Fehlerkaschierte Bildbasierte Darstellungsverfahren

Creating photo-realistic images has been one of the major goals in computer graphics since its early days. Instead of modeling the complexity of nature with standard modeling tools, image-based approaches aim at exploiting real-world footage directly,as they are photo-realistic by definition. A drawback of these approaches has always been that the composition or combination of different sources is a non-trivial task, often resulting in annoying visible artifacts. In this thesis we focus on different techniques to diminish visible artifacts when combining multiple images in a common image domain. The results are either novel images, when dealing with the composition task of multiple images, or novel video sequences rendered in real-time, when dealing with video footage from multiple cameras.Fotorealismus ist seit jeher eines der großen Ziele in der Computergrafik. Anstatt die Komplexität der Natur mit standardisierten Modellierungswerkzeugen nachzubauen, gehen bildbasierte Ansätze den umgekehrten Weg und verwenden reale Bildaufnahmen zur Modellierung, da diese bereits per Definition fotorealistisch sind. Ein Nachteil dieser Variante ist jedoch, dass die Komposition oder Kombination mehrerer Quellbilder eine nichttriviale Aufgabe darstellt und häufig unangenehm auffallende Artefakte im erzeugten Bild nach sich zieht. In dieser Dissertation werden verschiedene Ansätze verfolgt, um Artefakte zu verhindern oder abzuschwächen, welche durch die Komposition oder Kombination mehrerer Bilder in einer gemeinsamen Bilddomäne entstehen. Im Ergebnis liefern die vorgestellten Verfahren neue Bilder oder neue Ansichten einer Bildsammlung oder Videosequenz, je nachdem, ob die jeweilige Aufgabe die Komposition mehrerer Bilder ist oder die Kombination mehrerer Videos verschiedener Kameras darstellt

Form follows function: pragmatic controlled trials (PCTs) have to answer different questions and require different designs than randomized controlled trials (RCTs).

Aim Rising concern for demonstrated real world comparative effectiveness has heightened interest in “pragmatic trials” design. Pragmatic trials investigate whether the efficacy, presumed or found in explanatory trials under ideal conditions, can also be detected under real world conditions, i.e. effectiveness. It is also recognized that ‘real world’ effects which are usually addressed in public health research gain growing interest in confirming the ‘road capability’ of results obtained under ideal study conditions. This paper demonstrates that studies under ideal or real world conditions use different methods, generate different information and cannot replace each other. Subjects and methods The PCT design meets four requirements of public health and of effectiveness research. It includes all individuals who presented with the selected condition. It classifies the included individuals according to baseline risks. It enables plausibility controls. Finally, it compares the outcomes resulting from specified and notspecified interventions or treatments. Proposal We propose a pragmatic controlled trial (PCT) design in which patient preference and other co-factors crucial in determining the actual effectiveness of interventional options will not be neutralized by concealed randomization and blinding. This design is applicable to record the selected interventions and generated outcomes in day-to-day health care and is capable of incorporating preference and other participative factors into assessment of effectiveness. Conclusions The PCT design is useful for public health research, e.g. the effectiveness of interventions to change smoking habits or to prevent death frombreast cancer, as well as for comparative effectiveness research where it will supplement the traditional randomized controlled trial (RCT)

Exploring Personality and Readiness to Change in Patients With Substance Use Disorders With and Without ADHD

Objective: To explore personality and readiness to change among substance use disorders (SUD) patients with and without ADHD. Method: SUD + ADHD versus SUD − ADHD patients consecutively entering treatment between 2010 and 2012 were compared concerning personality (Temperament and Character Inventory) and readiness to change (Stages of Change Readiness and Treatment Eagerness Scale). Results: Among 103 SUD patients (76 men, age M = 43.3, SD = 11.1), 16 (15.5%) were diagnosed with ADHD. SUD + ADHD patients reported significantly elevated eagerness to effort (p = .008) compared with SUD − ADHD patients, who reported significantly elevated fear of uncertainty (p Conclusion: The distinct characteristics found in SUD + ADHD and SUD − ADHD patients underline the need for differentiated treatment interventions.</p

Filtered Blending und Floating Textures: Projektive Texturierung mit multiplen Bildern ohne Geisterartefakte

Whenever approximate 3D geometry is projectively texture-mapped from different directions simultaneously, annoyingly visible aliasing artifacts are the result. To prevent such ghosting in projective texturing and image-based rendering, we propose two different GPU-based rendering strategies: filtered blending and floating textures. Either approach is able to cope with imprecise 3D geometry as well as inexact camera calibration. Ghosting artifacts are effectively eliminated at real-time rendering frame rates on standard graphics hardware. With the proposed rendering techniques, better-quality rendering results are obtained from fewer images, coarser 3D geometry, and less accurately calibrated images.Jedesmal wenn eine grob approximierte Geometrie eines Objektes simultan, projektiv texturiert wird aus verschiedenen Ansichten, treten häßliche Aliasing-Artefakte auf. Um diese Geisterartefakte bei projektiver Texturierung und bildbasiertem Rendering zu verhindern, schlagen wir zwei verschiedene, GPU-basierte Renderingstrategien vor: Filtered Blending und Floating Textures. Beide beheben die Probleme ungenauer 3D Geometrie und inexakter Kamerakalibrierung. Geisterartefakte werden in Echtzeit effektiv entfernt unter Verwendung von standard Graphikhardware. Mittels der vorgeschlagenen Renderingtechniken erreichen wir eine deutlich höhere Qualität der Ausgabebilder, bei gleichzeitig weniger Bildern, gröberer 3D Geometrie und weniger akkurat kalibrierten Bildern

ZIPMAPS: Zoom-in-bestimmte-Bereiche Texturen

In this technical report, we propose a method for rendering highly detailed close-up views of arbitrary textured surfaces. To augment the texture map locally with high-resolution information, we describe how to automatically, seamlessly merge unregistered images of different scales. Our hierarchical texture representation can easily be rendered in real-time, enabling zooming into specific texture regions to almost arbitrary magnification. Our method is useful wherever close-up renderings of specific regions shall be possible, without the need for excessively large texture maps.Wir präsentieren eine neue Methode um sehr detailierte Ansichten von beliebig texturierten Oberflächen zu generieren. Wir beschreiben wie man automatisch und ohne sichtbare Nähte unregistrierte Bilder unterschiedlicher Skalen miteinander kombiniert um lokal hochaufgelöste Detailinformationen hinzuzufügen. Unsere hierarchische Texturrepräsentation kann sehr einfach und in Echtzeit gerendert werden und erlaubt somit den Zoom in bestimmte Textureregionen mit nahezu beliebiger Vergrößerung. Unsere Methode ist immer dann sinnvoll, wenn Vergrößerungen entsprechender Bereiche notwendig sind, ohne dass man entsprechend große Texturen speichern möchte

Predictors of rate of change for children and youth with emotional disorders: a naturalistic observational study

Published version. Source at http://dx.doi.org/10.1186/s13034-016-0098-3 Background: To examine demographic and clinical characteristics as potential predictors of change for children and youth with emotional disorders treated at two child and adolescent mental health outpatient services (CAMHS) in Norway. Methods: The study was of naturalistic observational type with “treatment as usual” (TAU). The sample consisted of 84 children and youth with emotional disorders. The Health of the Nation Outcome Scale (HONOSCA), and the Children’s Global Assessment Scale (CGAS) were administered at intake (T0), during the assessment (T1) and approximately six months after assessment (T2). Change was analysed by means of the linear mixed models procedure. Results: For the HONOSCA total score, youths with a diagnosis of depression had statistically higher symptom severity levels at baseline and significantly lower change rates as compared to youths with an anxiety disorder. Conclusions: The current study adds to the limited knowledge of predictors of rate of change for children and adolescents with emotional disorders treated within CAMHS. Our results point to a special need to improve clinical care for depressed children and adolescents. Important limitations comprising the external validity of the study concern missing data, a small study sample, and lack of information regarding the content and extent of the service provided

Uptake and adherence of a self-directed internet-based mental health intervention with tailored e-mail reminders in senior high schools in Norway

Background Internet-based cognitive behavioural therapy (ICBT) is a promising approach to the prevention and reduction of depressive symptoms among adolescents. This study aimed to evaluate the feasibility and efficacy of disseminating a self-directed internet-based mental health intervention (MoodGYM) in senior high schools. It also sought to investigate possible effects of tailored and weekly e-mail reminders on initial uptake and adherence to the intervention. Method A baseline survey was conducted in four senior high schools in two Norwegian municipalities (n = 1337). 52.8% (707/1337) of the students consented to further participation in the trial and were randomly allocated to one of three MoodGYM intervention groups (tailored weekly e-mail reminder (n = 175), standardized weekly e-mail reminder (n = 176 ) or no e-mail reminder (n = 175)) or a waitlist control group (n = 180). We tested for effects of the intervention on depression and self-esteem using multivariate analysis of variance, effects of tailored e-mail and self-reported current need of help on initial uptake of the intervention using logistic regression and the effect of weekly e-mails on adherence using ordinal regression. Results There was substantial non-participation from the intervention, with only 8.5% (45/527) participants logging on to MoodGYM, and few proceeding beyond the first part of the programme. No significant effect on depression or self-esteem was found among the sample as a whole or among participants with elevated depression scores at baseline. Having a higher average grade in senior high school predicted initial uptake of the intervention, but tailored e-mail and self-reported current need of help did not. Weekly e-mail prompts did not predict adherence. The main reasons for non-use reported were lack of time/forgetting about it and doubt about the usefulness of the program. Conclusion Overall, disseminating a self-directed internet-based intervention to a school population proved difficult despite steps taken to reduce barriers in terms of tailoring feedback and dispatching weekly e-mail reminders. Providing mental health interventions within the school environment is likely to ensure better uptake among senior high school students, but there is a need to effectively communicate that such programmes can be helpful

Implicit Object Space Partitioning: The No-Memory BVH

We present a new ray tracing algorithm that requires no explicit acceleration data structure and therefore no memory. It is represented in a completely implicit way by triangle reordering. This new implicit data structure is simple to build, efficient to traverse and has a fast total time to image. The implicit acceleration data structure must be constructed only once and can be reused for arbitrary numbers of rays or ray batches without the need to rebuild the hierarchy. Due to the fast build times it is very well suitable for dynamic and animated scenes. We compare it to classic acceleration data structures, like a Bounding Volume Hierarchy, and analyze its effciency

Structure-Aware Image Compositing

The classic task of image compositing is complicated by the fact that the source and target images need to be carefully aligned and adjusted. Otherwise, it is not possible to achieve convincing results. Visual artifacts are caused by image intensity mismatch, image distortion or structure misalignment even if the images have been globally aligned. In this paper we extend classic Poisson blending by a constrained structure deformation and propagation method. This approach can solve the above-mentioned problems and proves useful for a variety of applications, e.g. in de-ghosting of mosaic images, classic image compositing or other applications such as superresolution from image databases. Our method is based on the following basic steps. First, an optimal partitioning boundary is computed between the input images. Then, features along this boundary are robustly aligned and deformation vectors are computed. Starting at these features, salient edges are traced and aligned, serving as additional constraints for the smooth deformation field, which is propagated robustly and smoothly into the interior of the target image. If very different images are to be stitched, we propose to base the deformation constraints on the curvature of the salient edges for C1-continuity of the structures between the images. We present results that show the robustness of our method on a number of image stitching and compositing tasks.Bildkompositionen werden oft dadurch erschwert, dass die zwei zusammenzufügenden Bilder vorsichtig und genau justiert und angepasst werden müssen. Andernfalls können keine überzeugenden Ergebnisse erreicht werden. Visuelle Artefakte können durch unterschiedliche Intensitäten, Verzerrungen oder strukturelle Missanpassungen entstehen, selbst wenn die Bilder global ausgerichtet wurden. In diesem Report wird das klassische Poisson Blending erweitert durch eine gezielte Strukturdeformation und Propagierung derselben. Dieser Ansatz löst die oben genannten Probleme und ist sinnvoll einsetzbar in einer Reihe von Anwendungen wie Mosaikbilder, Bildkompositionen, oder sogar Super-Resolution durch Bilddatenbanken. Die Methode basiert auf folgenden Schritten: Zunächst wir eine optimale Partitionierung berechnet zwischen den Eingabebildern, dann werden die wichtigen Features entlang dieser Grenze in Einklang gebracht und entsprechende Deformationsvektoren berechnet. Ausgehend von diesen Features werden die auffälligen Kanten weiterverfolgt und in Einklang gebracht. Diese Deformationen werden dann über das gesamte Bild ausgebreitet. Wenn die Bilder stark unterschiedlich sind schlagen wir in diesem Report vor die Verformung auf Basis der Krümmung der Kanten zu durchzuführen. Es werden Ergebnisse präsentiert, die die Robustheit der Methode zeigen