16 research outputs found
Scalable virtual viewpoint image synthesis for multiple camera environments
One of the main aims of emerging audio-visual (AV) applications is to provide interactive navigation within a captured event or scene. This paper presents a view synthesis algorithm that provides a scalable and flexible approach to virtual viewpoint synthesis in multiple camera environments. The multi-view synthesis (MVS) process consists of four different phases that are described in detail: surface identification, surface selection, surface boundary blending and surface reconstruction. MVS view synthesis identifies and selects only the best quality surface areas from the set of available reference images, thereby reducing perceptual errors in virtual view reconstruction. The approach is camera setup independent and scalable as virtual views can be created given 1 to N of the available video inputs. Thus, MVS provides interactive AV applications with a means to handle scenarios where camera inputs increase or decrease over time
Multiple image view synthesis for free viewpoint video applications
Interactive audio-visual (AV) applications such as free viewpoint video (FVV) aim to enable unrestricted spatio-temporal navigation within multiple camera environments. Current virtual viewpoint view synthesis solutions for FVV are either purely image-based implying large information redundancy; or involve reconstructing complex 3D models of the scene. In this paper we present a new multiple image view synthesis algorithm that only requires camera parameters and disparity maps. The multi-view synthesis (MVS) approach can be used in any multi-camera environment and is scalable as virtual views can be created given 1 to N of the available video inputs, providing a means to gracefully handle scenarios where camera inputs decrease or increase over time. The algorithm identifies and selects only the best quality surface areas from available reference images, thereby reducing perceptual errors in virtual view reconstruction. Experimental results are presented and verified using both objective (PSNR) and subjective comparisons
Zur QualitÀtsbeurteilung von 3D-Videoobjekten
This thesis is focussed on the quality assessment of natural three-dimensional
video objects. This novel kind of media objects allows watching a natural object
(e. g. an actor) from different viewpoints, ideally from every arbitrary
viewpoint. The quality assessment of such objects raises several questions to be
solved. Many customary methods are not suitable for this new purpose. Firstly,
several methods for the subjective and objective quality assessment of
conventional video are investigated and systematized. Moreover, the manifold
methods of generating 3D video objects are analysed. They cover a wide range
from image-based to model-based methods. This analysis makes it possible to
define the term 3D video object and to develop a model of its process. This
model is applicable to all kinds of 3D video objects. In order to assess the
quality of a 3D video object the definition of a reference is necessary. A 3D
video object showing a sufficient quality has to to serve as reference for the
3D video object in evaluation. Furthermore, specific quality aspects of 3D video
objects are pointed out, e. g., occlusions, distortions along epipolar lines,
artifacts caused by compression, and a differing angle of view. Several methods
like hierarchical block matching and a one-dimensional DFT are used to create
mathematical models describing these quality features. There are significant
restrictions for these methods. Naturally, a 3D video object can not be compared
with its reference pixel by pixel. The models describing the quality features
cover dynamic properties, too. They are depending on time as well as on the
changing of the viewpoint. A set of quality parameters is developed using these
mathematical feature models. These quality parameters consider the visual
perception of the quality aspects and impairments. A methodology creating a 3D
video quality metric 3DVQM based on these quality parameters is introduced. The
parameter weights are determined by a successive approximation using extended
subjective quality judgements. Finally, the proposed methodology is carried out
exemplary by assessing a set of test objects. With this, the prediction of the
subjective assessment based on the proposed objective method is evaluated.Die vorliegende Dissertation beschÀftigt sich mit der QualitÀtsbewertung von
natĂŒrlichen dreidimensionalen Videoobjekten. Dieser neuartige Medienobjekttyp
erlaubt die Betrachtung von natĂŒrlichen Objekten (z. B. einer Person) aus
verschiedenen Perspektiven, die im Idealfall frei wÀhlbar sind. ZunÀchst werden
in dieser Arbeit die Verfahren zur objektiven und subjektiven QualitÀtsbewertung
von konventionellem Bewegtbild untersucht und systematisiert. Ebenso werden die
vielfÀltigen Verfahren zur Generierung von 3D-Videoobjekten analysiert. Diese
bilden ein groĂes Spektrum von bild- bis hin zu modellbasierten Verfahren. Auf
der Grundlage dieser Analyse erfolgt eine Begriffsbestimmung und die
Beschreibung eines Modells der 3D-Videoobjektgenerierung, welches fĂŒr sĂ€mtliche
Generierungsverfahren gĂŒltig ist. Um die QualitĂ€t von 3D-Videoobjekten zu
untersuchen, wird zunĂ€chst die Referenzfrage gelöst. Als Referenzen fĂŒr zu
bewertende 3D-Videoobjekte dienen ausreichend gute 3D-Videoobjekte, welche
denselben Inhalt darstellen. Im Weiteren werden die speziellen QualitÀtsaspekte
von 3D-Videoobjekten aufgezeigt, u. a. GröĂenfehler, Okklusionen,
Epipolarverzerrungen, Kompressionsartefakte und Blickwinkelfehler. Verschiedene
Verfahren wie beispielsweise das hierarchische Block-Matching und die
eindimensionale DFT dienen dazu, diese Merkmale mittels mathematischer Modelle
zu beschreiben. Die wichtigste EinschrÀnkung bei der Auswahl und der Anwendung
dieser Methoden ist es, dass a priori kein Bildpunktbezug vorausgesetzt werden
kann. Die Merkmalsmodelle umfassen auch die dynamischen Eigenschaften, welche
sowohl zeit- als auch blickpunktsÀnderungsabhÀngig sein können. Im Anschluss
wird die Entwicklung von 3D-VideoobjektqualitÀtsmerkmalen auf Basis der
mathematischen Merkmalsmodelle beschrieben. Diese QualitÀtsparameter stellen
einen Bezug zur visuellen Wahrnehmung der QualitÀtsaspekte und Störungen dar. Es
wird eine Methodik zur Bildung eines 3D-VideoobjektqualitĂ€tsmaĂes 3DVQM auf
Basis dieser QualitÀtsparameter vorgestellt. Die Bestimmung der
Gewichtungskoeffizienten erfolgt sukzessive mit Hilfe erweiterter subjektiver
Bewertungsverfahren. Zum Schluss wird die vorgeschlagene Methodik exemplarisch
fĂŒr eine Testreihe durchgefĂŒhrt. In der Auswertung werden die Möglichkeiten der
objektiven Bewertung zur PrÀdiktion der subjektiven QualitÀtsbewertung
dargelegt
Electronic Imaging & the Visual Arts. EVA 2015 Florence
Information Technologies of interest for Culture Heritage are presented: multimedia systems, data-bases, data protection, access to digital content, Virtual Galleries. Particular reference is reserved to digital images (Electronic Imaging & the Visual Arts), regarding Cultural Institutions (Museums, Libraries, Palace â Monuments, Archaeological Sites). The International Conference includes the following Sessions: Strategic Issues; New Technologies & Applications; New 2D-3D Technical Developments & Applications; Virtual Galleries â Museums and Related Initiatives; Access to the Culture Information. Two Workshops regard: International Cooperation; Innovation and Enterprise
QualitĂ€tstaxonomie fĂŒr skalierbare Algorithmen von Free Viewpoint Video Objekten
Diese Dissertation beabsichtigt einen Beitrag zur QualitĂ€tsbeurteilung von Algorithmen fĂŒr Bildanalyse und Bildsynthese im Anwendungskontext Videokommunikationssysteme zu leisten. In der vorliegenden Arbeit werden Möglichkeiten und Hindernisse der nutzerzentrierten Definition von subjektiver QualitĂ€tswahrnehmung in diesem speziellen Anwendungsfall untersucht. QualitĂ€tsbeurteilung von aufkommender Visualisierungs-Technologie und neuen Verfahren zur Erzeugung einer dreidimensionalen ReprĂ€sentation unter der Nutzung von Bildinformation zweier Kameras fĂŒr Videokommunikationssysteme wurde bisher noch nicht umfangreich behandelt und passende AnsĂ€tze dazu fehlen. Die Herausforderungen sind es qualitĂ€tsbeeinflussende Faktoren zu definieren, passende MaĂe zu formulieren, sowie die QualitĂ€tsevaluierung mit den Erstellungsalgorithmen, welche noch in Entwicklung sind, zu verbinden. Der Vorteil der Verlinkung von QualitĂ€tswahrnehmung und ServicequalitĂ€t ist die UnterstĂŒtzung der technischen Realisierungsprozesse hinsichtlich ihrer AnpassungsfĂ€higkeit (z.B. an das vom Nutzer verwendete System) und Skalierbarkeit (z.B. Beachtung eines Aufwands- oder Ressourcenlimits) unter BerĂŒcksichtigung des Endnutzers und dessen QualitĂ€tsanforderungen. Die vorliegende Arbeit beschreibt den theoretischen Hintergrund und einen Vorschlag fĂŒr eine QualitĂ€tstaxonomie als verlinkendes Modell. Diese Arbeit beinhaltet eine Beschreibung des Projektes Skalalgo3d, welches den Rahmen der Anwendung darstellt. PrĂ€sentierte Ergebnisse bestehen aus einer systematischen Definition von qualitĂ€tsbeeinflussenden Faktoren inklusive eines Forschungsrahmens und EvaluierungsaktivitĂ€ten die mehr als 350 Testteilnehmer inkludieren, sowie daraus heraus definierte QualitĂ€tsmerkmale der evaluierten QualitĂ€t der visuellen ReprĂ€sentation fĂŒr Videokommunikationsanwendungen. Ein darauf basierendes Modell um diese Ergebnisse mit den technischen Erstellungsschritten zu verlinken wird zum Schluss anhand eines formalisierten QualitĂ€tsmaĂes prĂ€sentiert. Ein Flussdiagramm und ein Richtungsfeld zur grafischen AnnĂ€herung an eine differenzierbare Funktion möglicher ZusammenhĂ€nge werden daraufhin fĂŒr weitere Untersuchungen vorgeschlagen.The thesis intends to make a contribution to the quality assessment of free viewpoint video objects within the context of video communication systems. The current work analyzes opportunities and obstacles, focusing on users' subjective quality of experience in this special case. Quality estimation of emerging free viewpoint video object technology in video communication has not yet been assessed and adequate approaches are missing. The challenges are to define factors that influence quality, to formulate an adequate measure of quality, and to link the quality of experience to the technical realization within an undefined and ever-changing technical realization process. There are two advantages of interlinking the quality of experience with the quality of service: First, it can benefit the technical realization process, in order to allow adaptability (e.g., based on systems used by the end users). Second, it provides an opportunity to support scalability in a user-centered way, e.g., based on a cost or resources limitation. The thesis outlines the theoretical background and introduces a user-centered quality taxonomy in the form of an interlinking model. A description of the related project Skalalgo3d is included, which offered a framework for application. The outlined results consist of a systematic definition of factors that influence quality, including a research framework, and evaluation activities involving more than 350 participants. The thesis includes the presentation of quality features, defined by evaluations of free viewpoint video object quality, for video communication application. Based on these quality features, a model that links these results with the technical creation process, including a formalized quality measure, is presented. Based on this, a flow chart and slope field are proposed. These intend the visualization of these potential relationships and may work as a starting point for further investigations thereon and to differentiate relations in form of functions
Electronic Imaging & the Visual Arts. EVA 2014 Florence
Information Technologies of interest for Culture Heritage are presented: multimedia systems, data-bases, data protection, access to digital content, Virtual Galleries. Particular reference is reserved to digital images (Electronic Imaging & the Visual Arts), regarding Cultural Institutions (Museums, Libraries, Palace - Monuments, Archaeological Sites). The International Conference includes the following Sessions: Strategic Issues; EC Projects and Related Networks & Initiatives; 2D - 3D Technologies and Applications; Virtual Galleries - Museums and Related Initiatives; Access to the Culture Information. Three Workshops regard: International Cooperation; Innovation and Enterprise; e.Culture Cloud
Electronic Imaging & the Visual Arts. EVA 2018 Florence
The Publication is following the yearly Editions of EVA FLORENCE. The State of Art is presented regarding the Application of Technologies (in particular of digital type) to Cultural Heritage. The more recent results of the Researches in the considered Area are presented. Information Technologies of interest for Culture Heritage are presented: multimedia systems, data-bases, data protection, access to digital content, Virtual Galleries. Particular reference is reserved to digital images (Electronic Imaging & the Visual Arts), regarding Cultural Institutions (Museums, Libraries, Palace - Monuments, Archaeological Sites). The International Conference includes the following Sessions: Strategic Issues; New Sciences and Culture Developments and Applications; New Technical Developments & Applications; Museums - Virtual Galleries and Related Initiatives; Art and Humanities Ecosystem & Applications; Access to the Culture Information. Two Workshops regard: Innovation and Enterprise; the Cloud Systems connected to the Culture (eCulture Cloud) in the Smart Cities context. The more recent results of the Researches at national and international are reported in the Area of Technologies and Culture Heritage, also with experimental demonstrations of developed Activities
Electronic Imaging & the Visual Arts. EVA 2012 Florence
The key aim of this Event is to provide a forum for the user, supplier and scientific research communities to meet and exchange experiences, ideas and plans in the wide area of Culture & Technology. Participants receive up to date news on new EC and international arts computing & telecommunications initiatives as well as on Projects in the visual arts field, in archaeology and history. Working Groups and new Projects are promoted. Scientific and technical demonstrations are presented