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Publications

Publications by António Coelho

2016

Video Annotation for Immersive Journalism using Masking Techniques

Authors
Meira, J; Marques, J; Jacob, J; Nobrega, R; Rodrigues, R; Coelho, A; Augusto de Sousa, AA;

Publication
2016 23RD PORTUGUESE MEETING ON COMPUTER GRAPHICS AND INTERACTION (EPCGI)

Abstract
This paper proposes an interactive annotation technique for 360 degrees videos that allows the use of traditional video editing techniques to add content to immersive videos. Using the case study of immersive journalism the main objective is to diminish the entry barrier for annotating 360 degrees video pieces, by providing a different annotation paradigm and a set of tools for annotation. The spread of virtual reality systems and immersive content has been growing substantially due to technological progress and cost reductions in equipment and software. From all the technologies employed in virtual reality systems, 360 degrees video is one that currently presents unique conditions to be widely used by various industries -especially for communication purposes. From the various areas that can benefit from the usage of virtual reality systems, the communication field is one that requires innovation in the way that narratives are built, especially in virtual reality systems. In the case of immersive journalism, 360 degrees video technology is currently one of the most used mediums by several media outlets. This kind of news content, whose innovative role should be highlighted, is still being studied in the field of journalism, needing a clearly defined set of rules and good practises. In order to improve the introduction of virtual elements in the 360 degrees videos this paper proposes a set of annotation paradigms for 1) Media information display and 2) Narrative and attention focusing. In this paper we present a list of possible techniques that solve the problem of immersive annotation, as well as a description of a prototype that was developed to test these concepts. The prototype implements an annotation technique based on masked videos and the extension of standard subtitle file formats. Finally a fast-track user study was developed to evaluate the acceptance of the visualisation techniques and to refine the set of tools.

2016

Layered shape grammars for procedural modelling of buildings

Authors
Jesus, D; Coelho, A; Sousa, AA;

Publication
VISUAL COMPUTER

Abstract
The effort of creating virtual city environments is reduced using procedural modelling techniques. However, these typically use split-based approaches which can impose limitations on the final geometry, usually enforcing a grid-like structure and require complex geometry to be imported. Layered shape grammars can increase the variability of procedural buildings, while the vectorial definition of shapes introduces the possibility of creating complex shapes that seamlessly blend into the model. We evaluate the contributions with a modelling example and a comparison with split-based procedural modelling techniques. Results show that layers allow more flexibility than split-based techniques in creating variations. Vectorially defined shapes are a step forward in shape grammar expressiveness.

2013

Real-time Augmented Reality Demo Platform for Exploring Consumer Emotional Responses with Shopping Applications

Authors
Stoyanova, J; Gonçalves, R; Brito, PQ; Coelho, A;

Publication
Int. J. Online Biomed. Eng.

Abstract
The present-day revival of Augmented reality (AR) technology has led to its vast expansion in various applications. In marketing, the hunt for more inventive and intriguing approaches for immersive consumer experiences has endorsed the implementation of AR in multiple brand advertising campaigns, specifically for improved product display. The engaging potential of this technology is established in the fusion between computer-generated data and the physical world as seen by the user, where 3D registration and real time interaction are inseparable parts of this system. Alternatively, impressions from user experiences serve as a principal instrument in the evaluation process of the effectiveness of interactive systems. In order to get deeper insight into consumers' reflections from a real-time AR shopping experience, we present a demo platform for the purchase of sneakers, focusing on users' behavior and more precisely on their perceptions, emotions, personal preferences before, during and after use of the platform. To fully evaluate and compare consumer experiences with the main AR platform, two other shopping systems were designed: a marker-based and a static one. Consecutively, we aim at defining a system of metrics for measuring shopping experiences with AR, as well as at establishing a ground base for subsequent marketing research in the field. Motivated by the large application of the technology and aiming at understanding the impact of AR on consumer psychology, the application will assist in exploring the antecedents of consumer purchase intentions.

2013

Real-time Augmented Reality shopping platform for studying consumer cognitive experiences

Authors
Stoyanova, J; Goncalves, R; Coelho, A; Brito, P;

Publication
2013 2ND EXPERIMENT@ INTERNATIONAL CONFERENCE (EXP.AT'13)

Abstract
Augmented Reality (AR) is a technology which produces a synthesis between a computer-generated data and the physical world of a viewer while establishing 3D registration and real time interaction. Among the wide range of application of AR, its use in advertising shopping experiences has recently been embraced by advertisers due to its novelty and engaging potential. Part of a wider research aiming at understanding the impact of AR on consumer psychology, this paper presents a demo platform application developed for a real-time shopping experience for shoes and attempts to define a ground base for posterior marketing research in the field. In order to fully evaluate consumer experiences and compare with the main AR platform two other shopping applications were designed: a marker-based and a static one. The platform will assist in exploring the antecedents of consumer purchase intention and in defining metrics for measuring shopping experiences with AR.

2015

Relationship Between Game Categories and Skills Development: Contributions for Serious Game Design

Authors
Baptista, R; Coelho, A; de Carvalho, CV;

Publication
PROCEEDINGS OF THE 9TH EUROPEAN CONFERENCE ON GAMES BASED LEARNING (ECGBL 2015)

Abstract
Recently, Serious Games (SG) achieved a recognized position as a learning tool in several contexts. SG provide constructive learning environments in which errors can be made without real life penalties and where students get instant feedback from their actions when facing challenges. These challenges should be in accordance with the intended learning goals and they should adapt and/or be repeated according to the learner's level. This aspect is decisive in the acquisition of knowledge, experience and professional skills through the simulation of different situations and contexts. The effectiveness of competences' training is directly related to the success in their acquisition but, above all, it is related to the ability to apply them to successfully perform a given task. However, an optimal game design methodology for competence training is yet to be created. This article presents a study that identifies the most appropriate game categories to develop specific skills and competences. It considers a taxonomy with eight game categories (Action, Strategy, Playing, Sports, Management Simulation, Adventure, Puzzle and Quiz) that were matched with the Education Competences and Educational Competency Wheel. Analysing 116 serious games allowed identifying which categories were more efficient in the training of a specific competence and therefore should be reused in the same scope.

2015

Procedural Content Graphs for Urban Modeling

Authors
Silva, PB; Eisemann, E; Bidarra, R; Coelho, A;

Publication
INTERNATIONAL JOURNAL OF COMPUTER GAMES TECHNOLOGY

Abstract
Massive procedural content creation, for example, for virtual urban environments, is a difficult, yet important challenge. While shape grammars are a popular example of effectiveness in architectural modeling, they have clear limitations regarding readability, manageability, and expressive power when addressing a variety of complex structural designs. Moreover, shape grammars aim at geometry specification and do not facilitate integration with other types of content, such as textures or light sources, which could rather accompany the generation process. We present procedural content graphs, a graph-based solution for procedural generation that addresses all these issues in a visual, flexible, and more expressive manner. Besides integrating handling of diverse types of content, this approach introduces collective entity manipulation as lists, seamlessly providing features such as advanced filtering, grouping, merging, ordering, and aggregation, essentially unavailable in shape grammars. Hereby, separated entities can be easily merged or just analyzed together in order to perform a variety of context-based decisions and operations. The advantages of this approach are illustrated via examples of tasks that are either very cumbersome or simply impossible to express with previous grammar approaches.

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