The Experts below are selected from a list of 17850 Experts worldwide ranked by ideXlab platform
Eisaku Kanazawa - One of the best experts on this subject based on the ideXlab platform.
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sexual dimorphism in the japanese cranial base a fourier Wavelet Representation
American Journal of Physical Anthropology, 2005Co-Authors: Pete E Lestrel, Roberto M Cesar, Osamu Takahashi, Eisaku KanazawaAbstract:An approach, computational shape analysis (CSA), is presented here which utilizes a Fourier-Wavelet Representation to numerically describe shape features of biological forms. Two elements are involved: 1) elliptical Fourier functions (EFFs), to provide estimates of global aspects, and 2) continuous Wavelet transforms (CWTs) to generate an objective estimate of localized features. EFFs are computed, using a set of pseudohomologous points, to create a precise analog of the boundary. This computed contour is then normalized by scaling and rotated in two-dimensional space to insure a Representation that is invariant with respect to starting point, size, and orientation. The predicted point coordinates derived from the EFFs are submitted to CWT for further processing. Wavelet coefficients are then computed to identify localized features, localization being a subjective process with EFFs. The advantage of Wavelets is that they eliminate the inevitable subjectivity inherent in the choice of measurements. To test the usefulness of CSA, a sample of cranial base (CB) lateral radiographic outlines was available. Five archaeological periods, Yayoi, Kofun, Kamakura, Edo, and Modern, were utilized (n = 297). Statistically significant differences in sex and archaeological age were found. Although archaeological age differences were present, they were small and random in character, suggesting stability in the CB structures. In contrast, sexually dimorphic differences were present in every group from the Yayoi to the Modern period. This presence of sexually dimorphic differences in shape was consistent with earlier studies of M. nemestrina, G. gorilla, and P. troglodytes. Consequently, it is suggested that the pattern of sexual dimorphism documented in the Japanese CB is a primate pattern with an ancient evolutionary history. The results demonstrate, both visually and numerically, that CSA is a powerful approach for describing both global and localized features of craniofacial structures such as the CB. Am J Phys Anthropol, 2005. © 2005 Wiley-Liss, Inc.
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Sexual dimorphism in the Japanese cranial base: a Fourier-Wavelet Representation.
American journal of physical anthropology, 2005Co-Authors: Pete E Lestrel, Roberto M Cesar, Osamu Takahashi, Eisaku KanazawaAbstract:An approach, computational shape analysis (CSA), is presented here which utilizes a Fourier-Wavelet Representation to numerically describe shape features of biological forms. Two elements are involved: 1) elliptical Fourier functions (EFFs), to provide estimates of global aspects, and 2) continuous Wavelet transforms (CWTs) to generate an objective estimate of localized features. EFFs are computed, using a set of pseudohomologous points, to create a precise analog of the boundary. This computed contour is then normalized by scaling and rotated in two-dimensional space to insure a Representation that is invariant with respect to starting point, size, and orientation. The predicted point coordinates derived from the EFFs are submitted to CWT for further processing. Wavelet coefficients are then computed to identify localized features, localization being a subjective process with EFFs. The advantage of Wavelets is that they eliminate the inevitable subjectivity inherent in the choice of measurements. To test the usefulness of CSA, a sample of cranial base (CB) lateral radiographic outlines was available. Five archaeological periods, Yayoi, Kofun, Kamakura, Edo, and Modern, were utilized (n = 297). Statistically significant differences in sex and archaeological age were found. Although archaeological age differences were present, they were small and random in character, suggesting stability in the CB structures. In contrast, sexually dimorphic differences were present in every group from the Yayoi to the Modern period. This presence of sexually dimorphic differences in shape was consistent with earlier studies of M. nemestrina, G. gorilla, and P. troglodytes. Consequently, it is suggested that the pattern of sexual dimorphism documented in the Japanese CB is a primate pattern with an ancient evolutionary history. The results demonstrate, both visually and numerically, that CSA is a powerful approach for describing both global and localized features of craniofacial structures such as the CB.
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a fourier Wavelet Representation of 2 d shapes sexual dimorphism in the japanese cranial base
Anthropological Science, 2004Co-Authors: Pete E Lestrel, Roberto M Cesar, Osamu Takahashi, Eisaku KanazawaAbstract:We present a new approach called computational shape analysis, which utilizes a Fourier-Wavelet Representation for characterizing shape features of 2-D forms commonly encountered in a wide set of sub-disciplines within the biological sciences. The morphology of interest consists of the human cranial base (CB) as depicted on lateral cephalometric radiographs. Given a complex irregularly bounded form in Cartesian coordinate space, we first compute elliptical Fourier functions (EFFs) using a set of closely-spaced pseudo-homologous (x, y) points, starting at basion, to create a precise analog of the closed contour. This computed contour is then scaled (size-standardization) and rotated (positional-orientation) to provide for a common normalization. This insures that the Representation is invariant with respect to starting point, size and orientation. Utilizing the EFFs, global aspects of the CB can then be extracted. The coordinates derived from the EFF were subsequently submitted to a continuous Wavelet transform (CWT). Wavelet coefficients were then computed to identify localized features. The significant advantage of Wavelets is that they are able to objectively identify changes in boundary curvature, thereby depicting localized aspects not easily attainable with other methods. Utilizing a sample of 297 Japanese cranial base outlines, statistically-significant differences in sex and archeological age were found. Although archeological age differences were present, they were small and largely random in character, suggesting stability in the CB structures. The presence of sexually dimorphic differences is consistent with earlier data derived from studies of Macaca nemestrina. In the current study, these differences in sexual dimorphism were present for every group starting with the Yayoi period and continuing up to the Modern period. Consequently, one may infer that the pattern of sexual dimorphism documented in the Japanese CB, is a primate pattern with an ancient evolutionary history. Wavelets were particularly useful in objectively identifying this sexual dimorphism. The results demonstrate that the Fourier-Wavelet Representation is a practical approach for numerically describing and visually depicting both global and localized features.
Xavier Clady - One of the best experts on this subject based on the ideXlab platform.
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DAGM-Symposium - Real-Time Tracking Using Wavelet Representation
Lecture Notes in Computer Science, 2002Co-Authors: Thierry Chateau, Frédéric Jurie, Michel Dhome, Xavier CladyAbstract:We have recently developed an original tracking framework allowing to track textured templates in real time [3]. This framework is based on the use of difference images, the difference between the target template and the template included in predicted area of interest. For efficiency purposes, the difference image was limited to a few points belonging to the area of interest. The measurements were therefore very punctual. In this article a Wavelet Representation of the area of interest is used as a substitute for this punctual measurement. In this case, the difference image is a difference of Wavelet parameters (difference between the Wavelet Representation of the target and the Wavelet Representation of the template included in the current position of the region of interest). This algorithm is a part of a real-time system aiming at automatically detecting and tracking vehicles in video sequences.
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Real-time Tracking using Wavelet Representation
2002Co-Authors: Thierry Chateau, Frédéric Jurie, Michel Dhome, Xavier CladyAbstract:We have recently developed an original tracking framework allowing to track textured templates in real time [3]. This framework is based on the use of difference images, the difference between the target template and the template included in predicted area of interest. For efficiency purposes, the difference image was limited to a few points belonging to the area of interest. The measurements were therefore very punctual. In this article a Wavelet Representation of the area of interest is used as a substitute for this punctual measurement. In this case, the difference image is a difference of Wavelet parameters (difference between the Wavelet Representation of the target and the Wavelet Representation of the template included in the current position of the region of interest). This algorithm is a part of a real-time system aiming at automatically detecting and tracking vehicles in video sequences.
Christian Brousseau - One of the best experts on this subject based on the ideXlab platform.
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Estimation of efficiency of a tree structured hierarchical Wavelet Representation of synthetic database applied to non-cooperative target recognition
International Journal of Microwave and Wireless Technologies, 2011Co-Authors: Christian BrousseauAbstract:In this paper, problem of efficient Representation of large database of target radar cross section is investigated in order to minimize memory requirements and recognition search time, using a tree structured hierarchical Wavelet Representation. Synthetic RCS of large aircrafts, in the HF-VHF bands, are used as experimental data. Hierarchical trees are built using Wavelet multiresolution Representation and K-means clustering algorithm. Criteria used to define these hierarchical trees are described and the obtained performances are presented.
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Estimation of efficiency of a tree structured hierarchical Wavelet Representation of synthetic database applied to non-cooperative target recognition
International Journal of Microwave and Wireless Technologies, 2011Co-Authors: Christian BrousseauAbstract:In this paper, problem of efficient Representation of large database of target radar cross section (RCS) is investigated in order to minimize memory requirements and recognition search time, using a tree structured hierarchical Wavelet Representation. Synthetic RCS of large aircrafts, in the High Frequency (HF)–Very High Frequency (VHF) bands, are used as experimental data. Hierarchical trees are built using Wavelet multiresolution Representation and K-means clustering algorithm. Criteria used to define these hierarchical trees are described and the obtained performances are presented.
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Development of a tree structured hierarchical Wavelet Representation of synthetic database to NCTR
2010 IEEE Radar Conference, 2010Co-Authors: Christian BrousseauAbstract:In this paper, problem of efficient Representation of large database of target radar cross section is investigated in order to minimize memory requirements and recognition search time, using a tree structured hierarchical Wavelet Representation. Synthetic RCS of large aircrafts, in the HF-VHF bands, are used as experimental data. Hierarchical trees are built using Wavelet multiresolution Representation and K-means clustering algorithm. Criteria used to define these hierarchical trees are described and the obtained performances are presented.
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Application of the multiresolution Wavelet Representation to non-cooperative target recognition
2009Co-Authors: Christian BrousseauAbstract:In this paper, the problem of efficient Representation of large database of target radar cross section is investigated in order to minimize memory requirements and recognition search time, using Wavelet Representation. Synthetic RCS of large aircrafts, in the HF-VHF frequency bands, are used as experimental data. Many parameters are evaluated like mother Wavelet, decomposition level, and classification parameters. Criteria used to determine the efficiency of multiresolution Representations are compression scores, false identification rate and search time.
Volker Krüger - One of the best experts on this subject based on the ideXlab platform.
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DAGM-Symposium - Wavelet Subspace Method for Real-Time Face Tracking
Lecture Notes in Computer Science, 2001Co-Authors: Volker Krüger, Rogerio FerisAbstract:In this article we present a new method for visual face tracking that is carried out in Wavelet subspace. Firstly, a Wavelet Representation for the face template is created, which spans a low dimensional subspace of the image space. The Wavelet Representation of the face is a point in this Wavelet subspace. The video sequence frames in which the face is tracked are orthogonally projected into this low-dimensional subspace. This can be done efficiently through a small number of local projections of the Wavelet functions. All further computations are then performed in the low-dimensional subspace. The Wavelet subspace inherets its invariance to rotation, scale and translation from the Wavelets; shear invariance can also be achieved, which makes the subspace invariant to affine deformations.
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affine real time face tracking using gabor Wavelet networks
International Conference on Pattern Recognition, 2000Co-Authors: Volker Krüger, A. Happe, Gerald SommerAbstract:We present a method for visual face tracking that is based on a Wavelet Representation of a face template. The Wavelet Representation allows: arbitrary affine deformations of the facial image; generalization from an individual face template to a rather general face template; and adapting the computational needs of the tracking algorithm to the computational resources available. The method presented was implemented on a Linux Pentium 450 MHz and runs off-line with 25 Hz, and online using an active camera mount at 22 Hz. We present experimental results on the off-line tests on several common image sequences including the salesman-sequence as well as on the online tests.
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Affine real-time face tracking using a Wavelet network
Proceedings International Workshop on Recognition Analysis and Tracking of Faces and Gestures in Real-Time Systems. In Conjunction with ICCV'99 (Cat. , 1Co-Authors: Volker Krüger, A. Happe, Gerald SommerAbstract:We present a method for visual face tracking that is based on a Wavelet Representation of a face template. The Wavelet Representation allows arbitrary affine variations of the facial image, it allows to generalize from an individual face template to a rather general face template and it allows to adapt the computational needs of the tracking algorithm to the computational resources available. The method presented runs in real-time (25 Hz) on a Linux Pentium 450 MHz and was tested on several common sequences including the salesman-sequence.
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ICPR - Affine real-time face tracking using Gabor Wavelet networks
Proceedings 15th International Conference on Pattern Recognition. ICPR-2000, 1Co-Authors: Volker Krüger, A. Happe, Gerald SommerAbstract:We present a method for visual face tracking that is based on a Wavelet Representation of a face template. The Wavelet Representation allows: arbitrary affine deformations of the facial image; generalization from an individual face template to a rather general face template; and adapting the computational needs of the tracking algorithm to the computational resources available. The method presented was implemented on a Linux Pentium 450 MHz and runs off-line with 25 Hz, and online using an active camera mount at 22 Hz. We present experimental results on the off-line tests on several common image sequences including the salesman-sequence as well as on the online tests.
W Strasser - One of the best experts on this subject based on the ideXlab platform.
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interactive rendering of large volume data sets
IEEE Visualization, 2002Co-Authors: Stefan Guthe, Michael Wand, J Gonser, W StrasserAbstract:We present a new algorithm for rendering very large volume data sets at interactive frame rates on standard PC hardware. The algorithm accepts scalar data sampled on a regular grid as input. The input data is converted into a compressed hierarchical Wavelet Representation in a preprocessing step. During rendering, the Wavelet Representation is decompressed on-the-fly and rendered using hardware texture mapping. The level of detail used for rendering is adapted to the local frequency spectrum of the data and its position relative to the viewer. Using a prototype implementation of the algorithm we were able to perform an interactive walkthrough of large data sets such as the visible human on a single off-the-shelf PC.
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IEEE Visualization - Interactive rendering of large volume data sets
2002Co-Authors: Stefan Guthe, Michael Wand, J Gonser, W StrasserAbstract:We present a new algorithm for rendering very large volume data sets at interactive framerates on standard PC hardware. The algorithm accepts scalar data sampled on a regular grid as input. The input data is converted into a compressed hierarchical Wavelet Representation in a preprocessing step. During rendering, the Wavelet Representation is decompressed on-the-fly and rendered using hardware texture mapping. The level of detail used for rendering is adapted to the local frequency spectrum of the data and its position relative to the viewer. Using a prototype implementation of the algorithm we were able to perform an interactive walkthrough of large data sets such as the visible human on a single of-the-shelf PC.
