51 research outputs found

    Multifocus HDR VIS/NIR hyperspectral imaging and its application to works of art

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    The authors would like to thank Mr. Francisco Fernández Fábregas, owner of the Transfiguration of Christ for allowing us the privilege of studying this painting. We also acknowledge the collaboration of Angela Tate.This paper presents a complete framework for capturing and processing hyperspectral reflectance images of artworks in situ, using a hyperspectral line scanner. These capturing systems are commonly used in laboratory conditions synchronized with scanning stages specifically designed for planar surfaces. However, when the intended application domain does not allow for image capture in these controlled conditions, achieving useful spectral reflectance image data can be a very challenging task (due to uncontrolled illumination, high-dynamic range (HDR) conditions in the scene, and the influence of chromatic aberration on the image quality, among other factors). We show, for the first time, all the necessary steps in the image capturing and post-processing in order to obtain high-quality HDR-based reflectance in the visible and near infrared, directly from the data captured by using a hyperspectral line scanner coupled to a rotating tripod. Our results show that the proposed method outperforms the normal capturing process in terms of dynamic range, color and spectral accuracy. To demonstrate the potential interest of this processing strategy for on-site analysis of artworks, we applied it to the study of a vintage copy of the famous painting “Transfiguration” by Raphael, as well as a facsimile of “The Golden Haggadah” from the British Library of London. The second piece has been studied for the identification of highly reflective gold-foil covered areas.Spanish Ministry of Economy and Competitiveness, DPI2015-64571-R, ECQM2018-004952-

    Real-time ghost free HDR video stream generation using weight adaptation based method

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    International audienceTemporal exposure bracketing is a simple and low cost technique to generate a high dynamic range (HDR) images. This technique is widely used to recover the whole dynamic range of a scene by selecting the adequate number of low dynamic range (LDR) images to be fused. Temporal exposure bracketing technique is introduced to be used for static scenes and it cannot be applied directly for dynamic scenes since camera or object motion in bracketed exposures creates ghosts in the resulting HDR image. In this paper we propose a HDR algorithm modification to remove ghost artifact and we present a real-time implementation of this method on a smart camera (HDR video stream 1280 x 1024 at 60fps). We present experimental results to show the ghost removing efficiency of our implemented method

    Behavior-dependent specialization of identified hippocampal interneurons.

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    A large variety of GABAergic interneurons control information processing in the hippocampal circuits governing the formation of neuronal representations. Whether distinct hippocampal interneuron types contribute differentially to information processing during behavior is not known. We employed a new technique for recording and labeling interneurons and pyramidal cells in drug-free, freely moving rats. Recorded parvalbumin-expressing basket interneurons innervated somata and proximal pyramidal cell dendrites, whereas nitric oxide synthase- and neuropeptide Y-expressing ivy cells provided synaptic and extrasynaptic dendritic modulation. Basket and ivy cells showed distinct spike-timing dynamics, firing at different rates and times during theta and ripple oscillations. Basket, but not ivy, cells changed their firing rates during movement, sleep and quiet wakefulness, suggesting that basket cells coordinate cell assemblies in a behavioral state-contingent manner, whereas persistently firing ivy cells might control network excitability and homeostasis. Different interneuron types provide GABA to specific subcellular domains at defined times and rates, thereby differentially controlling network activity during behavior

    Bilan avant le traitement chirurgical d’un prolapsus génital : Recommandations pour la pratique clinique

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    International audienceINTRODUCTION:The issue addressed in this chapter of recommendations is: What is the clinical and para-clinical assessment to achieve in women with genital prolapse and for whom surgical treatment has been decided. What are the clinical elements of the examination that must be taken into account as a risk factor of failure or relapse after surgery, in order to anticipate and evaluate possible surgical difficulties, and to move towards a preferred surgical technique?MATERIAL AND METHODS:This work is based on a systematic review of the literature (PubMed, Medline, Cochrane Library, Cochrane Database of Systemactic Reviews, EMBASE) for meta-analyzes, randomized trials, registries, literature reviews, controlled studies and major not controlled studies, published on the subject. Its implementation has followed the methodology of the HAS on the recommendations for clinical practice, with a scientific argument (with the level of evidence, NP) and a recommendation grade (A, B, C, and professional agreement [AP]).RESULTS:It suits first of all to describe prolapse, by clinical examination, helped, if needed, by a supplement of imagery if clinical examination data are insufficient or in case of discrepancy between the functional signs and clinical anomalies found, or in case of doubt in associated pathology. It suits to look relapse risk factors (high grade prolapse) and postoperative complications risk factors (risk factors for prothetic exposure, surgical approach difficulties, pelvic pain syndrome with hypersensitivity) to inform the patient and guide the therapeutic choice. Urinary functional disorders associated with prolapse (urinary incontinence, overactive bladder, dysuria, urinary tract infection, upper urinary tract impact) will be search and evaluated by interview and clinical examination and by a flowmeter with measurement of the post voiding residue, a urinalysis, and renal-bladder ultrasound. In the presence of voiding disorders, it is appropriate to do their clinical and urodynamic evaluation. In the absence of any spontaneous or hidden urinary sign, there is so far no reason to recommend systematically urodynamic assessment. Anorectal symptoms associated with prolapse (irritable bowel syndrome, obstruction of defecation, fecal incontinence) should be search and evaluated. Before prolapse surgery, it is essential not to ignore gynecologic pathology.CONCLUSION:Before proposing a surgical cure of genital prolapse of women, it suits to achieve a clinical and paraclinical assessment to describe prolapse (anatomical structures involved, grade), to look for recurrence, difficulties approach and postoperative complications risk factors, and to appreciate the impact or the symptoms associated with prolapse (urinary, anorectal, gynecological, pelvic-perineal pain) to guide their evaluation and their treatment. © 2016 Published by Elsevier Masson SAS

    Behavior-dependent specialization of identified hippocampal interneurons.

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    A large variety of GABAergic interneurons control information processing in the hippocampal circuits governing the formation of neuronal representations. Whether distinct hippocampal interneuron types contribute differentially to information processing during behavior is not known. We employed a new technique for recording and labeling interneurons and pyramidal cells in drug-free, freely moving rats. Recorded parvalbumin-expressing basket interneurons innervated somata and proximal pyramidal cell dendrites, whereas nitric oxide synthase- and neuropeptide Y-expressing ivy cells provided synaptic and extrasynaptic dendritic modulation. Basket and ivy cells showed distinct spike-timing dynamics, firing at different rates and times during theta and ripple oscillations. Basket, but not ivy, cells changed their firing rates during movement, sleep and quiet wakefulness, suggesting that basket cells coordinate cell assemblies in a behavioral state-contingent manner, whereas persistently firing ivy cells might control network excitability and homeostasis. Different interneuron types provide GABA to specific subcellular domains at defined times and rates, thereby differentially controlling network activity during behavior

    On the Acquisition and Reproduction of Material Appearance

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    Currently, new technologies (e.g. 2.5D and 3D printing processes) progress at a fast pace in their capacity to (re)produce an ever-broader range of visual aspects. At the same time, a huge research effort is needed to achieve a comprehensive scientific model for the visual sensations we experience in front of an object in its surrounding. Thanks to the projects MUVApp: Measuring and Understanding Visual Appearance funded by the Research Council of Norway, and ApPEARS: Appearance Printing—European Advanced Research School recently granted by the European Union, significant progress is being made on various topics related with acquisition and reproduction of material appearance, and also on the very understanding of appearance. This paper presents recent, ongoing, and planned research in this exciting field, with a specific emphasis on the MUVApp project
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