A Comunicação Digital e a Interdisciplinaridade na Produção de Conteúdo Interativo

RESUMOO advento do Ginga-NCL, padrão do Sistema Brasileiro de Televisão Digital Terrestre, no campo da comunicação digital representa um desafio paradigmático aos produtores de conte´do nas emissoras de televisão. Este artigo apresenta a experiência de desenvolvimento de uma narrativa audiovisual interativa, o Roteiro do Dia, a partir da prática interdisciplinar entre as ciências da comunicação e da computação, e implementa algumas das principais características de interatividade em TV Digital.Palavras-chave: TV digital; Ginga-NCL; conteúdo interativo. RESUMENLa aparición del Ginga-NCL, patrón del Sistema Brasileño de Televisión Digital Terrestre, en el ámbito de la comunicación digital representa un reto paradigmático para los productores de contenido en estaciones de televisión. Este articulo presenta la experiencia del desarrollo de una narrativa audiovisual interactiva, el Roteiro do Dia, desde la plática interdisciplinaria entre las ciencias de comunicación y computación, y implementa algunas de las principales características de la interactividad en TV Digital.Palabras clave:TV digital; Ginga-NCL; contenido interactivo. ABSTRACTThe coming of Ginga-NCL, the Brazilian Digital Terrestrial Television standard, in digital communication field represents a paradigmatic challenge for broadcasting content producers. This paper shows the experience of developing an interactive audiovisual narrative, Roteiro do Dia, from an interdisciplinary practice between communication and computer sciences, and uses some main features of interactivity in Digital TV.Keywords: Digital TV; Ginga-NCL; interactive content

Visual Distortions in 360-degree Videos

Omnidirectional (or 360-degree) images and videos are emergent signals in many areas such as robotics and virtual/augmented reality. In particular, for virtual reality, they allow an immersive experience in which the user is provided with a 360-degree field of view and can navigate throughout a scene, e.g., through the use of Head Mounted Displays. Since it represents the full 360-degree field of view from one point of the scene, omnidirectional content is naturally represented as spherical visual signals. Current approaches for capturing, processing, delivering, and displaying 360-degree content, however, present many open technical challenges and introduce several types of distortions in these visual signals. Some of the distortions are specific to the nature of 360-degree images, and often different from those encountered in the classical image communication framework. This paper provides a first comprehensive review of the most common visual distortions that alter 360-degree signals undergoing state of the art processing in common applications. While their impact on viewers' visual perception and on the immersive experience at large is still unknown ---thus, it stays an open research topic--- this review serves the purpose of identifying the main causes of visual distortions in the end-to-end 360-degree content distribution pipeline. It is essential as a basis for benchmarking different processing techniques, allowing the effective design of new algorithms and applications. It is also necessary to the deployment of proper psychovisual studies to characterise the human perception of these new images in interactive and immersive applications

Fortalecer as atividades de informação e vigilância epidemiológica é essencial e urgente para reduzir a força de transmissão do SARS-CoV-2

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Graph-Based Detection of Seams In 360-Degree Images

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) projection, and undergoes lossy compression. The proposed algorithm exploits a graph-based representation to account for the actual sampling density of the 360-degree signal in the native spherical domain. The CM image is considered as a signal lying on a graph defined on the spherical surface. The spectra of the processed and the original signals, computed by applying the Graph Fourier Transform, are compared to detect the seams. To test our method a dataset of compressed CM 360-degree images, annotated by experts, has been created. The performance of the proposed algorithm is compared to those achieved by baseline metrics, as well as to the same approach based on spectral comparison but ignoring the spherical nature of the signal. The experimental results show that the proposed method has the best performance and can successfully detect up to approximately 90% of visible seams on our dataset

Increasing reuse in learning objects authoring: a case study with the Cacuria tool

Artifacts and best practices reuse as a way of improving educational resources and easing and speeding up the authoring process have been an important theme since the earliest research efforts on Learning Objects (LOs). In such a context, authoring tools that allow teachers and tutors to create educational content without the need for advanced programming knowledge play an essential role. This paper presents the evolution of Cacuria -an authoring tool that supports the creation of interactive multimedia educational content for the Web and digital TV- towards improved support for LOs reuse and analyzes the impact of the proposals as perceived by the users of the tool. The proposed evolution is based on previous work on reuse requirements and best practices on authoring LOs, which resulted in the inclusion of three new features on the tool: Layouts, Widgets, and Application Templates. Through these new resources, authors can build LOs by reusing resources created by other authors and reuse good practices, e.g., through previously validated pedagogical practices. The added functionalities were evaluated in a qualitative study with 11 teachers/tutors. The results of the study indicate that the participants believe that the new functionalities improved the creation of reusable LOs both in the creative aspect and in the reduction of the total development time

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

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 distortions when consumed through HMDs, we perform an exploratory task-based subjective study in which we have asked subjects to define the first noticeable difference and break-in-presence points when incrementally adding specific compression artifacts. The results of our study: give insights on the range of allowed visual distortions for 360-degree content; show that the added visual distortions are more tolerable in mono than in stereoscopic 3D; and identify issues with current 360-degree objective quality metrics