1,835 research outputs found

    Tone-mapping functions and multiple-exposure techniques for high dynamic-range images

    Get PDF
    For real-time imaging with digital video cameras and high-quality with TV display systems, good tonal rendition of video is important to ensure high visual comfort for the user. Except local contrast improvements, High Dynamic Range (HDR) scenes require adaptive gradation correction (tone-mapping function), which should enable good visualization of details at lower brightness. We discuss how to construct and control improved tone-mapping functions that enhance visibility of image details in the dark regions while not excessively compressing the image in the bright image parts. The result of this method is a 21-dB expansion of the dynamic range thanks to improved SNR by using multiple- exposure techniques. This new algorithm was successfully evaluated in HW and outperforms the existing algorithms with 11 dB. The new scheme can be successfully applied to cameras and TV systems to improve their contrast

    Adaptive tone-mapping transfer functions for high dynamic range video cameras

    Get PDF
    For real-time imaging with digital video cameras, good tonal rendition of video is important to ensure high visual comfort for the user. Except local contrast improvements, high dynamic range (HDR) scenes require adaptive gradation correction (tone-mapping curve) that should enable good visualization of details at lower brightness. We discuss how to construct and control optimal tone mapping curves, which enhance visibility of image details in the dark regions while not excessively compressing the image in the bright image parts. The result of this method is a 21 dB expansion of the dynamic range. The new algorithm was successfully evaluated in HW and is suited for any video system performing HDR video compression

    Background estimation and adaptation model with light-change removal for heavily cown-sampled video surveillance signals

    Get PDF
    This paper describes a background-subtraction system with light change-detection which works on a luminance QCIF-size video signal for surveillance applications. The new proposed pixel background model is controlled by a statistical threshold and is robust for cluttered background and small object motions. Moreover, (or light-change detection, we introduce temporal prediction of pixel values to estimate trends while quickly adapting to scene changes to facilitate a very sensitive detection of moving targets. Experiments show that a local contrast enhancement applied prior to down-sampling improves detection sensitivity, arid combined with the shifted sealed difference and me Wronskian determinant operators provides the best background/foreground detectio

    Evolution of a Software Maintenance Organization from Cost Center to Service Center

    Get PDF
    The paper describes experiences with the evolution of a software maintenance organization for digital set-top boxes of a leading electronics company from a cost center towards a service center. Several years ago a dedicated software maintenance group was constituted. As the costs for software maintenance were not recovered from the customers, the software maintenance group was merely considered a cost center. Through starting a metrics program for software maintenance and defining a service strategy with various service levels, the software maintenance group generated sufficient revenues to become self-supporting. An important conclusion is that the use of ITIL (IT infrastructure library) service support has helped to develop a better customer focused approach, which is considered as the most important critical success factor for a professional, self-supporting maintenance organization

    Employing a RGB-D Sensor for Real-Time Tracking of Humans across Multiple Re-Entries in a Smart Environment

    Get PDF
    The term smart environment refers to physical spaces equipped with sensors feeding into adaptive algorithms that enable the environment to become sensitive and responsive to the presence and needs of its occupants. People with special needs, such as the elderly or disabled people, stand to benefit most from such environments as they offer sophisticated assistive functionalities supporting independent living and improved safety. In a smart environment, the key issue is to sense the location and identity of its users. In this paper, we intend to tackle the problems of detecting and tracking humans in a realistic home environment by exploiting the complementary nature of (synchronized) color and depth images produced by a low-cost consumer-level RGB-D camera. Our system selectively feeds the complementary data emanating from the two vision sensors to different algorithmic modules which together implement three sequential components: (1) object labeling based on depth data clustering, (2) human re-entry identification based on comparing visual signatures extracted from the color (RGB) information, and (3) human tracking based on the fusion of both depth and RGB data. Experimental results show that this division of labor improves the system’s efficiency and classification performance

    Drive-Line Extraction from Aerial Images

    Get PDF

    An apparatus and method for detecting a tool

    Get PDF
    The apparatus is adapted to detect a tool based on a 3D image obtained by a 3D ultrasound imaging system. The apparatus comprises an image processing unit, which includes a tool detection module configured to perform a tool detection procedure. The tool detection procedure involves identifying a shadow of the tool in the 3D image and calculating the position of a "tool plane section" of the 3D image in which the entire length of the tool is represented

    Drive-Line Extraction from Aerial Images

    Get PDF

    Photocatalytic properties of tin oxide and antimony-doped tin oxide nanoparticles

    Get PDF
    For the first time it is shown that N-doped SnO2 nanoparticles photocatalyze directly the polymerization of the C=C bonds of (meth)acrylates under visible light illumination. These radical polymerizations also occur when these particles are doped with Sb and when the surfaces of these particles are grafted with methacrylate (MPS) groups. During irradiation with visible or UV light the position and/or intensity of the plasmon band absorption of these nanoparticles are always changed, suggesting that the polymerization starts by the transfer of an electron from the conduction band of the particle to the (meth)acrylate C=C bond. By using illumination wavelengths with a very narrow band width we determined the influence of the incident wavelength of light, the Sb- and N-doping, and the methacrylate (MPS) surface grafting on the quantum efficiencies for the initiating radical formation (F) and on the polymer and particle network formation. The results are explained by describing the effects of Sb-doping, N-doping, and/or methacrylate surface grafting on the band gaps, energy level distributions, and surface group reactivities of these nanoparticles. N-doped (MPS grafted) SnO2 (Sb = 0%) nanoparticles are new attractive photocatalysts under visible as well as UV illumination

    The scaling dimension of low lying Dirac eigenmodes and of the topological charge density

    Full text link
    As a quantitative measure of localization, the inverse participation ratio of low lying Dirac eigenmodes and topological charge density is calculated on quenched lattices over a wide range of lattice spacings and volumes. Since different topological objects (instantons, vortices, monopoles, and artifacts) have different co-dimension, scaling analysis provides information on the amount of each present and their correlation with the localization of low lying eigenmodes.Comment: Lattice2004(topology), Fermilab, June 21 - 26, 2004; 3 pages, 3 figure
    • …
    corecore