Relevant bibliographies by topics / Contourlet transform

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Book chapters
  4. Conference papers

Academic literature on the topic 'Contourlet transform'

Author: Grafiati
Published: 4 June 2021
Last updated: 2 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Contourlet transform.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Contourlet transform"

1

Hamdi, Med. "A Comparative Study in Wavelets, Curvelets and Contourlets as Denoising biomedical Images." Image Processing & Communications 16, no. 3-4 (January 1, 2011): 13–20. http://dx.doi.org/10.2478/v10248-012-0007-1.

Full text
Abstract:
A Comparative Study in Wavelets, Curvelets and Contourlets as Denoising biomedical ImagesA special member of the emerging family of multi scale geometric transforms is the contourlet transform which was developed in the last few years in an attempt to overcome inherent limitations of traditional multistage representations such as curvelets and wavelets. The biomedical images were denoised using firstly wavelet than curvelets and finally contourlets transform and results are presented in this paper. It has been found that the contourlets transform outperforms the curvelets and wavelet transform in terms of signal noise ratio
APA, Harvard, Vancouver, ISO, and other styles
2

Han, Liang, Wen-li Zhang, Xiujuan Pu, Wanqi Cheng, and Xia Liu. "Optical nonsubsampled contourlet transform." Applied Optics 55, no. 27 (September 20, 2016): 7726. http://dx.doi.org/10.1364/ao.55.007726.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Cao, Min, Shan Shan Tan, and Quan Fei Shen. "Study on Image Fusion Model Based on HIS Transform and Nonsubsampled Contourlet Transform." Key Engineering Materials 500 (January 2012): 659–65. http://dx.doi.org/10.4028/www.scientific.net/kem.500.659.

Full text
Abstract:
After analysising the principle of nonsubsampled contourlet transform, the image fusion model based on HIS transform and nonsubsampled contourlet transform is proposed. By taking of ALOS image as an example, the image fusion of multi-spectral band and panchromatic band at the same time is carried out by different fusion methods such as the method combining HIS transform and nonsubsampled contourlet transform (NSCT), HIS transform fusion method, principal component analysis (PCA), Brovey and static wavelet transform (SWT). By calculating the quantitative evaluation indicators of the different fused image, it is conclued that the fusion effection of static wavelet transform fusion method and nonsubsampled contourlet transform fusion method is better than the common methods such as HIS transform, principal component analysis and Brovey. In particular, the image fusion effection of nonsubsampled contourlet transform method, which betterly maintains the image spectral information while improving image spatial resolution at the same time, is superior than the fusion evaluation of static wavelet transform fusion method.
APA, Harvard, Vancouver, ISO, and other styles
4

Chen, Xin Wu, and Zhan Qing Ma. "Material Texture Retrieval Using Contourlet-2.3 and Three Statistical Features." Advanced Materials Research 233-235 (May 2011): 2495–98. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.2495.

Full text
Abstract:
To improve the retrieval rate of contourlet transform texture retrieval system, a contourlet-2.3 transform based retrieval system was proposed. Six different features, including mean, standard deviation, absolute mean energy, L2 energy, skewness and kurtosis contributions to retrieval rates were examined. Based on the single feature ability in retrieval system, a contourlet-2.3 retrieval system was proposed. The feature vectors were constructed by cascading the standard deviation, absolute mean energy and kurtosis of each sub-band contourlet coefficients and the similarity measure used here is Canberra distance. Experimental results on 109 brodatz texture images show that the new retrieval algorithm can lead to a higher retrieval rate than several contourlet transform retrieval systems including the original contourlet transform, non-subsampled contourlet transform under the same structure.
APA, Harvard, Vancouver, ISO, and other styles
5

Vafaie, Sepideh, and Eysa Salajegheh. "Comparisons of wavelets and contourlets for vibration-based damage identification in the plate structures." Advances in Structural Engineering 22, no. 7 (January 20, 2019): 1672–84. http://dx.doi.org/10.1177/1369433218824903.

Full text
Abstract:
The objective of the present study is to compare a new approach based on contourlet transform and a traditional method based on wavelet transform to demonstrate curve damages in plate structures. The contourlet transform approach, as a novel two-dimensional development of wavelet transform, was extended to deal with inherent restrictions of wavelets. According to previous studies, wavelets have indicated poor performance to detect curve damages due to its basic elements. Therefore, this study utilized contourlet transform as a new method having an efficient performance to display this kind of discontinuities. In this research, contourlet transform and wavelet transform have been applied to a plate using four fixed boundary conditions including circle damages with arbitrary specifications and location in order to demonstrate their performance in damage identification. Comparing damage shape attained from contourlet transform and wavelet transform, it was revealed that contourlet transform could be utilized as an accessible and useful technique to detect damage with curvature.
APA, Harvard, Vancouver, ISO, and other styles
6

Luo, Zi Juan, and Shuai Ding. "Image Fusion Algorithm Based on Nonsubsampled Contourlet Transform." Applied Mechanics and Materials 401-403 (September 2013): 1381–84. http://dx.doi.org/10.4028/www.scientific.net/amm.401-403.1381.

Full text
Abstract:
t is mostly difficult to get an image that contains all relevant objects in focus, because of the limited depth-of-focus of optical lenses. The multifocus image fusion method can solve the problem effectively. Nonsubsampled Contourlet transform has varying directions and multiple scales. When the Nonsubsampled contourlet transform is introduced to image fusion, the characteristics of original images are taken better and more information for fusion is obtained. A new method of multi-focus image fusion based on Nonsubsampled contourlet transform (NSCT) with the fusion rule of region statistics is proposed in this paper. Firstly, different focus images are decomposed using Nonsubsampled contourlet transform. Then low-bands are integrated using the weighted average, high-bands are integrated using region statistics rule. Next the fused image will be obtained by inverse Nonsubsampled contourlet transform. Finally the experimental results are showed and compared with those of method based on Contourlet transform. Experiments show that the approach can achieve better results than the method based on contourlet transform.
APA, Harvard, Vancouver, ISO, and other styles
7

Guo, Zhen, and Xin Wu Chen. "Contourlet-1.3 Texture Retrieval with Energy, Standard Deviation and Kurtosis." Applied Mechanics and Materials 446-447 (November 2013): 1347–52. http://dx.doi.org/10.4028/www.scientific.net/amm.446-447.1347.

Full text
Abstract:
Contourlet-1.3 transform has better performance in directional information representation than the original contourlet transform due to less artifacts and local frequency characteristics, and has been studied by us in retrieval systems and has been shown it is superior to contourlet ones at retrieval rate. In order to improve the retrieval rate further, a novel contourlet-1.3 transform based texture image retrieval system was proposed in this paper. In the system, sub-bands energy, standard deviation and kurtosis in contourlet domain were cascaded to form feature vectors, and the similarity measure function was Canberra distance. Experimental results show that this contourlet-1.3 transform based image retrieval system has higher retrieval rates about 7% to that of the contourlet transform with absolute mean sub-bands energy and standard deviations features under same system structure.
APA, Harvard, Vancouver, ISO, and other styles
8

Li, Xiang Ying, Rui Xue, Xin Wu Chen, and Wei Luo. "Contourlet-S Retrieval Algorithm Using Absolute Mean Energy and Kurtosis Features." Applied Mechanics and Materials 197 (September 2012): 473–76. http://dx.doi.org/10.4028/www.scientific.net/amm.197.473.

Full text
Abstract:
Contourlet transform has better performance in directional information representation than wavelet transform and has been studied by many researchers in retrieval systems and has been shown that it is superior to wavelet ones at retrieval rate. In order to improve the retrieval rate further, a contourlet-S transform based texture image retrieval system was proposed in this paper. In the system, the contourlet transform was constructed by non-subsampled Laplacian pyramid cascaded by critical subsampled directional filter banks, sub-bands absolute mean energy and kurtosis in contourlet-S domain are cascaded to form feature vectors, and the similarity metric is Canberra distance. Experimental results on 109 brodatz texture images show that using the features cascaded by absolute mean and kurtosis can lead to a higher retrieval rate than the combination of standard deviation and absolute mean which is most commonly used today under same dimension of feature vectors. contourlet-S transform based image retrieval system is superior to those of the original contourlet transform, non-subsampled contourlet system under the same system structure with same length of feature vectors, retrieval time and memory needed, contourlet-S decomposition structure parameters can make significant effects on retrieval rates, especially scale number.
APA, Harvard, Vancouver, ISO, and other styles
9

Ma, Jian Zhong, Xin Wu Chen, and Li Juan Zhong. "Contourlet-S Texture Image Retrieval System." Advanced Materials Research 433-440 (January 2012): 3408–12. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.3408.

Full text
Abstract:
Contourlet transform is better in direction information representation than wavelet transform which has been studied in retrieval systems and has been shown that it is superior to wavelet ones at retrieval rate. In order to improve the retrieval rate further, an anti-aliasing contourlet-S transform based texture image retrieval system was proposed. In this system, the contourlet transform was constructed by anti-aliasing non-subsampled Laplacian pyramid cascaded by critical sub-sampled directional filter banks, sub-bands energy and standard deviations in contourlet domain are cascaded to form feature vectors, and the similarity metric used here is Canberra distance. Experimental results show that contourlet-S transform based image retrieval system is superior to those of the original contourlet transform, and non-subsampled contourlet system under the same system structure with almost same dimension of feature vectors, retrieval time and memory needed; and contourlet decomposition structure parameters can make significant effects on retrieval rates, especially scale number. To improve the retrieval rate of this system, kurtosis in each sub-band coefficients can be incorporated in features at the cost of some higher dimension of feature vectors.
APA, Harvard, Vancouver, ISO, and other styles
10

Liu, Yu Xi, and Xin Wu Chen. "Semi-Subsampled Contourlet Retrieval Algorithm Using Three Statistical Features." Advanced Materials Research 433-440 (January 2012): 3117–23. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.3117.

Full text
Abstract:
In order to improve the retrieval rate of contourlet transform retrieval system, a semi-subsampled contourlet transform based texture image retrieval system was proposed. In the system, the contourlet transform was constructed by non-subsampled Laplacian pyramid cascaded by critical subsampled directional filter banks, sub-bands standard deviation, absolute mean energy and kurtosis in semi-subsampled contourlet domain are cascaded to form feature vectors, and the similarity metric is Canberra distance. Experimental results on 109 brodatz texture images show that using the three cascaded features can lead to a higher retrieval rate than the combination of standard deviation and absolute mean which is most commonly used today under same dimension of feature vectors. Semi-subsampled contourlet transform based image retrieval system is superior to those of the original contourlet transform, non-subsampled contourlet system under the same system structure with same length of feature vectors, retrieval time and memory needed, decomposition structure parameters can also make significant effects on retrieval rates, especially scale number.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Contourlet transform"

1

Hanzouli, Houda. "Analyse multi échelle et multi observation pour l'imagerie multi modale en oncologie." Thesis, Brest, 2016. http://www.theses.fr/2016BRES0126/document.

Full text
Abstract:
Ce travail s’inscrit dans le cadre du développement d’une médecine davantage personnalisée et préventive, pour laquelle la fusion d’informations multi modale et de différentes représentations d'une même modalité sont nécessaires afin d'aboutir à une quantification fiable des images médicales en oncologie. Dans cette étude nous présentons deux applications de traitement et d'analyse des images médicales: le débruitage des images TEP et la détermination des volumes anatomo-fonctionnels des tumeurs en imagerie multi modale TEP/TDM. Pour le débruitage des images TEP, nous avons mis en place une approche intitulée "WCD" permettant de bénéficier des caractéristiques complémentaires de la transformée en ondelettes et la transformée en Curvelets afin de mieux représenter les structures isotropiques et anisotropiques dans ces images, ce qui permet de réduire le bruit tout en minimisant les pertes d'informations utiles dans les images TEP. En ce qui concerne la deuxième application, nous avons proposé une méthode de segmentationTEP/TDM intitulée "WCHMT" permettant d'exploiter la spécificité des arbres de Markov caché de prendre en compte les dépendances statistiques entre l’ensemble des données. Ce modèle permet de gérer simultanément les propriétés complémentaires de l’imagerie fonctionnelle et l’imagerie morphologique dans un cadre unifié où les données sont représentées dans le domaine des Contourlets. Le débruitage en TEP a abouti à une hausse significative du rapport signal sur-bruit (SNR) en garantissant la moindre variation de l'intensité et du contraste local. Quant à la segmentation multimodale TEP/TDM, elle a démontré une bonne précision lors de la détermination du volume tumoral en terme du coefficient de Dice (DSC) avec le meilleur compromis entre la sensibilité (SE) et la valeur prédictive positive (PPV) par rapport à la vérité terrain
This thesis is a part of the development of more personalized and preventive medicine, for which a fusion of multi modal information and diverse representations of the same modality is needed in order to get accurate and reliable quantification of medical images in oncology. In this study we present two applications for image processing analysis: PET denoising and multimodal PET/CT tumor segmentation. The PET filtering approach called "WCD" take benefit from the complementary features of the wavelet and Curvelets transforms in order to better represent isotropic and anisotropic structures in PET images. This algorithm allows the reduction of the noise while minimizing the loss of useful information in PET images. The PET/CT tumor segmentation application is performed through a Markov model as a probabilistic quadtree graph namely a Hidden Markov Tree (HMT).Our motivation for using such a model is to provide fast computation, improved robustness and an effective interpretational framework for image analysis on oncology. Thanks to two efficient aspects (multi observation and multi resolution), when dealing with Hidden Markov Tree (HMT), we exploit joint statistical dependencies between hidden states to handle the whole data stack. This model called "WCHMT" take advantage of the high resolution of the anatomic imaging (CT) and the high contrast of the functional imaging (PET). The denoising approach led to the best trade-off between denoising quality and structure preservation with the least quantitative bias in absolute intensity recovery. PET/CT segmentation's results performed with WCHMT method has proven a reliable segmentation when providing high Dice Similarity Coeffcient (DSC) with the best trade-off between sensitivity (SE) and positive predictive value (PPV)
APA, Harvard, Vancouver, ISO, and other styles
2

Kaše, David. "Komprese obrazu pomocí vlnkové transformace." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2015. http://www.nusl.cz/ntk/nusl-234996.

Full text
Abstract:
This thesis deals with image compression using wavelet, contourlet and shearlet transformation. It starts with quick look at image compression problem a quality measurement. Next are presented basic concepts of wavelets, multiresolution analysis and scaling function and detailed look at each transform. Representatives of algorithms for coeficients coding are EZW, SPIHT and marginally EBCOT. In second part is described design and implementation of constructed library. Last part compare result of transforms with format JPEG 2000. Comparison resulted in determining type of image in which implemented contourlet and shearlet transform were more effective than wavelet. Format JPEG 2000 was not exceeded.
APA, Harvard, Vancouver, ISO, and other styles
3

Costa, Daniel Moura Martins da. "Ensemble baseado em métodos de Kernel para reconhecimento biométrico multimodal." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/100/100131/tde-28072016-190335/.

Full text
Abstract:
Com o avanço da tecnologia, as estratégias tradicionais para identificação de pessoas se tornaram mais suscetíveis a falhas, de forma a superar essas dificuldades algumas abordagens vêm sendo propostas na literatura. Dentre estas abordagens destaca-se a Biometria. O campo da Biometria abarca uma grande variedade de tecnologias usadas para identificar e verificar a identidade de uma pessoa por meio da mensuração e análise de aspectos físicos e/ou comportamentais do ser humano. Em função disso, a biometria tem um amplo campo de aplicações em sistemas que exigem uma identificação segura de seus usuários. Os sistemas biométricos mais populares são baseados em reconhecimento facial ou de impressões digitais. Entretanto, existem outros sistemas biométricos que utilizam a íris, varredura de retina, voz, geometria da mão e termogramas faciais. Nos últimos anos, o reconhecimento biométrico obteve avanços na sua confiabilidade e precisão, com algumas modalidades biométricas oferecendo bom desempenho global. No entanto, mesmo os sistemas biométricos mais avançados ainda enfrentam problemas. Recentemente, esforços têm sido realizados visando empregar diversas modalidades biométricas de forma a tornar o processo de identificação menos vulnerável a ataques. Biometria multimodal é uma abordagem relativamente nova para representação de conhecimento biométrico que visa consolidar múltiplas modalidades biométricas. A multimodalidade é baseada no conceito de que informações obtidas a partir de diferentes modalidades se complementam. Consequentemente, uma combinação adequada dessas informações pode ser mais útil que o uso de informações obtidas a partir de qualquer uma das modalidades individualmente. As principais questões envolvidas na construção de um sistema biométrico unimodal dizem respeito à definição das técnicas de extração de característica e do classificador. Já no caso de um sistema biométrico multimodal, além destas questões, é necessário definir o nível de fusão e a estratégia de fusão a ser adotada. O objetivo desta dissertação é investigar o emprego de ensemble para fusão das modalidades biométricas, considerando diferentes estratégias de fusão, lançando-se mão de técnicas avançadas de processamento de imagens (tais como transformada Wavelet, Contourlet e Curvelet) e Aprendizado de Máquina. Em especial, dar-se-á ênfase ao estudo de diferentes tipos de máquinas de aprendizado baseadas em métodos de Kernel e sua organização em arranjos de ensemble, tendo em vista a identificação biométrica baseada em face e íris. Os resultados obtidos mostraram que a abordagem proposta é capaz de projetar um sistema biométrico multimodal com taxa de reconhecimento superior as obtidas pelo sistema biométrico unimodal.
With the advancement of technology, traditional strategies for identifying people become more susceptible to failure, in order to overcome these difficulties some approaches have been proposed in the literature. Among these approaches highlights the Biometrics. The field of Biometrics encompasses a wide variety of technologies used to identify and verify the person\'s identity through the measurement and analysis of physiological and behavioural aspects of the human body. As a result, biometrics has a wide field of applications in systems that require precise identification of their users. The most popular biometric systems are based on face recognition and fingerprint matching. Furthermore, there are other biometric systems that utilize iris and retinal scan, speech, face, and hand geometry. In recent years, biometrics authentication has seen improvements in reliability and accuracy, with some of the modalities offering good performance. However, even the best biometric modality is facing problems. Recently, big efforts have been undertaken aiming to employ multiple biometric modalities in order to make the authentication process less vulnerable to attacks. Multimodal biometrics is a relatively new approach to biometrics representation that consolidate multiple biometric modalities. Multimodality is based on the concept that the information obtained from different modalities complement each other. Consequently, an appropriate combination of such information can be more useful than using information from single modalities alone. The main issues involved in building a unimodal biometric System concern the definition of the feature extraction technique and type of classifier. In the case of a multimodal biometric System, in addition to these issues, it is necessary to define the level of fusion and fusion strategy to be adopted. The aim of this dissertation is to investigate the use of committee machines to fuse multiple biometric modalities, considering different fusion strategies, taking into account advanced methods in machine learning. In particular, it will give emphasis to the analyses of different types of machine learning methods based on Kernel and its organization into arrangements committee machines, aiming biometric authentication based on face, fingerprint and iris. The results showed that the proposed approach is capable of designing a multimodal biometric System with recognition rate than those obtained by the unimodal biometrics Systems.
APA, Harvard, Vancouver, ISO, and other styles
4

Bradáč, Václav. "Komprese obrazu pomocí vlnkové transformace." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2017. http://www.nusl.cz/ntk/nusl-363886.

Full text
Abstract:
This work deals with image compression using wavelet transformation. At the beginning , you can find theoretical information about the best known techniques used for image compression , a thorough description of wavelet transormation and the EBCOT algorithm. A significant part of the work is devoted to the library's own implementation . Another chapter of the diploma thesis deals with the comparison and evaluation of the achieved results of the processed library with the JPEG2000 format
APA, Harvard, Vancouver, ISO, and other styles
5

Saravi, Sara. "Use of Coherent Point Drift in computer vision applications." Thesis, Loughborough University, 2013. https://dspace.lboro.ac.uk/2134/12548.

Full text
Abstract:
This thesis presents the novel use of Coherent Point Drift in improving the robustness of a number of computer vision applications. CPD approach includes two methods for registering two images - rigid and non-rigid point set approaches which are based on the transformation model used. The key characteristic of a rigid transformation is that the distance between points is preserved, which means it can be used in the presence of translation, rotation, and scaling. Non-rigid transformations - or affine transforms - provide the opportunity of registering under non-uniform scaling and skew. The idea is to move one point set coherently to align with the second point set. The CPD method finds both the non-rigid transformation and the correspondence distance between two point sets at the same time without having to use a-priori declaration of the transformation model used. The first part of this thesis is focused on speaker identification in video conferencing. A real-time, audio-coupled video based approach is presented, which focuses more on the video analysis side, rather than the audio analysis that is known to be prone to errors. CPD is effectively utilised for lip movement detection and a temporal face detection approach is used to minimise false positives if face detection algorithm fails to perform. The second part of the thesis is focused on multi-exposure and multi-focus image fusion with compensation for camera shake. Scale Invariant Feature Transforms (SIFT) are first used to detect keypoints in images being fused. Subsequently this point set is reduced to remove outliers, using RANSAC (RANdom Sample Consensus) and finally the point sets are registered using CPD with non-rigid transformations. The registered images are then fused with a Contourlet based image fusion algorithm that makes use of a novel alpha blending and filtering technique to minimise artefacts. The thesis evaluates the performance of the algorithm in comparison to a number of state-of-the-art approaches, including the key commercial products available in the market at present, showing significantly improved subjective quality in the fused images. The final part of the thesis presents a novel approach to Vehicle Make & Model Recognition in CCTV video footage. CPD is used to effectively remove skew of vehicles detected as CCTV cameras are not specifically configured for the VMMR task and may capture vehicles at different approaching angles. A LESH (Local Energy Shape Histogram) feature based approach is used for vehicle make and model recognition with the novelty that temporal processing is used to improve reliability. A number of further algorithms are used to maximise the reliability of the final outcome. Experimental results are provided to prove that the proposed system demonstrates an accuracy in excess of 95% when tested on real CCTV footage with no prior camera calibration.
APA, Harvard, Vancouver, ISO, and other styles
6

Tournadour, Elsa. "Architecture et dynamique sédimentaire d'une pente carbonatée moderne : exemple de la pente nord de Little Bahama Bank (LBB), Bahamas." Thesis, Bordeaux, 2015. http://www.theses.fr/2015BORD0201/document.

Full text
Abstract:
Cette étude présente les architectures et la dynamique sédimentaire de la pente carbonatée au nord de Little Bahama Bank (Bahamas) à partir des données de sondeur multifaisceaux, de sondeur de sédiments (Chirp) et de sismique multitraces Haute Résolution (HR) issues de la mission Carambar 1(2010). Une analyse morpho-sédimentaire de surface permet de définir les grands domaines physiographiques et les éléments architecturaux de la pente et précise la répartition spatiale des sédiments dans le contexte actuel de haut niveau marin relatif. Elle révèle une pente dominée par de la boue de périplate-forme avec différents niveaux d’induration et entaillée par des glissements et des canyons sous marins.La variabilité spatiale du transfert de boue depuis la plate-forme vers la pente, couplée à l’évolution latérale de l’intensité du courant des Antilles est à l’origine de grandes différences morphologiques d’est en ouest. Dans la partie occidentale, la pente est environ deux fois plus étendue que dans la partie orientale,elle s’apparente à un système progradant. La pente orientale, quant à elle, est marquée par des processus de bypass. En effet, cette partie est caractérisée par de nombreux canyons sous-marins se poursuivant par des sillons distributaires alimentant des zones de dépôts distales confinées. Une étude intégrée permet la caractérisation à haute résolution des glissements et des canyons et la proposition d’un modèle déformation. Ces éléments architecturaux sont initiés par des déstabilisations intra-pente et leur évolution est contrôlée par des épisodes d’érosion régressive, la sédimentation pélagique et les écoulements gravitaires boueux. Enfin, une analyse sismo-stratigraphique permet de reconstituer l’évolution tectono-sédimentaire de la pente de l’Albien à l’Actuel en lien avec le contexte géodynamique des Caraïbes, l’eustatisme et la production carbonatée sur la plate-forme
This study focuses on the architectures and the sedimentary dynamic of a carbonate slope located on the northern part of Little Bahama Bank (Bahamas) using a dataset composed of multibeam echo sounder,subbottom profiler (Chirp) and High-Resolution (HR) multichannel seismic collected during the Carambar 1cruise (2010). A morpho-sedimentary surface analysis defines the physiographic domains and the architectural elements of the slope and investigates the spatial distribution of sediments in the context of the current sea-level highstand. It reveals a slope dominated by periplatform ooze with several levels of induration and incised by numerous slides and submarine canyons. The spatial variability of off-bank transport, combined with the lateral variability of the Antilles Current intensity, are at the origin of a morphological evolution from west to east in the study area. In the western part, the slope is around twice as large as the eastern part and can be considered as a prograding system. The eastern slope is marked by bypass processes. Indeed, numerous submarine canyons are visible on the seafloor and are connected to several shallow distributary furrows feeding confined depositional areas. An integrated study allows a high resolution characterisation of slides and submarines canyons and enables us to propose a model of formation. These architectural elements are initiated by intra-slope destabilisations and their evolution is controlled by phases of retrogressive erosion,pelagic sedimentation and muddy gravity flows. Finally, a seismo-stratigraphic analysis allow to reconstitutethe tectonic and sedimentary evolution of the slope since the Albian to the present-day by establishing a link with the geodynamic context of Caraïbes, relative sea-level changes and the carbonate production on the platform
APA, Harvard, Vancouver, ISO, and other styles
7

Grossir, Guillaume. "Longshot hypersonic wind tunnel flow characterization and boundary layer stability investigations." Doctoral thesis, Universite Libre de Bruxelles, 2015. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209044.

Full text
Abstract:
The hypersonic laminar to turbulent transition problem above Mach 10 is addressed experimentally in the short duration VKI Longshot gun tunnel. Reentry conditions are partially duplicated in terms of Mach and Reynolds numbers. Pure nitrogen is used as a test gas with flow enthalpies sufficiently low to avoid its dissociation, thus approaching a perfect gas behavior. The stabilizing effects of Mach number and nosetip bluntness on the development of natural boundary layer disturbances are evaluated over a 7 degrees half-angle conical geometry without angle of attack.

Emphasis is initially placed on the flow characterization of the Longshot wind tunnel where these experiments are performed. Free-stream static pressure diagnostics are implemented in order to complete existing stagnation point pressure and heat flux measurements on a hemispherical probe. An alternative method used to determine accurate free-stream flow conditions is then derived following a rigorous theoretical approach coupled to the VKI Mutation thermo-chemical library. Resulting sensitivities of free-stream quantities to the experimental inputs are determined and the corresponding uncertainties are quantified and discussed. The benefits of this different approach are underlined, revealing the severe weaknesses of traditional methods based on the measurement of reservoir conditions and the following assumptions of an isentropic and adiabatic flow through the nozzle. The operational map of the Longshot wind tunnel is redefined accordingly. The practical limits associated with the onset of nitrogen flow condensation under non-equilibrium conditions are also accounted for.

Boundary layer transition experiments are then performed in this environment with free-stream Mach numbers ranging between 10-12. Instrumentation along the 800mm long conical model includes flush-mounted thermocouples and fast-response pressure sensors. Transition locations on sharp cones compare favorably with engineering correlations. A strong stabilizing effect of nosetip bluntness is reported and no transition reversal regime is observed for Re_RN<120000. Wavelet analysis of wall pressure traces denote the presence of inviscid instabilities belonging to Mack's second mode. An excellent agreement with Linear Stability Theory results is obtained from which the N-factor of the Longshot wind tunnel in these conditions is inferred. A novel Schlieren technique using a short duration laser light source is developed, allowing for high-quality flow visualization of the boundary layer disturbances. Comparisons of these measurement techniques between each other are finally reported, providing a detailed view of the transition process above Mach 10.
Doctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished

APA, Harvard, Vancouver, ISO, and other styles
8

Ibrahim, Soad. "Remote Sensing Region Based Image Fusion Using the Contourlet Transform." Thesis, 2012. http://hdl.handle.net/10214/3294.

Full text
Abstract:
Remote sensing imaging is a tool for collecting information about the Earth's surface such as soil, vegetation and water. Recent progress in electronics, telecommunications and sensor developments have resulted in the launch of many satellites in the past three decades. Different sensors in remote sensing systems capture a variety of images with differing characteristics. Image fusion has been used to integrate two or more images and provides output images with better accuracy. This research provides a new technique for image fusion using the contourlet transform in combination with the YCbCr color space. The output images preserve both the spectral and spatial characteristics of the input images and they are better for human and machine interpretation. This technique provides solutions to some problems (\emph{i.e.}, ghosting effect, and blocking artifacts) which the traditional image fusion techniques fail to address. The proposed technique is tested on both classical and remote sensing images. Quality metrics are used to evaluate the results of the proposed technique. The results proved significant enhancement of the quality of the output images. More fine details are successfully captured and the original chromaticity information is preserved as well. The proposed technique eliminates the blocking artifacts in the output images. Also, a new metric is presented to measure the blocking artifacts in the fused image. The results showed that increasing the number of contourlet decomposition levels does not degrade the quality of the output image. Therefore, the output images do not lose their chromaticity information when the number of contourlet decomposition levels increases. The proposed technique is tested on a variety of the remote sensing images that have large resolution ratios (\emph{i.e.}, 1:8, 1:16 and 1:32). The proposed technique is robust and suitable for many image applications. The detection of the concealed objects is an example of such applications, where the proposed technique is tested to measure its capability to fuse images with different features. The results of the Contourlet-YCbCr fusion technique are compared with the conventional fusion methods, where the proposed technique is more capable in detecting the hidden objects and preserving the original color components of the input image.
APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "Contourlet transform"

1

Natarajan, V., and R. Anitha. "Universal Steganalysis Using Contourlet Transform." In Advances in Intelligent Systems and Computing, 727–35. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-30111-7_69.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Chandra, P. Sharath, M. C. Hanumantharaju, and M. T. Gopalakrishna. "Retinal Based Image Enhancement Using Contourlet Transform." In Advances in Intelligent Systems and Computing, 581–87. Cham: Springer International Publishing, 2015. http://dx.doi.org/10.1007/978-3-319-12012-6_64.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Mansoor, Atif Bin, M. Mumtaz, H. Masood, M. Asif A. Butt, and Shoab A. Khan. "Personal Identification Using Palmprint and Contourlet Transform." In Advances in Visual Computing, 521–30. Berlin, Heidelberg: Springer Berlin Heidelberg, 2008. http://dx.doi.org/10.1007/978-3-540-89646-3_51.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Khare, Ashish, Richa Srivastava, and Rajiv Singh. "Edge Preserving Image Fusion Based on Contourlet Transform." In Lecture Notes in Computer Science, 93–102. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-31254-0_11.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Xu, Liang, Junping Du, Qingping Li, and JangMyung Lee. "Saliency Preserved Image Fusion Using Nonsubsampled Contourlet Transform." In Lecture Notes in Electrical Engineering, 349–57. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-38466-0_39.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Zaveri, Tanish, and Mukesh Zaveri. "A Novel Hybrid Pansharpening Method Using Contourlet Transform." In Lecture Notes in Computer Science, 363–68. Berlin, Heidelberg: Springer Berlin Heidelberg, 2009. http://dx.doi.org/10.1007/978-3-642-11164-8_59.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Amro, Israa, and Javier Mateos. "Multispectral Image Pansharpening Based on the Contourlet Transform." In Information Optics and Photonics, 247–61. New York, NY: Springer New York, 2010. http://dx.doi.org/10.1007/978-1-4419-7380-1_20.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Javidan, Reza. "Seabed Image Texture Analysis Using Subsampled Contourlet Transform." In Communications in Computer and Information Science, 337–48. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-22729-5_29.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Godzwon, Monika, and Khalid Saeed. "Biometrics Image Denoising Algorithm Based on Contourlet Transform." In Computer Vision and Graphics, 735–42. Berlin, Heidelberg: Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-642-33564-8_88.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Hu, Ying, Biao Hou, Shuang Wang, and Licheng Jiao. "Texture Classification Via Stationary-Wavelet Based Contourlet Transform." In Advances in Machine Vision, Image Processing, and Pattern Analysis, 485–94. Berlin, Heidelberg: Springer Berlin Heidelberg, 2006. http://dx.doi.org/10.1007/11821045_51.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Contourlet transform"

1

Hui Zeng, Zhi-Chung Mu, and Li Yuan. "Contourlet transform based EAR recognition." In 2009 International Conference on Wavelet Analysis and Pattern Recognition (ICWAPR). IEEE, 2009. http://dx.doi.org/10.1109/icwapr.2009.5207421.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Sivakumar, R., G. Balaji, R. S. J. Ravikiran, R. Karikalan, and S. Saraswathi Janaki. "Image Denoising using Contourlet Transform." In 2009 Second International Conference on Computer and Electrical Engineering. IEEE, 2009. http://dx.doi.org/10.1109/iccee.2009.70.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Butt, M. Asif Afzal, Hassan Masood, Mustafa Mumtaz, Atif Bin Mansoor, and Shoab A. Khan. "Palmprint Identification Using Contourlet Transform." In 2008 IEEE Second International Conference on Biometrics: Theory, Applications and Systems. IEEE, 2008. http://dx.doi.org/10.1109/btas.2008.4699342.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Abdulhameed Al-Rawi, Zainab N., Haraa R. Hatem, and Israa H. Ali. "Image Compression Using Contourlet Transform." In 2018 1st Annual International Conference on Information and Sciences (AiCIS). IEEE, 2018. http://dx.doi.org/10.1109/aicis.2018.00053.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Zewail, Rami, Mrinal Mandal, and Nelson Durdle. "Iris identification using contourlet transform." In Electronic Imaging 2007, edited by Jaakko T. Astola, Karen O. Egiazarian, and Edward R. Dougherty. SPIE, 2007. http://dx.doi.org/10.1117/12.703511.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Gao, Guangyong, Baoqin Cai, Shaowen Xu, and Tao Yan. "Watermark performance contrast between contourlet and non-subsampled contourlet transform." In 2012 International Conference on Information and Automation (ICIA). IEEE, 2012. http://dx.doi.org/10.1109/icinfa.2012.6246859.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Ning, Jianglan, Dan Wu, Bing Han, and Wenyi Ren. "Image enhancement based on Contourlet transform." In The International Conference on Photonics and Optical Engineering, edited by Ailing Tian. SPIE, 2019. http://dx.doi.org/10.1117/12.2522004.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Shah, Vijay P., Nicolas H. Younan, and Roger King. "Pan-sharpening via the contourlet transform." In 2007 IEEE International Geoscience and Remote Sensing Symposium. IEEE, 2007. http://dx.doi.org/10.1109/igarss.2007.4422792.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Mosleh, Ali, Farzad Zargari, and Reza Azizi. "Texture image retrieval using contourlet transform." In 2009 International Symposium on Signals, Circuits and Systems - ISSCS 2009. IEEE, 2009. http://dx.doi.org/10.1109/isscs.2009.5206182.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Zhiling Long, Qian Du, and Nicolas H. Younan. "Hyperspectral feature extraction using contourlet transform." In 2012 7th IAPR Workshop on Pattern Recognition in Remote Sensing (PRRS). IEEE, 2012. http://dx.doi.org/10.1109/pprs.2012.6398317.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Contourlet transform' for particular source types:
Journal articles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography