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    DigitalI: Institut für Existenzgründung

    Zeitschriftenartikel

    Thomas Bartscher

    Auf dem Sprung – Management-Ausbildung im Mittelstand

    MBA Magazin, no. 2

    2007

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    J. Bialkowski, Marcus Barkowsky, A. Kaup

    A new algorithm for reducing the requantization loss in video transcoding

    2006 14th European Signal Processing Conference

    2006

    Abstract anzeigen

    Video transcoders are devices that convert one video bitstream into another type of bitstream, either with or without standard format conversion. One step to be applied in video transcoders is the requantization of the transform coefficients, if an adaptation to a lower data rate is necessary. During this step, the quality is in most cases degraded compared to a single quantization. This is a consequence of nonoverlapping quantization characteristics of the input and the output quantizer. In this work we propose a new choice of the reconstruction level for the requantization step depending on the effective quantization curve of both quantization parameters involved. The reconstruction level is calculated such that it is centered in each effective quantization interval after requantization. Compared to the standard midpoint requantization this leads to quality gains of 3 dB PSNR for most pairs of input and output quantization parameters (QP). The algorithm is useful for intra- and inter-frame coding.

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    J. Bialkowski, Marcus Barkowsky, A. Kaup

    Overview of Low-Complexity Video Transcoding from H.263 to H.264

    2006 IEEE International Conference on Multimedia and Expo

    2006

    Abstract anzeigen

    With the standardization of H.264/AVC by ITU-T and ISO/IEC and the adaptatation into new hardware, the necessity of transcoding between existing standards and H.264 will arise to achieve interoperability between hardware devices. Because of the many new prediction parameters as well as the pixel-based deblocking filter and the new transform of H.264 this is a difficult task to perform. In our work we propose a fast cascaded pixel-domain transcoder from H.263 to H.264 for both intra- and inter-frame coding. The rate-distortion (RD) performance of the encoded bitstreams is compared to an exhaustive full-search approach. Our approach leads to 9% higher data rate in average, but the computational complexity for the prediction can be reduced by 90% and more. It will be shown that the algorithms proposed for H.263 are applicable for transcoding MPEG-2 to H.264, too

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    J. Bialkowski, Marcus Barkowsky, F. Leschka, A. Kaup

    Low-Complexity Transcoding of Inter Coded Video Frames from H.264 to H.263

    2006 IEEE International Conference on Image Processing

    2006

    Abstract anzeigen

    The presented work addresses the reduction of computational complexity for transcoding of interframes from H.264 to H.263 baseline profiles maintaining the quality of a full search approach. This scenario aims to achieve fast backward compatible interoperability inbetween new and existing video coding platforms, e.g. between DVB-H and UMTS. By exploiting side information of the H.264 input bitstream the encoding complexity of the motion estimation is strongly reduced. Due to the possibility to divide a macroblock (MB) into partitions with different motion vectors (MV), one single MV has to be selected for H.263. It will be shown, that this vector is suboptimal for all sequences, even if all existing MVs of a MB of H.264 are compared as candidate. Also motion vector refinement with a fixed ½-pel refinement window as used by transcoders throughout the literature is not sufficient for scenes with fast movement. We propose an algorithm for selecting a suitable vector candidate from the input bitstream and this MV is then refined using an adaptive window. Using this technique, the complexity is still low at nearly optimum rate-distortion results compared to an exhaustive full-search approach.

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    Marcus Barkowsky, B. Eskofier, J. Bialkowski, A. Kaup

    Influence of the Presentation Time on Subjective Votings of Coded Still Images

    Proceedings of the International Conference on Image Processing

    2006

    Abstract anzeigen

    The quality of coded images is often assessed by a subjective test. Usually the viewers get as much time as they need to find a stable result. In video sequences however, the viewer has to judge the quality in a shorter time that is defined by the changing content or a following scene cut. Therefore it is desirable to know the influence of a shorter presentation time on the perceptibility of distortions. In this paper we present the results of a suitable subjective test on coded still images. The images were presented for six different durations, ranging from 200 ms to 3 s. Special care was taken to avoid the memorization effect usually present after short presentations. The results show that the viewers tend to avoid extreme votings at short durations. The variance of the votings is also discussed in detail. Based on the result of the voting for the longest presentation time, we propose a prediction model for the voting of the shorter durations using a logistic curve fit. This presentation time model (PTM) is presented and analysed in detail.

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    U. Fecker, Marcus Barkowsky, A. Kaup

    Improving the Prediction Efficiency for Multi-View Video Coding Using Histogram Matching

    Proceedings of the Picture Coding Symposium 2006, [Isernhagen]

    2006

    ISBN: 9783000187261

    Abstract anzeigen

    Applications for video data recorded witha setup of several cameras are currently attracting increasinginterest. For such multi-view sequences, efficientcoding is crucial to handle the enormous amountof data. However, significant luminance and chrominancevariations between the different views, which oftenoriginate from imperfect camera calibration, areable to reduce the coding efficiency and the renderingquality. In this paper, we suggest the usage of histogrammatching to compensate these differences in apre-filtering step. After a description of the proposedalgorithm, it is explained how histogram matching canbe applied to multi-view video data. The effect of histogrammatching on the coding performance is evaluatedby statistically analysing prediction from temporalas well as from spatial references. For several testsequences, results are shown which indicate that theamount of spatial prediction across different cameraviews can be increased by applying histogram matching.

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    Marcus Barkowsky, R. Bitto, J. Bialkowski, A. Kaup, B. Li

    Comparison of matching strategies for temporal frame registration in the perceptual evaluation of video quality

    Proceedings of the 2nd International Workshop on Video Processing and Quality Metrics for Consumer Electronics

    2006

    ISBN: 09774739

    Abstract anzeigen

    In this paper we compare the performance of different full-frameand block-based algorithms for the temporal alignment of twovideo sequences. The setup is typical for full reference videoquality estimation in a low-bitrate scenario. Lossless and lossydigital transmission scenarios are combined with different distortionsusually found in playback devices. The results show thatthe choice of the algorithm for temporal registration depends verymuch on the type of additional distortion expected.

    DigitalF: Angewandte WirtschaftswissenschaftenS: TC Grafenau

    Beitrag (Sammelband oder Tagungsband)

    S. Wildner, Michael Scholz

    Managing Knowledge Methodically

    Multikonferenz Wirtschaftsinformatik 2006

    2006

    ISBN: 978-3936771626

    DigitalI: Institut für Existenzgründung

    Beitrag (Sammelband oder Tagungsband)

    Thomas Bartscher, W. Büning, A. Rohm

    Entzauberung von Latenzen

    Change-Tools

    2006

    DigitalI: Institut für Existenzgründung

    Zeitschriftenartikel

    Thomas Bartscher

    Personalentwicklung im Wandel

    Computerwoche, no. 18

    2006

    DigitalI: Institut für Existenzgründung

    Zeitschriftenartikel

    Thomas Bartscher

    Talente für Robotik und Automation gesucht. Bericht von der Fachmesse Automatica

    VDI Nachrichten, no. 19

    2006

    DigitalI: Institut für Existenzgründung

    Zeitschriftenartikel

    Thomas Bartscher, R. Mielke

    Wie der Markt, so die Personalarbeit

    personalmagazin, no. 11, pp. 64-67

    2006

    DigitalI: Institut für Existenzgründung

    Zeitschriftenartikel

    Thomas Bartscher

    Neugierde ist ein Erfolgsfaktor für technischen Nachwuchs

    Bericht von der Fachmesse Automatica

    VDI Nachrichten, no. 21

    2006

    DigitalI: Institut für Existenzgründung

    Buch (Monographie)

    Thomas Bartscher, R. Kasemir, R. Mielke

    Chancen für den Mittelstand – Studie Personalmanagement 2006

    2006

    DigitalF: Elektrotechnik und MedientechnikI: Institut für Existenzgründung

    Beitrag (Sammelband oder Tagungsband)

    Thomas Bartscher, A. Huber, Wolfgang Dorner

    Themennetzwerke der Wirtschaft – Eine Untersuchung des Managementcenters Deggendorf zu Chancen der wirtschaftlichen Entwicklung im Teilraum Deggendorf/Plattling

    Projekt RISE – Regional Identity and culture, Strength development & Environment action, Deggendorf

    2006

    DigitalI: Institut für Existenzgründung

    Buch (Monographie)

    Thomas Bartscher, M. Dipper

    Leadership: Reader I – IV

    AKAD Lehrbrief

    2006

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    J. Bialkowski, Marcus Barkowsky, A. Kaup

    On Requantization in Intra-Frame Video Transcoding with Different Transform Block Sizes

    2005 IEEE 7th Workshop on Multimedia Signal Processing

    2005

    DOI: 10.1109/MMSP.2005.248669

    Abstract anzeigen

    Transcoding is a technique to convert one video bit-stream into another. While homogeneous transcoding is done at the same coding standard, inhomogeneous transcoding converts from one standard format to another standard. Inhomogeneous transcoding between MPEG-2, MPEG-4 or H.263 was performed using the same transform. With the standardisation of H.264 also a new transform basis and different block size was defined. For requantization from block size 8times8 to 4times4 this leads to the effect that the quantization error of one coefficient in a block of size 8times8 is distributed over multiple coefficients in blocks of size 4times4. In our work, we analyze the requantization process for inhomogeneous transcoding with different transforms. The deduced equations result in an expression for the correlation of the error contributions from the coefficients of block size 8times8 at each coefficient of block size 4times4. We then compare the mathematical analysis to simulations on real sequences. The reference to the requantization process is the direct quantization of the undistorted signal. It will be shown that the loss is as high as 3 dB PSNR at equivalent step size for input and output bitstream. Also an equation for the choice of the second quantization step size in dependency of the requantization loss is deduced. The model is then extended from the DCT to the integer-based transform as defined in H.264

    DigitalF: Angewandte Informatik

    Beitrag (Sammelband oder Tagungsband)

    Marcus Barkowsky, J. Bialkowski, A. Kaup

    Subjektiver Videobetrachtungstest für niederratige Multimedia-Szenarien

    ITG Fachbericht 188: Elektronische Medien 2005

    2005

    ISBN: 978-3-8007-2898-5

    DigitalI: Institut für Existenzgründung

    Zeitschriftenartikel

    Thomas Bartscher

    Gelebte und erlebte Wertschätzung

    PERSONAL – Zeitschrift für Human Resource Management, vol. 57, no. 5, pp. 40-43

    2005

    DigitalI: Institut für Existenzgründung

    Zeitschriftenartikel

    Thomas Bartscher

    Chefs helfen bei Wut und Trauer: In Veränderungsprozessen müssen Führungskräfte Verhalten richtig einschätzen und adäquat reagieren

    personalmagazin, vol. 12, no. 7, pp. 64-66

    2005