993,420 research outputs found

    Error resilience analysis of wireless image transmission using JPEG, JPEG 2000 and JPWL

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    The wireless extension of the JPEG 2000 standard formally known as JPWL is the newest international standard for still image compression. Different from all previous standards, this new standard was created specifically for wireless imaging applications. This paper examines the error resilience performance of the JPEG, JPEG 2000 and JPWL standards in combating multi-path and fading impairments in Rayleigh fading channels. Comprehensive objective and subjective results are presented in relation to the error resilience performance of these three standards under various conditions. The major findings in this paper reveal that a CRC approach is not a viable option for protecting wireless image data when not used in conjunction with an efficient retransmission strategy. In addition, the Reed-Solomon error correction codes in JPWL provide strong protection for wireless image transmission. However, any stronger protection beyond RS(64,32) yields diminishing returns

    Cross-departmental initiative to produce an online Image Library for staff at the National Gallery, London

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    The Image Gallery project ran from June 2007 and was launched via a tab in the staff Intranet in April 2008. It was a collaboration between the Photographic Department and the Libraries and Archive Department, but also engaged image users across the Gallery. The aim of the Image Gallery was to provide photographs taken of Gallery activities and events, images from the Photographic Archive, and works of art from other museums and galleries, not the works of art in the National Gallery's collection. This paper discusses project management standards, data standards, creation of a subject index, design of the interface, and user testing

    Map accuracy requirements: The cartographic potential of satellite image data

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    Cartographic products fall into a variety of classes: topographic maps that are concerned with planimetric information and elevations or heights; thematic maps, which might be used for geology, vegetation, water, or to display these subjects; digital elevation maps that would be produced from digital terrain data; and finally image maps. In terms of satellite applications, thematic maps and image maps are emphasized. The objectives are to consider, first, if resolution will be adequate for the identification of control and for the compilation of map products. Then, second, to define map accuracy standards and to determine the potential for meeting these standards with image data from the film camera, scanner and linear array systems of the 1980s

    Hausdorff-Distance Enhanced Matching of Scale Invariant Feature Transform Descriptors in Context of Image Querying

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    Reliable and effective matching of visual descriptors is a key step for many vision applications, e.g. image retrieval. In this paper, we propose to integrate the Hausdorff distance matching together with our pairing algorithm, in order to obtain a robust while computationally efficient process of matching feature descriptors for image-to-image querying in standards datasets. For this purpose, Scale Invariant Feature Transform (SIFT) descriptors have been matched using our presented algorithm, followed by the computation of our related similarity measure. This approach has shown excellent performance in both retrieval accuracy and speed

    Magnetic tape

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    The move to visualization and image processing in data systems is increasing the demand for larger and faster mass storage systems. The technology of choice is magnetic tape. This paper briefly reviews the technology past, present, and projected. A case is made for standards and the value of the standards to users

    Perturbation of the Eigenvectors of the Graph Laplacian: Application to Image Denoising

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    The original contributions of this paper are twofold: a new understanding of the influence of noise on the eigenvectors of the graph Laplacian of a set of image patches, and an algorithm to estimate a denoised set of patches from a noisy image. The algorithm relies on the following two observations: (1) the low-index eigenvectors of the diffusion, or graph Laplacian, operators are very robust to random perturbations of the weights and random changes in the connections of the patch-graph; and (2) patches extracted from smooth regions of the image are organized along smooth low-dimensional structures in the patch-set, and therefore can be reconstructed with few eigenvectors. Experiments demonstrate that our denoising algorithm outperforms the denoising gold-standards
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