Computer Graphics
TU Braunschweig

Events


Talk Scene-Space Video Processing

17.05.2019 13:00
Informationzentrum, Seminarraum G30

Speaker(s): Felix Klose

quuxLogic Solutions GmbH

Nearly all image based video processing methods require correspondences to be established in between input images. Finding image correspondences is an area of active research for many years, and is known to be a notoriously difficult problem, due to its ill-posed nature and large number of unknowns. If the input data is not only a few images, but single or multiple video streams, the amount of data to be processed poses an additional challenge. This thesis provides a insight into commonly applied constraints to correspondence estimation in 2D, 3D and 4D and the applications that become possible from using the different data modalities. It is shown how free-viewpoint stereoscopic 3D renderings of multi-view recordings can be generated by purely using 2D correspondences. To accomplish this in the required high output quality, a simple interaction paradigm is introduced, that allows users to correct correspondences where the automatic results are not yet of sufficient quality. An approach to compute full quasi-dense scene-flow for short time intervals is presented. This work then shows how new applications become possible, when the inaccuracies in scene estimation are leveraged and the full redundancy of the available visual data is exploited. And highlights the performance implications of using the large amounts of available data.

Talk Tell Me How You Look and I'll Tell You How You Move

26.04.2019 09:15
Tampere University, Tampere, Finland

Speaker(s): Thiemo Alldieck

Talk at CIVIT Tech Day: Motion Deconstructed

[Video]

Human body shape and motion estimation are two sides of the same coin. To be able to fully understand human motion from monocular imagery, we need to understand the shapes of the tracked subjects, too. In my talk, I will motivate why we need better shapes for better tracking. I will demonstrate how 3D bodies helped us to understand human motion better and where these models find their limits.  If we want to learn rich models of human shape, motion, and dynamics, we require new approaches that learn from ubiquitous data such as plain RGB-images and video. I continue with discussing recent advances in personalized body shape estimation from monocular video, from a few frames, and even from a single image. We developed effective methods to learn detailed avatars without the need for expensive scanning equipment. These methods are easy to use and enable various VR and AR applications. I will conclude my talk by outlining the next challenges in human shape reconstruction and how this potentially affects human motion estimation.

Talk BA-Talk: Exploring high-dimensional data with Parallel Coordinates

15.04.2019 13:00
Informationzentrum, Seminarraum G30

Speaker(s): Waldemar Gorbunov

Talk Data-driven estimation and neuro-physiological assessment of perceived visual quality

12.04.2019 13:00
Informatikzentrum IZ, Seminarraum G30

Speaker(s): Sebastian Bosse

FhG-HHI Berlin

Perceptual quality is a key aspect of modern multimedia systems. Nevertheless, the questions of how to computationally estimate perceived quality, how to incorporate computational models of quality in technical systems and how to reliably assess the true quality as perceived by humans remain answered unsatisfactorily. In my talk I will outline novel neural network-based and end-to-end optimized models for visual quality estimation and show how such models can be used in practice, i.e. for perceptually optimized bit allocation in state-of-the-art video compression schemes. The reliability of these data-driven models rely on the availability of large quality annotated data sets.  For generating such data sets, conventional psychophysical approaches inherently suffer from several crucial drawback. My talk will discuss how neuro-physiological quality assessment may overcome these flaws and pave the way towards reliable assessment of perceptual quality.

 

Talk Teamprojekt-Abschluss: A Look Through Floyd Lawton's Mask

01.04.2019 13:00
Dome (Aufnahmestudio & Visualisierungslabor)

Präsentation der Ergebnisse des studentischen Teamprojekts.

Talk Praktikum-Abschluss: World Builder VR Toolkit Extended

01.04.2019 13:00
Dome (Aufnahmestudio & Visualisierungslabor)

Präsentation der Ergebnisse des studentischen Computergraphik Praktikums.
(Ein Folgeprojekt vom Teamprojekt WS '17/18)

Talk MA-Talk: Human Pose Estimation in Augmented Reality Scenarios

22.03.2019 13:00
Informatikzentrum, Seminarraum G30

Speaker(s): Alexander Meyer

Talk MA-Talk: Evaluation von Visualisierungstechniken unter Nutzung von Eye-Tracking und EEG

01.03.2019 13:00
Informatikzentrum, Seminarraum G30

Speaker(s): Anton Antonenko

Talk BA-Talk: Analyse- und Berechnungsverfahren zur Auswertung eines pixelierten Detektors mit einem Gleitschatten-Filter

15.02.2019 13:00
Seminarraum G30

Speaker(s): Felix Lehner

Talk Computer - Bilder

22.01.2019 19:00
Kunstverein Braunschweig

Speaker(s): Marcus Magnor

Talk Turning Reality into Virtual Reality

30.11.2018 11:00
FhG Heinrich Hertz Institut Berlin

Speaker(s): Marcus Magnor

Current endeavors towards immersive visual entertainment are still almost entirely based on 3D graphics-generated content, limiting application scenarios to virtual worlds only. The reason is that in order to provide for stereo vision and ego-motion parallax, two essential ingredients for genuine visual immersion perception, the scene must be rendered in real-time from arbitrary vantage points. While this can be easily accomplished with 3D graphics via standard GPU rendering, it is not at all straight-forward to do the same from conventional video footage acquired of real-world events. In my talk I will outline avenues of research toward enabling the immersive experience of real-world recordings and how to enhance the immersive viewing experience by taking perceptual issues into account.

Talk MA-Talk: Learning Optical Flow from Long-Exposure Images

23.11.2018 11:00
Seminarraum G30

Speaker(s): Moritz Kappel

Recently, Convolutional Neural Networks (CNNs) have been applied to a wide range of tasks including classification, detection, segmentation
and optical flow. Despite convincing results the overall capability of CNNs depends on the utilized training data for supervised learning. This
is especially restricting for optical flow estimation as obtaining ground truth optical flow is infeasible for the bulk number of real world scenes
required for training. As a consequence approaches for unsupervised learning gained more interest.


In this thesis, a CNN was designed to learn the Optical Flow between two images, consisting of the backward and forward motion for
every pixel. Furthermore, an occlusion moment was learned, at which a pixel becomes visible in the target image. For simplicity only
linear motion was considered, as this is sufficient to approximate more complex motion with small time-steps. Unlike traditional supervised Optical Flow networks, the CNN in this thesis was not trained with ground truth optical flow but with long-exposure images between the two images.

Talk BA-Talk: GPU-basierte Bildverarbeitung zur Analyse neuronaler Aktivität in Zebra fischlarven

05.11.2018 13:00
Seminarraum G30

Speaker(s): Immanuel Becker

Bei der Analyse neuronaler Aktivität von lebenden Zebra schlarven mittels Lichtblattmikroskopie werden Auflösungen erreicht, durch die einzelne Neuronen sichtbar werden. Für jede Aufnahme durch das Mikroskop wird der Fisch schichtweise durchleuchtet, sodass ein 3D Bild seines Kopfes entsteht.
Viele solcher 3D Aufnahmen über die Zeit bilden eine große Datenmenge deren Verarbeitung viel Zeit beansprucht. Das Ziel dieser Arbeit ist, GPU-basierte Beschleunigungen zu präsentieren, die die Ausführungszeit von kritischen Stellen der Verarbeitungsroutine verbessern.

Talk Digital Personality and The Emotional Onion

19.10.2018 13:00
IZ G30

Speaker(s): Susana Castillo

BTU Cottbus

Communication is inherent to life. During our daily life we convey information verbally and nonverbally. We can learn a lot about someone by watching their facial expressions and body language. Used to this kind of interaction with their interlocutors, people tend to personify machines, thus, harnessing these
aspects of non-verbal communication can lend virtual agents greater depth and realism, by giving them the ability to actually produce social information. But, in order to achieve these goals, we require a sound understanding of the relationship between cognition and expressive behavior.

This talk explores the multi-layered nature of communication and introduces an extended traditional word-based methodology to use both actual videos and motion capture data to extract the semantic/cognitive space of facial expressions. These recovered spaces can capture the full range of facial communication and are very suitable for semantic-driven facial animation.

Nevertheless, to provide virtual agents with full human-like communicative capabilities, natural facial expressions are not enough. We would like to impregnate all emotions with coherent deviations from the ’neutral’ emotions that can be perceived as series of personality traits which will result in the classification
of the agent as a particular kind of individual (e.g. an aggressive character or a cheerful one). Thus, this talk also will explore how to provide the agent with a personality that can be appreciated by the interlocutor.

In summary, this talk introduces how to find a characterization of the dynamic structure of facial expressions in two different levels. The high level focuses on obtaining the higher-level semantic structure underlying the facial expression space. And, the low-level contains the cues that allow us to replicate any expression by defining the particular movements that conform it, so to say, allow us to map the semantic space and the facial expressions. Last but not least, we will comment the implicit indication of the mapping between this semantic space for facial expressions and the personality space.

Talk MA-Talk: Material Parameter Extraction From Photos

12.10.2018 11:00
Seminarraum G30

Speaker(s): Sascha Fricke

The extraction of material parameters from photographs involves a process generally known as inverse rendering. This process is highly ambiguous and thus difficult to solve. Physically based shading and rendering systems allow the synthesis of believable images from such material parameters. Inverting this process directly is unfortunately not possible. Reformulating this into an optimization problem would allow the estimation of these properties by Gradient Descent. Derivatives of the rendering process with respect to the material parameters are however difficult to find due to discontinuous integrals and even if approximate derivatives are found, the ambiguity of the problem still leads to local minima that do not correspond to the desired material properties.


In the last years, convolutional neural network based systems have been shown to be capable of extracting these material parameters under certain restrictions. Unfortunately, the resulting extracted parameters are either in a parametrization, which is not useful for further use in game or film productions, or are not spatially varying and hence don’t contain enough information. Systems, that extract spatially varying parameters in the desired parametrization do exist, but are mostly only able to extract repeating, regular texture patterns from flat surfaces under simple lighting conditions.

In this thesis, a physically based, differentiable rendering system approach is presented and evaluated that is coupled with an initial, coarse estimation from a convolutional neural network. This system is able to improve the quality of estimations of both individual approaches and can be used in a general and messy real world setting to extract reflectance properties from photos that can be used as textures on triangle based geometry in real time or offline rendering systems.

Talk BA-Talk: Improving Training of Convolutional Neural Networks using Visualization Techniques

17.08.2018 13:30
Seminarraum G30

Speaker(s): Jann-Ole Henningson

Talk MA-Talk: Analyzing the Performance of Deep Neural Networks on Synthetic Training Data

17.08.2018 13:00
Seminarraum G30

Speaker(s): Meng Wang

Talk MA-Talk: An Augmented Reality Framework to Support the Implementation of Educational Applications

22.06.2018 13:00 - 22.06.2018 13:30
G30

Speaker(s): Manuel Behlen

Talk BA-Vortrag: Implementierung und Analyse von Fluid-Kontrolle mittels automatischer Differentiation

27.04.2018 10:00
Informatikzentrum, Seminarraum G30

Speaker(s): Martin Busch

Talk Humanness of virtual agents

16.04.2018 13:00
Seminarraum ICG (IZ G30)

Speaker(s): Katharina Legde

BTU Cottbus

Since computers are increasingly being used in all aspects of daily life, it would be of great advantage if we could communicate with them the same way we would interact with other people. The field of affective interfaces is working towards making computers more accessible by giving them natural-language abilities, including using synthesized speech, facial expressions, and virtual body motions. Such virtual characters often have adult bodies. An adult interface agent usually leads users to expect advanced communicational and social skills. Since computer social skills are still under-developed, users tend to be rather intolerant towards such an agent and find them less likable and appealing. This talk will discuss the challenges of creating an agent with human-like communicational and social skills to thereby raise the acceptance towards virtual avatars.

Talk Teamprojekt-Abschluss: World Builder VR Toolkit Continued

26.03.2018 13:00
ICG Lab, Campus Nord

Präsentation der Ergebnisse des studentischen Teamprojekts.

Talk BA-Talk: From Chairs to Humans: Specializing FlowNet 2 to non-rigid Human Motion

27.02.2018 14:00
Informatikzentrum, Seminarraum G30

Speaker(s): Maximilian Homann

Talk Das Weltall in Farbe und 3D

21.02.2018 19:00
Planetarium Wolfsburg

Speaker(s): Marcus Magnor

Public lecture at the planetarium Wolfsburg (website)

Ob in Science Fiction-Filmen, Computerspielen oder im Planetarium: das Weltall ist reich an Formen und Farben. Dabei hat wohl noch niemand  mit eigenen Augen einen echten astronomischen Nebel in bunt und 3D gesehen. Wie sähe es wohl vor Ort wirklich aus, wenn wir zum Ring-, Orion- oder Pferdekopfnebel fliegen könnten?

Talk Immersive Digital Reality

12.01.2018 10:15
Tampere University of Technology, Finland

Speaker(s): Marcus Magnor

Keynote presentation at VR Walkthrough Technology Day, TU Tampere, Finland (presentation video)

Since the times of the Lumière brothers, the way we watch movies hasn’t fundamentally changed: whether in movie theaters, on mobile devices, or on TV at home, we still experience movies as outside observers, watching the action through a “peephole” whose size is defined by the angular extent of the screen. As soon as we look away from the screen or turn  around, we are immediately reminded that we are only “voyeurs”. With full field-of-view, head-mounted and tracked displays available now on the consumer market, this outside-observer paradigm of visual entertainment is giving way to a fully immersive experience that encompasses the viewer and is able to draw us in much more than was possible before.

Current endeavors towards immersive visual entertainment, however, are still almost entirely based on 3D graphics-generated content, limiting application scenarios to virtual worlds only. The reason is that in order to provide for stereo vision and ego-motion parallax, which are essential for genuine visual immersion perception, the scene must be rendered in real-time from arbitrary vantage points. While this can be easily accomplished for 3D graphics via standard GPU rendering, it is not at all straight-forward to do the same from conventional video footage acquired of real-world events.

In my talk I will outline avenues of research toward enabling the immersive experience of real-world recordings, enhancing the immersive viewing experience by taking perceptual issues into account, and extending visual immersion beyond a single viewer to create a collectively experienceable immersive real-world environment.

Talk MA-Talk: Fast high-resolution GPU-based Computed Tomography

22.12.2017 13:00
Informatikzentrum, Seminarraum G30

Speaker(s): Markus Wedekind