18 research outputs found

    An efficient image retrieval scheme for colour enhancement of embedded and distributed surveillance images

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    From the past few years, the size of the data grows exponentially with respect to volume, velocity, and dimensionality due to wide spread use of embedded and distributed surveillance cameras for security reasons. In this paper, we have proposed an integrated approach for biometric-based image retrieval and processing which addresses the two issues. The first issue is related to the poor visibility of the images produced by the embedded and distributed surveillance cameras, and the second issue is concerned with the effective image retrieval based on the user query. This paper addresses the first issue by proposing an integrated image enhancement approach based on contrast enhancement and colour balancing methods. The contrast enhancement method is used to improve the contrast, while the colour balancing method helps to achieve a balanced colour. Importantly, in the colour balancing method, a new process for colour cast adjustment is introduced which relies on statistical calculation. It adjusts the colour cast and maintains the luminance of the image. The integrated image enhancement approach is applied to the enhancement of low quality images produced by surveillance cameras. The paper addresses the second issue relating to image retrieval by proposing a content-based image retrieval approach. The approach is based on the three features extraction methods namely colour, texture and shape. Colour histogram is used to extract the colour features of an image. Gabor filter is used to extract the texture features and the moment invariant is used to extract the shape features of an image. The use of these three algorithms ensures that the proposed image retrieval approach produces results which are highly relevant to the content of an image query, by taking into account the three distinct features of the image and the similarity metrics based on Euclidean measure. In order to retrieve the most relevant images, the proposed approach also employs a set of fuzzy heuristics to improve the quality of the results further. The result

    Correlation of financial markets in times of crisis

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    Using the eigenvalues and eigenvectors of correlations matrices of some of the main financial market indices in the world, we show that high volatility of markets is directly linked with strong correlations between them. This means that markets tend to behave as one during great crashes. In order to do so, we investigate several financial market crises that occurred in the years 1987 (Black Monday), 1989 (Russian crisis), 2001 (Burst of the dot-com bubble and September 11), and 2008 (Subprime Mortgage Crisis), which mark some of the largest downturns of financial markets in the last three decades.Comment: 33 pages, 46 figure

    Changes in functional characteristics of starch during water caltrop (Trapa Quadrispinosa Roxb.) growth.

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    [[abstract]]This study was carried out to establish the changes of physicochemical properties of Taiwan’s water caltrop (Trapa Quadrispinosa Roxb.) starch at various stages of maturity during growth. Investigations showed that the dry matter and starch contents of water caltrop increased from 9.7% to 25.61% and from 49.4% to 79.4% (d.b.), respectively, as growth progressed (from 14th to 42nd day after fruit development). The shape of the starch granules was smooth, oval and poly-angular during the growth period. The granule size of starch increased with increase of physiological age, ranging from 19.4 μm to 32.2 μm. The X-ray diffraction patterns could be classified as a typical A-type crystalline structure. Swelling power and solubility of water caltrop starch increased with increases of growth time. Starches obtained from water caltrop at the early stage exhibited a lower gelatinization temperature (To, Tp, Tc) and gelatinization enthalpy (ΔH) than did the late stage of maturity. The rapid viscosity analyzer (RVA) parameters suggested that water caltrop starch paste had a low breakdown, and appeared to be thermo-stable, at the early harvest time. The pasting temperature, peak viscosity, final viscosity and setback value of water caltrop starch increased as growth progressed. Different starch granular size and amylose content could be the major factors influencing starch physicochemical properties during maturity

    Branch Retinal Artery Occlusion Caused by Toxoplasmosis in an Adolescent

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    Purpose: Branch retinal artery occlusion (BRAO), while not uncommon in elderly patient populations, is rare in children and adolescents. We report a case of a BRAO secondary to toxoplasmosis in this demographic. Case: A previously healthy 17-year-old male developed a unilateral BRAO in conjunction with inflammation and increased intraocular pressure. Family history was positive for cerebrovascular accidents in multiple family members at relatively young ages. The patient had a hypercoagulable workup as well as a cardiovascular workup which were both normal. A rheumatologic workup was unremarkable. By 3 weeks, a patch of retinitis was more easily distinguished from the BRAO and the diagnosis of ocular toxoplasmosis was made. Treatment was started with prednisone and azithromycin with subsequent improvement in vision. Toxoplasma antibody levels were elevated for IgG and negative for IgM, IgA, and IgE. The etiology of the BRAO was attributed to ocular toxoplasmosis. Conclusions: Vascular occlusions are rare in toxoplasmosis. This is the third case report of a BRAO in a patient in the pediatric population. The diagnosis of ocular toxoplasmosis should be considered in young patients with retinal artery occlusions associated with inflammation
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