39 research outputs found

    Recent Advances in Watermarking for Scalable Video Coding

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    Recent Advances in Region-of-interest Video Coding

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    Heuristic Principles and Differential Judgments in the Assessment of Information Quality

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    Information quality (IQ) is a multidimensional construct and includes dimensions such as accuracy, completeness, objectivity, and representation that are difficult to measure. Recently, research has shown that independent assessors who rated IQ yielded high inter-rater agreement for some information quality dimensions as opposed to others. In this paper, we explore the reasons that underlie the differences in the “measurability” of IQ. Employing Gigerenzer’s “building blocks” framework, we conjecture that the feasibility of using a set of heuristic principles consistently when assessing different dimensions of IQ is a key factor driving inter-rater agreement in IQ judgments. We report on two studies. In the first study, we qualitatively explored the manner in which participants applied the heuristic principles of search rules, stopping rules, and decision rules in assessing the IQ dimensions of accuracy, completeness, objectivity, and representation. In the second study, we investigated the extent to which participants could reach an agreement in rating the quality of Wikipedia articles along these dimensions. Our findings show an alignment between the consistent application of heuristic principles and inter-rater agreement levels found on particular dimensions of IQ judgments. Specifically, on the dimensions of completeness and representation, assessors applied the heuristic principles consistently and tended to agree in their ratings, whereas, on the dimensions of accuracy and objectivity, they not apply the heuristic principles in a uniform manner and inter-rater agreement was relatively low. We discuss our findings implications for research and practice

    Oversampling requirements for pixelated-imager systems

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    Abstract. The image quality resulting from a 2-D image-sampling process by an array of pixels is described. The description is based on a Fourier transformation of the Wigner-Seitz cell, which transforms a unit cell of the sampling lattice in the spatial domain into a bandwidth cell in the spatial-frequency domain. The area of the resulting bandwidth cell is a quantitative measure of the image fidelity of the sampling process. We compare the image-quality benefits of three different oversampling geometries in terms of the modulation transfer function (MTF) as a function of the amount of oversampling used. © 1999 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(99
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