TY - RPRT A1 - Exner, David A1 - Bruns, Erich A1 - Kurz, Daniel A1 - Grundhöfer, Anselm A1 - Bimber, Oliver T1 - Fast and Reliable CAMShift Tracking N2 - CAMShift is a well-established and fundamental algorithm for kernel-based visual object tracking. While it performs well with objects that have a simple and constant appearance, it is not robust in more complex cases. As it solely relies on back projected probabilities it can fail in cases when the object's appearance changes (e.g. due to object or camera movement, or due to lighting changes), when similarly colored objects have to be re-detected or when they cross their trajectories. We propose extensions to CAMShift that address and resolve all of these problems. They allow the accumulation of multiple histograms to model more complex object appearance and the continuous monitoring of object identi- ties to handle ambiguous cases of partial or full occlusion. Most steps of our method are carried out on the GPU for achieving real-time tracking of multiple targets simultaneously. We explain an ecient GPU implementations of histogram generation, probability back projection, im- age moments computations, and histogram intersection. All of these techniques make full use of a GPU's high parallelization. KW - Bildverarbeitung KW - CAMShift KW - Kernel-Based Tracking KW - GPU Programming KW - CAMShift KW - Kernel-Based Tracking KW - GPU Programming Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20091217-14962 ER - TY - RPRT A1 - Stratmann, Bernhard T1 - Healthy Cities Australia : A Long-Term Study of a Success Story N2 - The Healthy Cities concept is based on the New Public Health approach. It aims at health promotion at the local level by encouraging community participation and intersectoral collaboration. The paper summarizes findings of research on the Australian Healthy Cities Projects. The long-term study was conducted by the author and is based on a method mix. The results of the study can partially be transferred to Healthy Cities initiatives in other parts of the world. The concept can be linked to Local Agenda 21 initiatives (sustainable urban development). N2 - Weltweit beteiligen sich mehrere tausend Kommunen an dem Healthy Cities Projekt der Weltgesundheitsorganisation (WHO), auch in Deutschland gehören viele Städte dem internationalen Netzwerk an. In der vom Autor durchgeführten Langzeitstudie werden die Erfolgsbedingungen lokaler Gesunde-Städte-Projekte untersucht. Die Studie stützt sich dabei auf die Untersuchung australischer Projekte. Die Ergebnisse lassen sich z.T. auf Healthy-Cities-Projekte in anderen Regionen der Welt übertragen. Auch lassen sich deutliche Parallelen zu Ansätzen nachhaltiger Stadtentwicklung (z.B. Lokale Agenda 21) feststellen, so dass Synergien entstehen können. KW - Stadtentwicklung KW - Gesundheitswissenschaften und öffentliche Gesundheitsförderung KW - Australien KW - Gesunde-Städte-Projekt KW - Healthy Cities Project Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20090729-14824 ER - TY - RPRT A1 - Bimber, Oliver T1 - Superimposing Dynamic Range N2 - Replacing a uniform illumination by a high-frequent illumination enhances the contrast of observed and captured images. We modulate spatially and temporally multiplexed (projected) light with reflective or transmissive matter to achieve high dynamic range visualizations of radiological images on printed paper or ePaper, and to boost the optical contrast of images viewed or imaged with light microscopes. KW - Bildverarbeitung KW - CGI KW - Computergraphik KW - Kontrast KW - Projektor-Kamera Systeme KW - Hoher Dynamikumfang KW - Mikroskopie KW - Contrast KW - Projector-Camera Systems KW - High Dynamic Range KW - Microscopy Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20090303-14662 ER - TY - RPRT A1 - Gross, Tom A1 - Beckmann, Christoph T1 - CoLocScribe: A Media Space for Information Disclosure in Storytelling N2 - Digital storytelling of remote social interaction, where the situation of a remote group distributed over two locations is captured and a story is generated for later retrieval, can provide valuable insight into the structure and processes in a group. Yet, capturing these situations is a challenge—both from a technical perspective, and from a social perspective. In this paper we present CoLocScribe: a concept and prototype of an advanced media space featuring ubiquitous computing technology for capturing remote social interaction as well as a study of its use providing valuable feedback for the captured persons as well as input for the authors. KW - Angewandte Informatik KW - Ubiquitous Computing KW - Computer-Supported Cooperative Work KW - Media Space KW - Ubiquitous Computing KW - Computer-Supported Cooperative Work KW - Media Space Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20081103-14361 ER - TY - RPRT A1 - Gross, Tom A1 - Schirmer, Maximilian T1 - CollaborationBus Aqua: An Editor for Storytelling in Mixed Reality Settings N2 - Capturing the interaction of users in a room based on real-world and electronic sensors provides valuable input for their interactive stories. However, in such complex scenarios there is a gap between the huge amount of rather fine-grained data that is captured and the story summarising and representing the most significant aspects of the interaction. In this paper we present the CollaborationBus Aqua editor that provides an easy to use graphical editor for capturing, authoring, and sharing stories based on mixed-reality scenarios. KW - Angewandte Informatik KW - Ubiquitous Computing KW - Computer-Supported Cooperative Work KW - Editor KW - Konfiguration KW - Ubiquitous Computing KW - Computer-Supported Cooperative Work KW - Editor KW - configuration Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20081103-14359 ER - TY - RPRT A1 - Bimber, Oliver A1 - Iwai, Daisuke T1 - Superimposing Dynamic Range N2 - We present a simple and cost-efficient way of extending contrast, perceived tonal resolution, and the color space of static hardcopy images, beyond the capabilities of hardcopy devices or low-dynamic range displays alone. A calibrated projector-camera system is applied for automatic registration, scanning and superimposition of hardcopies. We explain how high-dynamic range content can be split for linear devices with different capabilities, how luminance quantization can be optimized with respect to the non-linear response of the human visual system as well as for the discrete nature of the applied modulation devices; and how inverse tone-mapping can be adapted in case only untreated hardcopies and softcopies (such as regular photographs) are available. We believe that our approach has the potential to complement hardcopy-based technologies, such as X-ray prints for filmless imaging, in domains that operate with high quality static image content, like radiology and other medical fields, or astronomy. KW - Bildverarbeitung KW - CGI KW - Computergraphik KW - Kontrast KW - Projektor-Kamera Systeme KW - Hoher Dynamikumfang KW - Contrast KW - Projector-Camera Systems KW - High Dynamic Range Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20080422-13585 ER - TY - RPRT A1 - Gross, Tom A1 - Oemig, Christoph T1 - Presence, Privacy, and PRIMIFaces: Towards Selective Information Disclosure in Instant Messaging N2 - Efficient distant cooperation often requires spontaneous ad-hoc social interaction, which is only possible with adequate information on the prospective communication partner. This often requires disclosing and sharing personal information via tools such as instant messaging systems and can conflict with the users’ wishes for privacy. In this paper we present an initial study investigating this trade-off and discuss implications for the design of instant messaging systems. We present the functionality and design of the PRIMIFaces instant messaging prototype supporting flexible identity management and selective information disclosure. KW - Angewandte Informatik KW - Awareness KW - Gruppengewahrsein KW - Privatsphäre KW - Reziprozität KW - Ubiquitous Computing KW - Awareness KW - Group Awareness KW - Privacy KW - Reciprocity KW - Ubiquitous Computing Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20080314-13452 ER - TY - RPRT A1 - Grosse, Max A1 - Bimber, Oliver T1 - Coded Aperture Projection N2 - In computer vision, optical defocus is often described as convolution with a filter kernel that corresponds to an image of the aperture being used by the imaging device. The degree of defocus correlates to the scale of the kernel. Convolving an image with the inverse aperture kernel will digitally sharpen the image and consequently compensate optical defocus. This is referred to as deconvolution or inverse filtering. In frequency domain, the reciprocal of the filter kernel is its inverse, and deconvolution reduces to a division. Low magnitudes in the Fourier transform of the aperture image, however, lead to intensity values in spatial domain that exceed the displayable range. Therefore, the corresponding frequencies are not considered, which then results in visible ringing artifacts in the final projection. This is the main limitation of previous approaches, since in frequency domain the Gaussian PSF of spherical apertures does contain a large fraction of low Fourier magnitudes. Applying only small kernel scales will reduce the number of low Fourier magnitudes (and consequently the ringing artifacts) -- but will also lead only to minor focus improvements. To overcome this problem, we apply a coded aperture whose Fourier transform has less low magnitudes initially. Consequently, more frequencies are retained and more image details are reconstructed. KW - Association for Computing Machinery / Special Interest Group on Graphics KW - CGI KW - Projektion KW - Blende Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20080227-13020 ER - TY - RPRT A1 - Grundhöfer, Anselm A1 - Bimber, Oliver T1 - Dynamic Bluescreens N2 - Blue screens and chroma keying technology are essential for digital video composition. Professional studios apply tracking technology to record the camera path for perspective augmentations of the original video footage. Although this technology is well established, it does not offer a great deal of flexibility. For shootings at non-studio sets, physical blue screens might have to be installed, or parts have to be recorded in a studio separately. We present a simple and flexible way of projecting corrected keying colors onto arbitrary diffuse surfaces using synchronized projectors and radiometric compensation. Thereby, the reflectance of the underlying real surface is neutralized. A temporal multiplexing between projection and flash illumination allows capturing the fully lit scene, while still being able to key the foreground objects. In addition, we embed spatial codes into the projected key image to enable the tracking of the camera. Furthermore, the reconstruction of the scene geometry is implicitly supported. KW - Association for Computing Machinery / Special Interest Group on Graphics KW - CGI KW - Maschinelles Sehen KW - Farbstanzen KW - Erweiterte Realität KW - Projektion KW - Chroma Keying KW - Bildmischung KW - Augmented Reality KW - Projection KW - Chromakeying KW - Compositing Y1 - 2008 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20080226-13016 ER - TY - RPRT A1 - Gross, Tom A1 - Fetter, Mirko A1 - Liebsch, Sascha T1 - The cueTable Cooperative Multi-Touch Interactive Tabletop: Implementation and User Feedback T1 - The cueTable Cooperative Multi-Touch Interactive Tabletop: Implementation and User Feedback N2 - Es wurde ein multi-touch interaktives Tabletop als Basistechnologie zur Exploration neuer Interaktionskonzepte für kooperative multi-touch Anwendungen entwickelt. In dieser Publikation stellen wir vor, wie ein kooperatives multi-touch interaktives Tabletop basierend auf günstiger Standard-Hardware mit geringem Realisierungsaufwand gebaut werden kann. Wir präsentieren eine Software-Anwendung, die wir dafür entwickelt haben. And wir berichten über Benutzerkommentare zum Tabletop und der Anwendung. N2 - We developed a multi-touch interactive tabletop as a base technology to explore new interaction concepts for cooperative multi-touch applications. In this paper we explain how to build a cooperative multi-touch interactive tabletop with standard and low-budget hardware and little implementation effort. We present a software application we developed. And we report on user feedback to the tabletop and the applications KW - Angewandte Informatik KW - Interaktiver Tabletop KW - kooperatives Multi-Touch KW - Implementation KW - Benutzerkommentare KW - Interactive Tabletop KW - Cooperative Multi-Touch KW - Implementation KW - User Feedback Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:wim2-20111215-6331 ER -