2007/4

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    The Use of Wavelets in Image Interpolation: Possibilities and Limitations
    (Společnost pro radioelektronické inženýrství, 2007-12) Dumic, Emil; Grgic, Sonja; Grgic, Mislav
    Discrete wavelet transform (DWT) can be used in various applications, such as image compression and coding. In this paper we examine how DWT can be used in image interpolation. Afterwards proposed method is compared with two other traditional interpolation methods. For the case of magnified image achieved by interpolation, original image is unknown and there is no perfect way to judge the magnification quality. Common approach is to start with an original image, generate a lower resolution version of original image by downscaling, and then use different interpolation methods to magnify low resolution image. After that original and magnified images are compared to evaluate difference between them using different picture quality measures. Our results show that comparison of image interpolation methods depends on downscaling technique, image contents and quality metric. For fair comparison all these parameters need to be considered.
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    On the Relationship between Integer Lifting and Rounding Transform
    (Společnost pro radioelektronické inženýrství, 2007-12) Prochaska, Jan; Vargic, Radoslav
    In this paper we analyze the relationship between integer Lifting scheme and Rounding transform as means to compute the wavelet transform in signal processing area. We bring some new results which better describe relationship, reversibility and equivalence of integer lifting scheme and rounding transform concept.
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    Testing of DVB-H Mobile Terminals Capability
    (Společnost pro radioelektronické inženýrství, 2007-12) Prokopec, Jan; Kratochvil, Tomas
    This paper deals with the transmission of digital television to the DVB-H mobile terminals and interaction of DVB-H system with GSM/UMTS network. The mobile terminals testing approach is introduced including the testing transmission system in the laboratory of digital television and mobile communications at the Department of Radio Electronics, Brno University of Technology. This system can be used for efficient analysis in research and development of near future commercial DVB-H networks. The task of the DVB-H providers is to offer commercial mobile terminals capable to operate in DVB-H network with GSM/UMTS interactivity channel.
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    ICA Model Order Estimation Using Clustering Method
    (Společnost pro radioelektronické inženýrství, 2007-12) Ruckay, Lukas; Stastny, Jakub; Sovka, Pavel
    In this paper a novel approach for independent component analysis (ICA) model order estimation of movement electroencephalogram (EEG) signals is described. The application is targeted to the brain-computer interface (BCI) EEG preprocessing. The previous work has shown that it is possible to decompose EEG into movement-related and non-movement-related independent components (ICs). The selection of only movement related ICs might lead to BCI EEG classification score increasing. The real number of the independent sources in the brain is an important parameter of the preprocessing step. Previously, we used principal component analysis (PCA) for estimation of the number of the independent sources. However, PCA estimates only the number of uncorrelated and not independent components ignoring the higher-order signal statistics. In this work, we use another approach - selection of highly correlated ICs from several ICA runs. The ICA model order estimation is done at significance level α = 0.05 and the model order is less or more dependent on ICA algorithm and its parameters.
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    Single Frequency Networks (SFN) in Digital Terrestrial Broadcasting
    (Společnost pro radioelektronické inženýrství, 2007-12) Ricny, Vaclav
    The paper deals with principles and properties of single frequency networks of digital television and radio transmitters. Basic definitions and contextual relationships (guard interval, area of SFN, influence of used modulation parameters etc.) are explained.