Tobias Schreck

Semiautomatic Benchmarking of Feature Vectors for Multimedia Retrieval

Modern Digital Library applications store and process mas- sive amounts of information. Usually, ... more Modern Digital Library applications store and process mas- sive amounts of information. Usually, this data is not limited to raw textual or numeric data { typical applications also deal with multimedia data such as images, audio, video, or 3D geometric models. For providing eective retrieval functionality, appropriate meta data descriptors that allow calculation of similarity scores between data instances are

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MailSOM - Exploration of Electronic Mail Archives Using Self-Organizing Maps

Conference on Email and Anti-Spam, 2005

Systems for handling large electronic mail archives can leverage Information Visualization techni... more

Trajectory-based visual analysis of large financial time series data

by Tobias Schreck and Dieter Fellner

ACM SIGKDD Explorations Newsletter, 2007

... Based on the asset view, a semi-automatic alert system can be set up, monitoring current char... more

Regular TreeMap layouts for visual analysis of hierarchical data

Proceedings of the 22nd Spring Conference on Computer Graphics - SCCG '06, 2006

Hierarchical relationships play an utmost important role in many application domains. Appropriate... more

Monitoring Network Traffic with Radial Traffic Analyzer

2006 IEEE Symposium On Visual Analytics And Technology, 2006

... [5] WinPcap. http://www.winpcap.org. [6] Kulsoom Abdullah, Chris Lee, Gregory Conti, John A. ... more

Towards automatic feature vector optimization for multimedia applications

by Dieter Fellner and Tobias Schreck

Proceedings of the 2008 ACM symposium on Applied computing - SAC '08, 2008

We systematically evaluate a recently proposed method for unsupervised discrimination power analy... more We systematically evaluate a recently proposed method for unsupervised discrimination power analysis for feature se- lection and optimization in multimedia applications. A se- ries of experiments using real and synthetic benchmark data is conducted, the results of which indicate the suitability of the method for unsupervised feature selection and optimiza- tion. We present an approach for generating synthetic fea- ture

<title>A visual analysis of multi-attribute data using pixel matrix displays</title>

Visualization and Data Analysis 2007, 2007

Charts and tables are commonly used to visually analyze data. These graphics are simple and easy ... more Charts and tables are commonly used to visually analyze data. These graphics are simple and easy to understand, but charts show only highly aggregated data and present only a limited number of data values while tables often show too many data values. As a consequence, these graphics may either lose or obscure important information, so different techniques are required to

Preface to special issue on 3DOR 2010

by Tobias Schreck and R. Veltkamp

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2D Maps for Visual Analysis and Retrieval in Large Multi-Feature 3D Model Databases

IEEE Visualization, 2004

Multimedia objects are often described by high-dimensional feature vectors which can be used for ... more Multimedia objects are often described by high-dimensional feature vectors which can be used for retrieval and clustering tasks. We have built an interactive retrieval system for 3D model databases that implements a variety of different feature transforms. Recently, we have enhanced the functionality of our system by integrating a SOM-based visualization module. In this poster demo, we show how 2D

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Feature-based similarity search in 3D object databases

ACM Computing Surveys, 2005

issue, due to the growing amount of digital audio-visual information. In the case of images and v... more issue, due to the growing amount of digital audio-visual information. In the case of images and video, the growth of digital data has been observed since the introduction of 2D capture devices. A similar development is expected for 3D data, as acquisition and dissemination technology of 3D models is constantly improving. 3D objects are becoming an important type of multimedia

Retrieval and exploratory search in multivariate research data repositories using regressional features

by Tobias Schreck and Jürgen Bernard

Increasing amounts of data are collected in many areas of research and application. The degree to... more Increasing amounts of data are collected in many areas of research and application. The degree to which this data can be accessed, retrieved, and analyzed is decisive to obtain progress in fields such as scientific research or industrial production. We present a novel method supporting content-based retrieval and exploratory search in repositories of multivariate research data. In particular, functional dependencies

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STELA: sketch-based 3D model retrieval using a structure-based local approach

Since 3D models are becoming more popular, the need for effective methods capable of retrieving 3... more Since 3D models are becoming more popular, the need for effective methods capable of retrieving 3D models are becoming crucial. Current methods require an example 3D model as query. However, in many cases, such a query is not easy to get. An alternative is using a hand-draw sketch as query. We present a structure-based local approach (STELA) for retrieving 3D

Visual analytics of terrorist activities related to epidemics

IEEE Symposium on Visual Analytics Science and Technology, 2011

The task of the VAST 2011 Grand Challenge was to investigate potential terrorist activities and t... more The task of the VAST 2011 Grand Challenge was to investigate potential terrorist activities and their relation to the spread of an epidemic. Three different data sets were provided as part of three Mini Challenges (MCs). MC 1 was about analyzing geo-tagged microblogging (Twitter) messages to characterize the spread of an epidemic. MC 2 required analyzing threats to a computer

An experimental comparison of feature-based 3D retrieval methods

Proceedings - 2nd International Symposium on 3D Data Processing, Visualization, and Transmission. 3DPVT 2004, 2004

Robustness and PCA invariance Precision vs. recall in model classes Dimensionality vs. R-precisio... more Robustness and PCA invariance Precision vs. recall in model classes Dimensionality vs. R-precision The charts show that the most effective method is the depth buffer. The difference of the average R-precision values between the best performing methods is small. As a contrast, the effectiveness difference between the best and the worst feature vector is significant, up to a factor of 3. We observed that feature vectors that rely on consistent polygon orientation exhibit low retrieval rates in our database.

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DelosDLMS - The Integrated DELOS Digital Library Management System

by Tobias Schreck and Nicola Ferro

DelosDLMS is a prototype of a next-generation Digital Library (DL) management system. It is reali... more DelosDLMS is a prototype of a next-generation Digital Library (DL) management system. It is realized by combining various specialized DL functionalities provided by partners of the DELOS network of excellence. Currently, DelosDLMS combines text and audio-visual searching, offers new information visualization and relevance feedback tools, provides novel interfaces, allows retrieved information to be annotated and processed, integrates and processes sensor data streams, and finally, from a systems engineering point of view, is easily configured and adapted while being reliable and scalable. The prototype is based on the OSIRIS/ISIS platform, a middleware environment developed by ETH Zürich and now being extended at the University of Basel.

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