the users' viewport with a region of interest in the vide...

Methods for (PC) quality assessment customarily perform local comparisons between corresponding points in the “degraded” and pristine PCs. These methods often compare the geometry of the degraded PC and the geometry of the reference PC. More recently, a few methods that use texture information to assess the PC quality have been proposed. In this wo...

In recent years, 3D imaging technologies have advanced tremendously, allowing more faithful representations of the physical world. More specifically, imaging technology advancements have driven the production of plenoptic devices that can capture and display visual contents. These devices represent the visual data using an approximation of the plen...

This work aims to study the relations between Problem-Based Learning (PBL) approaches in engineering education and the evaluation methodology in an under graduation and multidisciplinary engineering discipline in the area of new product development. Students were divided into two classes: a basic Problem-Based Learning (PBL) approach, such as teamw...

We propose a yet lightweight no-reference (NR) video quality assessment (VQA) method, which uses a convolution neural network (CNN) architecture. The proposed method implements a spatiotemporal saliency patch selection procedure that crops the frame into small nonoverlapping blocks of images (patches) and selects the most perceptually relevant ones...

Audio-visual quality assessment remains as a complex research field. A great effort is being made to understand how visual and auditory domains are integrated and processed by humans. In this work, we analyzed and compared the results of three psychophisical experiments that collected quality and content scores given by a pool of subjects. The expe...

The interest in the use of the HF band in telecommunication has increased significantly in the last decade, mainly due to the development of new standards for military telecommunications in HF, as well as the expansion of digital broadcasting in the HF band. More specifically, these new standards allow the implementation of links of hundreds or tho...

Point Clouds (PCs) have recently been adopted as the preferred data structure for representing 3D visual contents. Examples of PC applications range from 3D representations of small objects up to large scenes, both still or dynamic in time. PC adoption triggered the development of new coding, transmission, and display methodologies that culminated...

Natural scene text classification is considered to be a challenging task because of diversified set of image contents, presence of degradations including noise, low contrast/resolution and the random appearance of foreground (font, style, sizes and orientations) and background properties. Above all, the high dimension of the input image’s feature s...

Images acquired in underwater scenarios may contain severe distortions due to light absorption and scattering, color distortion, poor visibility, and contrast reduction. Because of these degradations , researchers have proposed several algorithms to restore or enhance underwater images. One way to assess these algorithms' performance is to measure...

Viewport prediction technologies are often used by most popular adaptive 360-degree video streaming solutions. These solutions stream only the content considered as being more likely to be watched by the final user, with the goal of reducing the volume of network traffic without compromising the user’s Quality of Experience (QoE). In this paper, we...

According to Cisco, most Internet traffic is currently comprised of videos. Therefore, developing a quality assessment method for assuring that those videos are received and displayed with quality at the user side is an important and challenging task. As a consequence, over the last decades, several no-reference video quality metrics have been prop...

The No-reference Autoencoder VidEo (NAVE) metric is a video quality assessment model based on an autoencoder machine learning technique. The model uses an autoencoder to produce a set of features with a lower dimension and a higher descriptive capacity. NAVE has been shown to produce accurate quality predictions when tested with two video databases...

In recent years, PCs have become very popular for a wide range of applications, such as immersive virtual reality scenarios. As a consequence, in the last couple of years, there has been a great effort to develop novel acquisition, representation , compression, and transmission solutions for PC contents in the research community. In particular, the...

In recent years, there has been an increase in the popularity of Point Clouds (PC) as the preferred data structure for representing 3D visual contents. Examples of PC applications range from 3D representations of small objects up to large maps. The advent of PC adoption triggered the development of new coding, transmission, and presentation methodo...

The popularity of smartphones, virtual reality headsets, and head-mounted devices is fomenting immersive applications that employ realistic representations of the real world. Among these, Point Cloud (PC) contents have recently gained prominence in academia and industry. However, there is some consensus that PC objective quality assessment methods...

In a previous work, we proposed a color extension of an existing focal-plane tone-mapping operator (FPTMO) and introduced circuit modifications that led to smaller sensing array area and simpler off-chip white-balance operations. The proposed FPTMO chip was fabricated and its experimental test setup is under development. In the present work, we sys...

The proliferation of devices such as mobile phones, virtual reality headsets, and head-mounted displays has increased the popularity of immersive applications that deliver realistic representations of the real world. Among the technologies that enable such applications, the point cloud (PC) technology seems to be one of the most mature alternatives...

The topics of visual and audio quality assessment (QA) have been widely researched for decades, yet nearly all of this prior work has focused only on single-mode visual or audio signals. However, visual signals rarely are presented without accompanying audio, including heavy-bandwidth video streaming applications. Moreover, the distortions that may...

Compressive sensing (CS) allows for the reconstruction of sparse signals based on measurements acquired at sub-Nyquist sampling rates. Amongst the common CS methods, total variation (TV) minimization is a common approach used to reconstruct images that are approximately piece-wise constant. The discrete gradient operation in TV can be described as...

The development of audio-visual quality assessment models poses a number of challenges in order to obtain accurate predictions. One of these challenges is the modelling of the complex interaction that audio and visual stimuli have and how this interaction is interpreted by human users. The No-Reference Audio-Visual Quality Metric Based on a Deep Au...

In this paper we present the UnB-AV database, which is a database of audio-visual sequences and quality scores aimed at multimedia quality research. The database contains a total of 140 source content, with a diverse semantic content, both in terms of the video and audio components. It also contains 2,320 test sequences with audio and video degrada...

The development of models for quality prediction of both audio and video signals is a fairly mature field. But, although several multimodal models have been proposed, the area of audio-visual quality prediction is still an emerging area. In fact, despite the reasonable performance obtained by combination and parametric metrics, currently there is n...

In this work, we present a psychophysical study, in which, we analyzed the perceptual quality of images enhanced with several types of enhancement algorithms, including color, sharpness, histogram, and contrast enhancements. To estimate and compare the qualities of enhanced images, we performed a psychophysical experiment with 35 source images, obt...

In the last decade, several aspects of the 3D video technology have been improved, including the 3D content production, distribution, and display. Still, the level of acceptability and popularity of 3D video applications are strongly correlated to the user Quality of Experience (QoE). Since research in this area depends heavily on data acquired in...

The pervasiveness of digital devices like mobile phones, tablets, and personal computers established the presence of image contents as an essential media in several communication applications. In this scenario, the quality of the displayed images is directly correlated with the sense of communication excellence experienced by the users of these app...

A popularização de vídeos 360º trouxe consigo desafios significativos para sua transmissão eficiente via Dynamic Adaptive Streaming over HTTP (DASH) pela Internet, baseada na técnica de ladrilhamento ("tiling") e segmentação temporal do vídeo em diferentes qualidades. Em particular, as exigências significativas de largura de banda e tempo exíguo pa...

This article has in context the proposition of a discipline of Problem-Based Learning (PBL) in which it seeks to achieve soft skills competencies, while technical content is transmitted in the area of product engineering. Through a bibliometric research This analysis seeks to map the studies that encompass the main concepts around the theme: perfor...

This article presents the school of entrepreneurs at the University of Brasilia and emphasizes its importance in the academic training of students, especially those majoring in engineering. This school is a program within the Technological Development Support Center, which is responsible for the developing the University's innovation policy and dis...