Sketch-Based Image Retrieval and Synthesis

We introduce a system for progressively creating images through a simple sketching and compositing interface. A large database of images is searched for matches to a user's binary outline sketch; the results of this search can be combined interactively with the current image. mehr zu: Sketch-Based Image Retrieval and Synthesis

MultiTouch

In winter 2007/08 a multi touch table has been built in our group. We designed and constructed the table in a student project. The table is based on the FTIR technology. We enhanced the robustness of our table against ambient light by alternating the LEDs in sync with the camera. mehr zu: MultiTouch

Depth Imaging

Since 2007 we are working on depth imaging. We combine the depth images from either time-of-flight or stereo cameras with color images. We aim on not just gathering depth information from these systems alone or by fusing them, but also visualize the depth information directly. This includes augmented reality scenarios as well as image or video manipulation. mehr zu: Depth Imaging

FiberMesh: Designing Freeform Surfaces with 3D Curves

We have created a system for designing freeform surfaces with a collection of 3D curves. The user first creates a rough 3D model by using a sketching interface. Unlike previous sketching systems, the user-drawn strokes stay on the model surface and serve as handles for controlling the geometry. The user can add, remove, and deform these control curves easily, as if working with a 2D line drawing. The curves can have arbitrary topology; they need not be connected to each other. For a given set of curves, the system automatically constructs a smooth surface embedding by applying functional optimization. Our system provides real-time algorithms for both control curve deformation and the subsequent surface optimization. We show that one can create sophisticated models using this system, which have not yet been seen in previous sketching or functional optimization systems. mehr zu: FiberMesh: Designing Freeform Surfaces with 3D Curves

Sketch based modeling

In this work we present a method for the intuitive editing of surface meshes by means of view-dependent sketching. In most existing shape deformation work, editing is carried out by selecting and moving a handle, usually a set of vertices. Our system lets the user easily determine the handle, either by silhouette selection and cropping, or by sketching directly onto the surface. Subsequently, an edit is carried out by sketching a new, view-dependent handle position or by indirectly influencing differential properties along the sketch. Combined, these editing and handle metaphors greatly simplify otherwise complex shape modeling tasks. mehr zu: Sketch based modeling

Laplacian Surface Editing

Surface editing operations commonly require geometric details of the surface to be preserved as much as possible. We argue that geometric detail is an intrinsic property of a surface and that, consequently, surface editing is best performed by operating over an intrinsic surface representation. mehr zu: Laplacian Surface Editing

Real-time Image Dehazing - Christian Thurow

12. März 2012

In this thesis we develop a software system that allows the user to browse large image databases consisting of millions of images. Unlike existing search engines, which try to find images by their textual annotations, this system uses information provided by the image itself. Furthermore, the user is able to explore the database by navigating into different directions of image characteristics. mehr zu: Real-time Image Dehazing - Christian Thurow

Keyword-Based Image Browsing of Large Image Databases - Sebastian Bach

01. Februar 2011

This study presents several different image browsing approaches based on tags. The data this study is based upon is described and how an inverted document index based on the images as documents and the tags as index keys is generated. Clustering is performed to identify semantic groups of tags contained in the inverted document index. Finally, applications for static and dynamic image browsing of the inverted document index and the browsing of pre-computed cluster hierarchies are presented and the results evaluated. mehr zu: Keyword-Based Image Browsing of Large Image Databases - Sebastian Bach

Browsing large image databases - Ronald Richter

12. November 2010

In this thesis we develop a software system that allows the user to browse large image databases consisting of millions of images. Unlike existing search engines, which try to find images by their textual annotations, this system uses information provided by the image itself. Furthermore, the user is able to explore the database by navigating into different directions of image characteristics. mehr zu: Browsing large image databases - Ronald Richter

Shape Modeling with Sketched Feature Lines in Immersive 3D Environments - Helen Perkunder

12. November 2010

The aim of this thesis is to develop an interactive technique allowing to create 3D-objects in an immersive 3D environment. Immersive 3D environments are used for product-development and -review. Research on sketching shows that the prevalent technique in the early phase of product-design is still simple sketching on paper. The thesis is supervised by Fraunhofer-Institute for Production Systems and Design Technology IPK, Berlin. mehr zu: Shape Modeling with Sketched Feature Lines in Immersive 3D Environments - Helen Perkunder

Markerless Identification of Interactive Devices on Multi Touch Surfaces - Stefan Dippl

12. November 2010

This thesis focuses on recognition of and interaction with markerless objects which may function as tools for overview+detail or focus+context applications as described by Andy Cockburn et al. [Cockburn et al.2008]. Markers usually ease the recognition of objects but require special preparation of each object. For applications exposed to public access this is an unwelcome limitation. The general idea behind is comparable to existing multitouch projects in this group but in contrast multiple self-sustaining devices are used that are in no other way but a wireless network connection attached to the computer running the actual application. For a failsafe and unique identification of those markerless devices it is necessary for the touch table to actually "see" the devices placed on its surface. For this purpose a technique called "diffiuse illumination" (DI) is used. mehr zu: Markerless Identification of Interactive Devices on Multi Touch Surfaces - Stefan Dippl

Automatic page frame registration of digitized text images using connected components - Marco Klindt

11. Februar 2010

While more and more documents are being stored, transmitted and used only in a digital format, old books or other printed materials have to be digitized either for archival reasons or to be usable in further processing applications. During the image acquisition process either by flatbed scanners or by digital cameras artefacts like noise, borders, skew, perspective distortion, or warping might be introduced, all of which may diminish further usability of the digital copies. mehr zu: Automatic page frame registration of digitized text images using connected components - Marco Klindt

Augmentation of Real-Time Registered Surfaces using a Projector-3D Camera System - Raul Mircea Gigea

29. Januar 2010

Diese Arbeit stellt ein spezialisiertes Spatial Augmented Reality System vor, das beliebig dynamische Umgebungen in Echtzeit und ohne Vorwissen augmentieren kann. Die geometrische Information über die Umgebung wird auch für die Augmentierung benutzt. Dies wird erreicht, indem ein SAR System um das Benutzen von in Echtzeit erfassten Tiefendaten erweitert wird. Die Tiefendaten werden von einer Time-Of-Flight Photonic Mixing Device (PMD) in Echtzeit geliefert. Diese Information ist notwendig, um die räumliche Beziehung mit der Anzeigeoberfläche zu erhalten. mehr zu: Augmentation of Real-Time Registered Surfaces using a Projector-3D Camera System - Raul Mircea Gigea

Dynamic Molecular Surfaces - Norbert Lindow

28. Januar 2010

This thesis presents existing algorithms, like the contour-buildup algorithm or the powercell algorithm, and modifies and parallelizes them for a very fast computation of the SES or MSS. Powerful tools for parallelization are OpenMP and CUDA. Another focus of this thesis is the realtime visualization of molecular surfaces. It will be investigated whether realtime visulization is possible by triangulation or GPU based raycasting. In addition to molecular surfaces also molecular properties shall be displayed by color-coding. mehr zu: Dynamic Molecular Surfaces - Norbert Lindow

Evaluating time-of-flight sensors using an industrial robot - Martin Müllenhaupt

29. Januar 2010

Durch Fortschritte in der Halbleiterfertigung erleben ToF Tiefenbildsensoren in den letzten Jahren erheblichen Aufwind. Eine neue und bedeutende Art von ToF Sensoren basiert auf der Technik eines Photomischdetektors (PMD). Bei dieser Technik wird moduliertes Infrarotlicht zur Berechnung der Lichtlaufzeit verwendet. Dieses Verfahren verspricht, kostengünstige und kompakte Sensoren hoher Geschwindigkeiten zu ermöglichen. Untersuchungen der letzten Jahre zeigten jedoch, dass mehrere systematische Fehler die gemessenen Tiefendaten verfälschen. Eine umfassende Untersuchung dieser Fehler ist daher sehr aufwändig, soll der gesamte Arbeitsbereich des Sensors untersucht und kalibriert werden. Ziel dieser Arbeit ist es, eine Methode zu entwickeln, wie mithilfe eines Industrieroboter umfassende Messungen dieser Art durchgeführt werden können. Die aufgenommenen Daten wurden analysiert und mit den Ergebnissen ähnlicher Arbeiten verglichen. Daraus wurde ein Modul entwickelt, das eine effiziente Echtzeitkorrektur der Tiefendaten ermöglicht und den durchschnittlichen Fehler von 162,3mm auf 17,3mm senkt. mehr zu: Evaluating time-of-flight sensors using an industrial robot - Martin Müllenhaupt

Object recognition in a multitouch environment by combining Diffuse Illumination and Frustrated Total Internal Reflection - Björn Breitmeyer

26. November 2009

Multitouch has become popular in the last years, as the production of such systems has become a lot cheaper through optical techniques. All of these techniques rely on invisible light (mostly infrared) reflections imaged by a camera. One of the more popular techniques is based on the Frustrated Total Internal Reflection (FTIR) effect, it relies on the change of the refraction angle issued through pressure on the display. Another technique is based on Diffuse Illumination (DI) and relies on direct reflections. DI allows us to track and recognize passive markers made of reflective materials. Those can be mounted on any object of the appropriate size. To distinguish markers from each other they can contain unique patterns to uniquely identify the marker and hence the object, such markers are called fiducials. Since our tracking software takes reference frames to remove ambient light, we can easily detect active markers as the they are the only source of light. Through different geometric forms of active markers an object can be identified. Such a geometric form can also originate through pressure of an object in an FTIR setup. The main goal is to combine these methods to create an object recognition that is solid and fast enough to provide a smooth detection. mehr zu: Object recognition in a multitouch environment by combining Diffuse Illumination and Frustrated Total Internal Reflection - Björn Breitmeyer

Combining Diffuse Illumination and Frustrated Total Internal Reflection for touch detection - Andreas Holzammer

26. November 2009

The main idea of the thesis is to combine FTIR and DI to enhance the interaction between multi touch surfaces and the user. FTIR can be used to determine whether a finger is touching the surface, but this technique can not be used to determine if specific touches belong together (fingers of a hand). DI can be used to find a silhouette of the hand and therefore touches can be recognized as a hand. mehr zu: Combining Diffuse Illumination and Frustrated Total Internal Reflection for touch detection - Andreas Holzammer

Gradient Domain Video Editing - Carsten Zander

26. November 2009

This thesis presents a software system for video editing. Instead of manipulating the objects in a video, for instance by alpha matting, it uses the gradients of the video and offers tools for editing them by different operators. Then the gradients are reconstructed by solving a Poisson equation. All this is done in 3D, for the whole video all at once, using time as the third dimension. mehr zu: Gradient Domain Video Editing - Carsten Zander

Combining Pen and Multi-Touch Displays for Focus+Context Interaction - Stefan Elstner

16. Januar 2009

Die vorliegende Arbeit stellt ein neuartiges Focus+Context-System vor. Ein Multi-Touch-Tisch, der auf Frustrierter Totalreflexion (FTIR) basiert und eine große Bildfläche bietet, wird als Context verwendet. Ein Pen-Display, der Focus, wird auf die Bildfläche gelegt und stellt genau den Ausschnitt in einer hohen Auflösung dar, den es auf der Bildfläche einnimmt. Diverse Änderungen der Software ermöglichen die Erkennung des Pen-Displays auf dem Tisch. Ausserdem wird aufgezeigt, wie die Erkennung von Objekten, die sich auf dem Tisch befinden, generell mit FTIR möglich ist. mehr zu: Combining Pen and Multi-Touch Displays for Focus+Context Interaction - Stefan Elstner

User Interfaces based on a hand-held projection screen - Kristian Bermann

09. Januar 2009

In dieser Diplomarbeit werden Hardware- und ein Softwaresystem vorgestellt, mit denen es dem Nutzer möglich ist Objekte im virtuellen dreidimensionalen Raum auf eine intuitive Art und Weise zu erkunden. Die vorgestellte Hardware besteht aus einer Leinwand, die der Benutzer in einer Hand halten kann und einem Stift für die andere Hand. Die virtuelle Kamera, durch die das 3D-Objekt betrachtet wird, kann durch Veränderung der Leinwandpose (Position und Orientierung) gesteuert werden. Der zur Leinwand gehörige Stift ersetzt die Maus und kann wie ein normaler Stift benutzt werden um direkt auf der Leinwand den Cursor zu bewegen und darauf zu zeichnen. mehr zu: User Interfaces based on a hand-held projection screen - Kristian Bermann

Korrespondenzanalyse mittels Voronoi-Polen - Oliver Langner

08. September 2008

Die Arbeit befasst sich damit, zwei 3D-Oberflächen anhand von speziellen Punkten, sogenannten Voronoi-Polen, zu matchen. Ausgehend von zwei Objekten, die vollständige oder nur teilweise überlappende Partien einer Oberflächenabtastung zeigen, werden diese in ein gemeinsames Koordinatensystem transformiert und können dann zusammengefasst werden. Die für die Transformation benötigten Korrespondenzbeziehungen zweier Objekte werden nicht im Ortsraum, sondern im translations- und rotationsinvarianten Merkmalsvektorraum aufgestellt, sodass keine initiale Ausrichtung zwischen den Objekten vorausgesetzt werden muss. Im Rahmen der Diplomarbeit wurde eine Anwendung implementiert, die den Sachverhalt prototypisch prüfen kann. mehr zu: Korrespondenzanalyse mittels Voronoi-Polen - Oliver Langner

3D Rekonstruktion aus Tiefen- und Stereo-Bildern für Augmented Reality Anwendungen - Antoine Mischler

08. Dezember 2007

Wir stellen ein neuartiges System vor, welches die Ausführung von Augmented Reality (erweiterte Realität) Anwendungen mit der Verwendung von Tiefeninformationen in Echtzeit erlaubt. Das System besteht aus einer 3D PMD Kamera, die von einem Stereopaar ergänzt wird. Die PMD Kamera erfasst die Tiefe jedes einzelnen Pixels. Die Qualität dieser Tiefenkarte wird bewertet, um die unzuverlässigen Pixel mit Hilfe von Stereo zu verbessern. mehr zu: 3D Rekonstruktion aus Tiefen- und Stereo-Bildern für Augmented Reality Anwendungen - Antoine Mischler

MeshSketch: Automated, Sketch-based Editing of Triangular Meshes - Johannes Zimmermann

08. Dezember 2007

Das von uns entwickelte System erlaubt dem Benutzer Modifikationen von Modellkonturen direkt in der entsprechenden Modellansicht zu skizzieren, leitet die zu modifizierende Kontur aus dieser Benutzereingabe ab, bestimmt den letztendlich zu deformierenden Bereich des Modells und wendet diese Parameter schließlich mit einer gegebenen Deformationsmethode an. mehr zu: MeshSketch: Automated, Sketch-based Editing of Triangular Meshes - Johannes Zimmermann

Integration of Non-Photorealistic Rendering Techniques for 3D Models in Processing - Katrin Lang

30. April 2009

This thesis presents the implemenation of a non-photorealistic renderer for the Processing API (Application Programming Interface). Non-photorealistic rendering (NPR) is inspired by the expressiveness of animated cartoons, paintings and drawings. Other techniques draw upon traditional information graphics, where clarifying shape and structure are superior goals to lifelike depiction. mehr zu: Integration of Non-Photorealistic Rendering Techniques for 3D Models in Processing - Katrin Lang