77 research outputs found

    Image Enhancement through Denoising and Retrieval of Vegetation Parameters from Landsat8

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    This paper proposed the enhancement of Landsat8 imagery through an Un-decimated Dual-Tree Complex Wavelet Transform (UDT-CWT) based denoising method and modified homographic filter for edge preservation. This work has been extended by estimating several vegetation parameters like Normalized Difference of Vegetation Index (NDVI), Green Normalized Difference Vegetation Index (GNDVI), Modified Soil Adjusted Vegetation Index (MASVI), and Soil & Atmospherically Resistant Vegetation Index (SARVI). Once the estimation of these parameters was done, the effect of noise was verified. Wavelet decomposes the image into frequency subbands and de-noises each subband separately. These subbands help to increase the resolution. The general problem of the homomorphic filter is that it doesn’t enhance the Low-frequency components which also play a key role in estimating Vegetation Indices (VI).So it was modified to enhance the high-frequency components as well as low-frequency details. Monitoring of vegetation parameters using remote sensing is one of the prominent ways in the estimation of crop yield, Land Use Land Cover (LULC), Water resource management, Drought management, etc. The high-resolution image is more preferable than moderate resolution image to retrieve VI. Image denoising and enhancing the spatial resolution helps to retrieve the parameters well and accurate. The proposed algorithm was working on the images of Landsat8

    State of the Art in Face Recognition

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    Notwithstanding the tremendous effort to solve the face recognition problem, it is not possible yet to design a face recognition system with a potential close to human performance. New computer vision and pattern recognition approaches need to be investigated. Even new knowledge and perspectives from different fields like, psychology and neuroscience must be incorporated into the current field of face recognition to design a robust face recognition system. Indeed, many more efforts are required to end up with a human like face recognition system. This book tries to make an effort to reduce the gap between the previous face recognition research state and the future state

    Automatic Spatiotemporal Analysis of Cardiac Image Series

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    RÉSUMÉ À ce jour, les maladies cardiovasculaires demeurent au premier rang des principales causes de dĂ©cĂšs en AmĂ©rique du Nord. Chez l’adulte et au sein de populations de plus en plus jeunes, la soi-disant Ă©pidĂ©mie d’obĂ©sitĂ© entraĂźnĂ©e par certaines habitudes de vie tels que la mauvaise alimentation, le manque d’exercice et le tabagisme est lourde de consĂ©quences pour les personnes affectĂ©es, mais aussi sur le systĂšme de santĂ©. La principale cause de morbiditĂ© et de mortalitĂ© chez ces patients est l’athĂ©rosclĂ©rose, une accumulation de plaque Ă  l’intĂ©rieur des vaisseaux sanguins Ă  hautes pressions telles que les artĂšres coronaires. Les lĂ©sions athĂ©rosclĂ©rotiques peuvent entraĂźner l’ischĂ©mie en bloquant la circulation sanguine et/ou en provoquant une thrombose. Cela mĂšne souvent Ă  de graves consĂ©quences telles qu’un infarctus. Outre les problĂšmes liĂ©s Ă  la stĂ©nose, les parois artĂ©rielles des rĂ©gions criblĂ©es de plaque augmentent la rigiditĂ© des parois vasculaires, ce qui peut aggraver la condition du patient. Dans la population pĂ©diatrique, la pathologie cardiovasculaire acquise la plus frĂ©quente est la maladie de Kawasaki. Il s’agit d’une vasculite aigĂŒe pouvant affecter l’intĂ©gritĂ© structurale des parois des artĂšres coronaires et mener Ă  la formation d’anĂ©vrismes. Dans certains cas, ceux-ci entravent l’hĂ©modynamie artĂ©rielle en engendrant une perfusion myocardique insuffisante et en activant la formation de thromboses. Le diagnostic de ces deux maladies coronariennes sont traditionnellement effectuĂ©s Ă  l’aide d’angiographies par fluoroscopie. Pendant ces examens paracliniques, plusieurs centaines de projections radiographiques sont acquises en sĂ©ries suite Ă  l’infusion artĂ©rielle d’un agent de contraste. Ces images rĂ©vĂšlent la lumiĂšre des vaisseaux sanguins et la prĂ©sence de lĂ©sions potentiellement pathologiques, s’il y a lieu. Parce que les sĂ©ries acquises contiennent de l’information trĂšs dynamique en termes de mouvement du patient volontaire et involontaire (ex. battements cardiaques, respiration et dĂ©placement d’organes), le clinicien base gĂ©nĂ©ralement son interprĂ©tation sur une seule image angiographique oĂč des mesures gĂ©omĂ©triques sont effectuĂ©es manuellement ou semi-automatiquement par un technicien en radiologie. Bien que l’angiographie par fluoroscopie soit frĂ©quemment utilisĂ© partout dans le monde et souvent considĂ©rĂ© comme l’outil de diagnostic “gold-standard” pour de nombreuses maladies vasculaires, la nature bidimensionnelle de cette modalitĂ© d’imagerie est malheureusement trĂšs limitante en termes de spĂ©cification gĂ©omĂ©trique des diffĂ©rentes rĂ©gions pathologiques. En effet, la structure tridimensionnelle des stĂ©noses et des anĂ©vrismes ne peut pas ĂȘtre pleinement apprĂ©ciĂ©e en 2D car les caractĂ©ristiques observĂ©es varient selon la configuration angulaire de l’imageur. De plus, la prĂ©sence de lĂ©sions affectant les artĂšres coronaires peut ne pas reflĂ©ter la vĂ©ritable santĂ© du myocarde, car des mĂ©canismes compensatoires naturels (ex. vaisseaux----------ABSTRACT Cardiovascular disease continues to be the leading cause of death in North America. In adult and, alarmingly, ever younger populations, the so-called obesity epidemic largely driven by lifestyle factors that include poor diet, lack of exercise and smoking, incurs enormous stresses on the healthcare system. The primary cause of serious morbidity and mortality for these patients is atherosclerosis, the build up of plaque inside high pressure vessels like the coronary arteries. These lesions can lead to ischemic disease and may progress to precarious blood flow blockage or thrombosis, often with infarction or other severe consequences. Besides the stenosis-related outcomes, the arterial walls of plaque-ridden regions manifest increased stiffness, which may exacerbate negative patient prognosis. In pediatric populations, the most prevalent acquired cardiovascular pathology is Kawasaki disease. This acute vasculitis may affect the structural integrity of coronary artery walls and progress to aneurysmal lesions. These can hinder the blood flow’s hemodynamics, leading to inadequate downstream perfusion, and may activate thrombus formation which may lead to precarious prognosis. Diagnosing these two prominent coronary artery diseases is traditionally performed using fluoroscopic angiography. Several hundred serial x-ray projections are acquired during selective arterial infusion of a radiodense contrast agent, which reveals the vessels’ luminal area and possible pathological lesions. The acquired series contain highly dynamic information on voluntary and involuntary patient movement: respiration, organ displacement and heartbeat, for example. Current clinical analysis is largely limited to a single angiographic image where geometrical measures will be performed manually or semi-automatically by a radiological technician. Although widely used around the world and generally considered the gold-standard diagnosis tool for many vascular diseases, the two-dimensional nature of this imaging modality is limiting in terms of specifying the geometry of various pathological regions. Indeed, the 3D structures of stenotic or aneurysmal lesions may not be fully appreciated in 2D because their observable features are dependent on the angular configuration of the imaging gantry. Furthermore, the presence of lesions in the coronary arteries may not reflect the true health of the myocardium, as natural compensatory mechanisms may obviate the need for further intervention. In light of this, cardiac magnetic resonance perfusion imaging is increasingly gaining attention and clinical implementation, as it offers a direct assessment of myocardial tissue viability following infarction or suspected coronary artery disease. This type of modality is plagued, however, by motion similar to that present in fluoroscopic imaging. This issue predisposes clinicians to laborious manual intervention in order to align anatomical structures in sequential perfusion frames, thus hindering automation o

    Automatic Spatiotemporal Analysis of Cardiac Image Series

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    RÉSUMÉ À ce jour, les maladies cardiovasculaires demeurent au premier rang des principales causes de dĂ©cĂšs en AmĂ©rique du Nord. Chez l’adulte et au sein de populations de plus en plus jeunes, la soi-disant Ă©pidĂ©mie d’obĂ©sitĂ© entraĂźnĂ©e par certaines habitudes de vie tels que la mauvaise alimentation, le manque d’exercice et le tabagisme est lourde de consĂ©quences pour les personnes affectĂ©es, mais aussi sur le systĂšme de santĂ©. La principale cause de morbiditĂ© et de mortalitĂ© chez ces patients est l’athĂ©rosclĂ©rose, une accumulation de plaque Ă  l’intĂ©rieur des vaisseaux sanguins Ă  hautes pressions telles que les artĂšres coronaires. Les lĂ©sions athĂ©rosclĂ©rotiques peuvent entraĂźner l’ischĂ©mie en bloquant la circulation sanguine et/ou en provoquant une thrombose. Cela mĂšne souvent Ă  de graves consĂ©quences telles qu’un infarctus. Outre les problĂšmes liĂ©s Ă  la stĂ©nose, les parois artĂ©rielles des rĂ©gions criblĂ©es de plaque augmentent la rigiditĂ© des parois vasculaires, ce qui peut aggraver la condition du patient. Dans la population pĂ©diatrique, la pathologie cardiovasculaire acquise la plus frĂ©quente est la maladie de Kawasaki. Il s’agit d’une vasculite aigĂŒe pouvant affecter l’intĂ©gritĂ© structurale des parois des artĂšres coronaires et mener Ă  la formation d’anĂ©vrismes. Dans certains cas, ceux-ci entravent l’hĂ©modynamie artĂ©rielle en engendrant une perfusion myocardique insuffisante et en activant la formation de thromboses. Le diagnostic de ces deux maladies coronariennes sont traditionnellement effectuĂ©s Ă  l’aide d’angiographies par fluoroscopie. Pendant ces examens paracliniques, plusieurs centaines de projections radiographiques sont acquises en sĂ©ries suite Ă  l’infusion artĂ©rielle d’un agent de contraste. Ces images rĂ©vĂšlent la lumiĂšre des vaisseaux sanguins et la prĂ©sence de lĂ©sions potentiellement pathologiques, s’il y a lieu. Parce que les sĂ©ries acquises contiennent de l’information trĂšs dynamique en termes de mouvement du patient volontaire et involontaire (ex. battements cardiaques, respiration et dĂ©placement d’organes), le clinicien base gĂ©nĂ©ralement son interprĂ©tation sur une seule image angiographique oĂč des mesures gĂ©omĂ©triques sont effectuĂ©es manuellement ou semi-automatiquement par un technicien en radiologie. Bien que l’angiographie par fluoroscopie soit frĂ©quemment utilisĂ© partout dans le monde et souvent considĂ©rĂ© comme l’outil de diagnostic “gold-standard” pour de nombreuses maladies vasculaires, la nature bidimensionnelle de cette modalitĂ© d’imagerie est malheureusement trĂšs limitante en termes de spĂ©cification gĂ©omĂ©trique des diffĂ©rentes rĂ©gions pathologiques. En effet, la structure tridimensionnelle des stĂ©noses et des anĂ©vrismes ne peut pas ĂȘtre pleinement apprĂ©ciĂ©e en 2D car les caractĂ©ristiques observĂ©es varient selon la configuration angulaire de l’imageur. De plus, la prĂ©sence de lĂ©sions affectant les artĂšres coronaires peut ne pas reflĂ©ter la vĂ©ritable santĂ© du myocarde, car des mĂ©canismes compensatoires naturels (ex. vaisseaux----------ABSTRACT Cardiovascular disease continues to be the leading cause of death in North America. In adult and, alarmingly, ever younger populations, the so-called obesity epidemic largely driven by lifestyle factors that include poor diet, lack of exercise and smoking, incurs enormous stresses on the healthcare system. The primary cause of serious morbidity and mortality for these patients is atherosclerosis, the build up of plaque inside high pressure vessels like the coronary arteries. These lesions can lead to ischemic disease and may progress to precarious blood flow blockage or thrombosis, often with infarction or other severe consequences. Besides the stenosis-related outcomes, the arterial walls of plaque-ridden regions manifest increased stiffness, which may exacerbate negative patient prognosis. In pediatric populations, the most prevalent acquired cardiovascular pathology is Kawasaki disease. This acute vasculitis may affect the structural integrity of coronary artery walls and progress to aneurysmal lesions. These can hinder the blood flow’s hemodynamics, leading to inadequate downstream perfusion, and may activate thrombus formation which may lead to precarious prognosis. Diagnosing these two prominent coronary artery diseases is traditionally performed using fluoroscopic angiography. Several hundred serial x-ray projections are acquired during selective arterial infusion of a radiodense contrast agent, which reveals the vessels’ luminal area and possible pathological lesions. The acquired series contain highly dynamic information on voluntary and involuntary patient movement: respiration, organ displacement and heartbeat, for example. Current clinical analysis is largely limited to a single angiographic image where geometrical measures will be performed manually or semi-automatically by a radiological technician. Although widely used around the world and generally considered the gold-standard diagnosis tool for many vascular diseases, the two-dimensional nature of this imaging modality is limiting in terms of specifying the geometry of various pathological regions. Indeed, the 3D structures of stenotic or aneurysmal lesions may not be fully appreciated in 2D because their observable features are dependent on the angular configuration of the imaging gantry. Furthermore, the presence of lesions in the coronary arteries may not reflect the true health of the myocardium, as natural compensatory mechanisms may obviate the need for further intervention. In light of this, cardiac magnetic resonance perfusion imaging is increasingly gaining attention and clinical implementation, as it offers a direct assessment of myocardial tissue viability following infarction or suspected coronary artery disease. This type of modality is plagued, however, by motion similar to that present in fluoroscopic imaging. This issue predisposes clinicians to laborious manual intervention in order to align anatomical structures in sequential perfusion frames, thus hindering automation o

    Component Decomposition-Based Hyperspectral Resolution Enhancement for Mineral Mapping

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    Combining both spectral and spatial information with enhanced resolution provides not only elaborated qualitative information on surfacing mineralogy but also mineral interactions of abundance, mixture, and structure. This enhancement in the resolutions helps geomineralogic features such as small intrusions and mineralization become detectable. In this paper, we investigate the potential of the resolution enhancement of hyperspectral images (HSIs) with the guidance of RGB images for mineral mapping. In more detail, a novel resolution enhancement method is proposed based on component decomposition. Inspired by the principle of the intrinsic image decomposition (IID) model, the HSI is viewed as the combination of a reflectance component and an illumination component. Based on this idea, the proposed method is comprised of several steps. First, the RGB image is transformed into the luminance component, blue-difference and red-difference chroma components (YCbCr), and the luminance channel is considered as the illumination component of the HSI with an ideal high spatial resolution. Then, the reflectance component of the ideal HSI is estimated with the downsampled HSI image and the downsampled luminance channel. Finally, the HSI with high resolution can be reconstructed by utilizing the obtained illumination and the reflectance components. Experimental results verify that the fused results can successfully achieve mineral mapping, producing better results qualitatively and quantitatively over single sensor data
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