12. March 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.
more to: Real-time Image Dehazing - Christian Thurow
01. February 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.
more to: Keyword-Based Image Browsing of Large Image Databases - Sebastian Bach
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.
more to: Browsing large image databases - Ronald Richter
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.
more to: Shape Modeling with Sketched Feature Lines in Immersive 3D Environments - Helen Perkunder
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 "diffi use illumination" (DI) is used.
more to: Markerless Identification of Interactive Devices on Multi Touch Surfaces - Stefan Dippl
11. February 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.
more to: Automatic page frame registration of digitized text images using connected components - Marco Klindt
29. January 2010
This thesis presents a specialized Spatial Augmented Reality system which is able to augment arbitrary, dynamic scenes in real-time without prior knowledge of the environment, and able to use the information about the environment for geometry-aware augmentation. We do this by extending a SAR system to use flexible real-time acquired depth information from a time-of-flight photonic mixing device (PMD). This information is needed to react to environment changes and maintain the spatial relationship with the displayed image.
more to: Augmentation of Real-Time Registered Surfaces using a Projector-3D Camera System - Raul Mircea Gigea
28. January 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.
more to: Dynamic Molecular Surfaces - Norbert Lindow
29. January 2010
Time-of-flight (ToF) sensors experience a recent burst of advancement, due to the progress made in semiconductor production. A relatively new type of ToF sensors is based on the Photonic Mixer Device (PMD).
Using a modulated, incoherent light source, this sensor type promises low-cost and real-time distance acquisition. But error studies have shown that a variety of systematic errors distort the measurements of PMD sensors.
This work attempts to tackle the task of developing a method of efficiently recording calibration data for a PMD sensor by using an industrial robot.
An industrial robot with its fast movements, high accuracy and good working range is a suitable device for measurements of this type. With the help of a robot, comprehensive calibration data was recorded. The data was analyzed and compared to results of related work. A module for real-time correction of the camera data was developed. It reduces the average depth error from 162.3mm to 17.3mm.
more to: Evaluating time-of-flight sensors using an industrial robot - Martin Müllenhaupt
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.
more to: Object recognition in a multitouch environment by combining Diffuse Illumination and Frustrated Total Internal Reflection - Björn Breitmeyer
24. February 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 off ers tools for editing them by di fferent 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 the time as third dimension. The several operators which are applied to the gradient domain are developed in order to avoid artifacts, like temporal change of illumination, which are difficult to handle in the common ways of video editing. Therefore the temporal coherence of the video will be used as well. This work explains the theory of solving the Poisson equation in an efficient way as well as the documentation of the development of the operators and their eff ectiveness of reducing artifacts.
more to: Gradient Domain Video Editing - Carsten Zander
08. September 2008
The thesis deals with matchings of two 3D-surfaces by the use of special points, the so-called Voronoi poles. Given two objects, which represent the whole real object or just partial overlapping parts, these shall be transformed into a common coordinate system and may be merged then. The correspondences between both objects, that are needed for the transformation, are not set up in spatial space, but in a translation and rotation invariant feature space, to prevent from assuming any initial arrangement. Within the scope of the dissertation an application was implemented, that can check the facts prototypically.
more to: Correspondence Analysis using Voronoi Poles - Oliver Langner
