11 research outputs found

    High Dynamic Range Mapping for Synthetic Aperture Radar Images

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    Luminance compression is often performed for high dynamic range images (still images and videos). A nonlinear tone mapping is applied for the compression in order to reproduce high dynamic range images using devices with a more limited (low) dynamic range. The images obtained after mapping may provide significant content differences in comparison to original data. This can be found for both optical and non-optical images. In this paper, we consider non-optical high dynamic range images, such as synthetic aperture radar images. Particularly, luminance compression may produce unwanted effects. Artificial objects found in an image and speckle noise may significantly affect the quality after tone mapping. In this paper, we consider several examples related to synthetic aperture radar images, as well as several global and a local luminance reduction method. The experimental analysis includes a comparison of several quality assessment methods

    Animation Content in Frame Analysis

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    Animation frame content is analyzed in this paper. The animation found in frame/video content is usually characterized by specific color distribution and texture. The existence of animation within a frame can be described by carefully selected features. We analyzed both fully and partially animated frames. Here, we present our initial results related to automatic animation interpretation using different types of video sequences

    An Adaptive Channel Model for VBLAST in Vehicular Networks

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    The wireless transmission environment in vehicular ad hoc systems varies from line of sight with few surroundings to rich Rayleigh fading. An efficient communication system must adapt itself to these diverse conditions. Multiple antenna systems are known to provide superior performance compared to single antenna systems in terms of capacity and reliability. The correlation between the antennas has a great effect on the performance of MIMO systems. In this paper we introduce a novel adaptive channel model for MIMO-VBLAST systems in vehicular ad hoc networks. Using the proposed model, the correlation between the antennas was investigated. Although the line of sight is ideal for single antenna systems, it severely degrades the performance of VBLAST systems since it increases the correlation between the antennas. A channel update algorithm using single tap Kalman filters for VBLAST in flat fading channels has also been derived and evaluated. At 12 dB Es/N0, the new algorithm showed 50% reduction in the mean square error (MSE) between the actual channel and the corresponding updated estimate compared to the MSE without update. The computational requirement of the proposed algorithm for a p×q VBLAST is 6p×q real multiplications and 4p×q real additions
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