Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 27
Primeira ... 12 ... Última
Imagem não selecionada

Imprime registro no formato completo
A Learning Approach for Adaptive Image Segmentation InTech
Vincent Martin; Monique Thonnat.
In this chapter, we have proposed a learning approach for three major issues of image segmentation: context adaptation, algorithm selection and parameter tuning according to the image content and the application need. This supervised learning approach relies on hand-labelled samples. The learning process is guided by the goal of the segmentation and therefore makes the approach reliable for a broad range of applications. The user effort is restrained compared to other supervised methods since it does not require image processing skills: the user has just to click into regions to assign labels; he/she never interacts with algorithm parameters. For the figure-ground segmentation task in video application, this annotation task is even automatic. When all...
Tipo: 23 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/a_learning_approach_for_adaptive_image_segmentation
Imagem não selecionada

Imprime registro no formato completo
A Novel Omnidirectional Stereo Vision System via a Single Camera InTech
Chuanjiang Luo; Liancheng Su; Feng Zhu.
We have developed a complete framework of automatically generating omnidirectional depth maps around a mobile robot using a novel designed panoramic vision sensor. Compared to previous vision systems, our system has such significant advantages as its geometry calculating easy and fast and simultaneous acquisition of precise range information without high cost or system complexity. And as the separation between the two hyperbolic mirrors provides a large baseline, the range information obtained from this method has much improved precision. We have proposed an imaging model for
Tipo: 2 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/a_novel_omnidirectional_stereo_vision_system_via_a_single_camera
Imagem não selecionada

Imprime registro no formato completo
A Novel Omnidirectional Stereo Vision System with a Single Camera InTech
Sooyeong Yi; Narendra Ahuja.
Wide field of view is the most attractive feature of the omnidirectional vision. There exist two approaches to omnidirectional stereo imaging with a single camera. They use: (1) a double lobed mirror (Fiala & Basu, 2005)(Cabral et al., 2004), or (2) two mirrors (Jang et al., 2005). In this paper, a third approach is described using a mirror and a concave lens. By adjusting the position of the concave lens, it is possible to control the disparity between two stereo images and the accuracy of the 3D distance computation. Since the optical components adopted in the proposed system are commercially available, the proposed omnidirectional stereo imaging system is compact and cost-effective. Based on the simple optics composed of the reflection and the...
Tipo: 24 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/a_novel_omnidirectional_stereo_vision_system_with_a_single_camera
Imagem não selecionada

Imprime registro no formato completo
A Pseudo Stereo Vision Method using Asynchronous Multiple Cameras InTech
Shoichi Shimizu; Hironobu Fujiyoshi; Yasunori Nagasaka; Tomoichi Takahashi.
We proposed a method of pseudo-stereo vision method using cameras with different shutter timings, where the previous two frames were calculated using a spline curve. The method can output a 3D position at 90 fps using three cameras, and using multiple cameras is expected to enhance the output of the 3D positions. We confirmed that our method was better than stereo vision with the time delay in simulation experiments. The error was 9.2 mm in experiments using real cameras. However, the error was within a useful range, because the object’s radius was 20 mm. Moreover, it is clear that our method is better than the stereo vision with asynchronous shutter timing.
Tipo: 11 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/a_pseudo_stereo_vision_method_using_asynchronous_multiple_cameras
Imagem não selecionada

Imprime registro no formato completo
A Sensors System for Indoor Localisation of a Moving Target Based on Infrared Pattern Recognition InTech
Nikos Petrellis; Nikos Konofaos; George Alexiou.
A novel method for the indoor localisation of a target was presented in this chapter. This method is based on measuring the number of the digital infrared patterns received by the target in a specific time interval (success rate). At least two transmitting devices are placed around the covered area that exceeds 15m2, while a pair of infrared receivers are mounted on the target. This area is supposed to be covered by a virtual grid and can be further extended if more transmitters are employed. The grid nodes are visited by the target during a calibration stage when it familiarises with the retrieved success rates. At real time operation the closer grid node is selected and a refinement step based on a 2D interpolation search follows leading to a more...
Tipo: 16 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/a_sensors_system_for_indoor_localisation_of_a_moving_target_based_on_infrared_pattern_recognition
Imagem não selecionada

Imprime registro no formato completo
A Tutorial on Parametric Image Registration InTech
Leonardo Romero; Felix Calderon.
A tutorial, with all the details related to the parametric image registration task, has been presented. Also two new methods (Method 1 and Method 3) are presented besides the classical method to compute derivatives of images. Method 1 computes the image derivatives faster than the other two methods, but it does not give accurate estimations. Methods 2 and 3 take more time because they compute derivatives of the transformed image (at each iteration) while method 1 computes derivatives of the input image only once. Method 3 is an improved version of method 2 because it takes into account the exact derivatives needed. However the classical method 2, reported in the literature is the same as the method 3 under translations. Experiments confirm the poor...
Tipo: 10 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/a_tutorial_on_parametric_image_registration
Imagem não selecionada

Imprime registro no formato completo
An Introduction to Model-Based Pose Estimation and 3-D Tracking Techniques InTech
Christophe Doignon.
With this article, we have addressed some issues in pose estimation with geometrical features and a modelbased approach in the context of monocular vision. While the 3-D tracking/estimation may be performed with optimal estimators (with the Kalman filter and its extended/nonlinear versions or with the particle filter also referred to as the sequential Monte Carlo method), system models and state vectors need the pose parameters recovery or the 3-D motion recovery from the motion field. The pose determination is needed for applications with high accurate 3-D positioning requirements, when occlusions, shadows or abrupt motions have to be handle. To this purpose, several geometrical featurebased approaches have been reviewed for solving the pose with various...
Tipo: 20 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/an_introduction_to_model-based_pose_estimation_and_3-d_tracking_techniques
Imagem não selecionada

Imprime registro no formato completo
Analysis of Video-Based 3D Tracking Accuracy by Using Electromagnetic Tracker as a Reference InTech
Matjaz Divjak; Damjan Zazula.
When a magnetic tracker is used as a reference for vision-based tracking, a reliable transformation of their coordinate systems is crucial for proper tracking accuracy estimation. To address this issue in more detail, three different models of coordinate system alignment were developed. By analyzing the worst-case sensitivity of transformation models a limited comparison of those models is possible. The most influential model parameters are easy to identify and should be measured with special care. However, the actual parameter values used also have a significant effect on the final transformation error. With appropriate selection of parameter values, any model can be manipulated to produce the most accurate transformation. Therefore, such comparisons are...
Tipo: 6 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/analysis_of_video-based_3d_tracking_accuracy_by_using_electromagnetic_tracker_as_a_reference
Imagem não selecionada

Imprime registro no formato completo
Articulated Hand Tracking by ICA-based Hand Model and Multiple Cameras InTech
Makoto Kato; Gang Xu; Yen-Wei Chen.
In this chapter, we proposed three new approaches, the ICA-based hand model, articulated hand motion tracking by multiple cameras, and Particle filtering with prediction. The ICA-based hand model is the ICA-based representation of hand articulation for tracking hand-finger gestures in image sequences. The dimensionality of the hand motion space is reduced by PCA and then ICA is applied to extract the local feature vectors. In the ICAbased model, each of the first five basis vectors corresponds to a particular finger motion, because the joints in each finger have stronger dependencies than the joints across different fingers. In the ICA-based model, hand poses can be represented by five parameters with each parameter corresponding to a particular finger...
Tipo: 26 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/articulated_hand_tracking_by_ica-based_hand_model_and_multiple_cameras
Imagem não selecionada

Imprime registro no formato completo
Bimanual Hand Tracking based on AR-KLT InTech
Hye-Jin Kim; Keun-Chang Kwak; Jae Jeon Lee.
Our ARKLT method is very useful for tracking and gesture recognition. As mentioned before, the ARKLT method consists of three points for each hand: the shoulder, elbow and hand. Since the model reflects the articulated motion of the human body which is restrained by the each limb's degree of freedom. That is, the possible region for hand movement is restricted in the elongated region of the shoulder and elbow movement. Therefore, the proposed method can devise effective prediction method, which enables to pre-detect crossing hands based on the body structure. In addition, the proposed method applies the KLT features and their regression line so that the body structure can effectively be fitted into the target. Also, the well-fitted KLT line can provide the...
Tipo: 19 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/bimanual_hand_tracking_based_on_ar-klt
Imagem não selecionada

Imprime registro no formato completo
Biologically Motivated Vergence Control System Based on Stereo Saliency Map Model InTech
Sang-Woo Bana; Minho Lee.
We proposed a new biologically motivated vergence control method of an active stereo vision system that mimics human-like stereo visual selective attention. We used a trainable selective attention model that can decide an interesting area by the low-level top-down mechanism implemented by Fuzzy ART training model in conjunction with the bottom-up static SM model. In the system, we proposed a landmark selection method using the lowlevel top-down trainable selective attention model and the IOR regions. Also, a depth estimation method was applied for reflecting stereo saliency. Based on the proposed algorithm, we implemented a human-like active stereo vision system. From the computer simulation and experimental results, we showed the effectiveness of the...
Tipo: 27 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/biologically_motivated_vergence_control_system_based_on_stereo_saliency_map_model
Imagem não selecionada

Imprime registro no formato completo
Collaborative MR Workspace with Shared 3D Vision Based on Stereo Video Transmission InTech
Shengjin Wang; Yaolin Tan; Jun Zhou; Tao Wu; Wei Lin.
We have presented a framework of collaborative MR workspace with shared three dimensional vision based on stereo video transmission, established and experimented for collaborative operation. The system provide a 3D-like operating interface by a CG indicator. Though the system is tested successfully for the data transmission in both IPv4 LAN and over three layers of node point with IPv6 environment there still several tasks need to be accomplished in future work. The one is although we regard a CG indicator as 3D CG models now, for a widely use more 3D CG may need to be added into virtual space and operated in shift, rotate, and spin, as an extended function in future. The second is that
Tipo: 8 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/collaborative_mr_workspace_with_shared_3d_vision_based_on_stereo_video_transmission
Imagem não selecionada

Imprime registro no formato completo
Continuous Machine Learning in Computer Vision - Tracking with Adaptive Class Models InTech
Rustam Stolkin.
This chapter has explored a number of techniques in vision based tracking, with the common theme of continuous relearning of models of the background and the tracked
Tipo: 15 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/continuous_machine_learning_in_computer_vision_-_tracking_with_adaptive_class_models
Imagem não selecionada

Imprime registro no formato completo
Correcting Radial Distortion of Cameras with Wide Angle Lens Using Point Correspondences InTech
Leonardo Romero; Cuauhtemoc Gomez.
We propose a robust method to remove radial distortion from images using a reference image as a guide. It is based on point correspondences between the acquired image from the
Tipo: 4 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/correcting_radial_distortion_of_cameras_with_wide_angle_lens_using_point_correspondences
Imagem não selecionada

Imprime registro no formato completo
Global Techniques for Edge based Stereo Matching InTech
Yassine Ruichek; Mohamed Hariti; Hazem Issa.
We proposed global techniques for edge stereo matching. The problem is formulated as a constraint satisfaction problem where the objective is to highlight a solution for which the matches are as compatible as possible with respect to specific constraints: local constraints and global ones. The local constraints are used to discard impossible matches so as to consider only potentially acceptable pairs of edges as candidates. The global constraints are used to evaluate the compatibility between the possible matches in order to determine the best ones. In the first technique, the problem is turned into an optimization task where an objective function, representing the global constraints, is mapped and minimized thanks to a Hopfield neural network. This neural...
Tipo: 21 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/global_techniques_for_edge_based_stereo_matching
Imagem não selecionada

Imprime registro no formato completo
Image Processing Techniques for Unsupervised Pattern Classification InTech
C. Botte-Lecocq; K. Hammouche; A. Moussa; J.-G. Postaire; A. Sbihi; A. Touzani.
All the clustering methods presented in this chapter tend to generalize bi-dimensional procedures initially developed for image processing purpose. Among them, thresholding, edge detection, probabilistic relaxation, mathematical morphology, texture analysis, and Markov field models appear to be valuable tools with a wide range of applications in the field of unsupervised pattern classification. Following the same idea of adapting image processing techniques to cluster analysis, one of our other objectives is to model spatial relationships between pixels by means of other textural parameters derived from autoregressive models (Comer & Delp, 1999), Markov random fields models (Cross & Jain, 1983), Gabor filters (Jain & Farrokhnia, 1991), wavelet...
Tipo: 25 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/image_processing_techniques_for_unsupervised_pattern_classification
Imagem não selecionada

Imprime registro no formato completo
Local Feature Selection and Global Energy Optimization in Stereo InTech
Hiroshi Ishikawa; Davi Geiger.
We have presented a new approach to compute the disparity map, first by selecting optimal feature locally, so that the chosen local energy function gives the most confident selection of the disparity from each set of mutually exclusive choices, then by modelling occlusions, discontinuities, and epipolar-line interactions as a MAP optimization problem, which is
Tipo: 22 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/local_feature_selection_and_global_energy_optimization_in_stereo
Imagem não selecionada

Imprime registro no formato completo
Multiple Omnidirectional Vision System and Multilayered Fuzzy Behavior Control for Autonomous Mobile Robot InTech
Yoichiro Maeda.
The multiple omnidirectional vision system (MOVIS) with three omni-cameras and its selflocalization method for the autonomous mobile robot were proposed in this paper. Moreover, the experiment of the measurement performance and self-localization by MOVIS on the real miniature soccer field was carried out by using the proposed method. As a result, we confirmed that the measurement of MOVIS is remarkably more accurate than that of a single omni-vision and the vertical stereo omni-vision, and the self-localization performance is relatively useful in all area of soccer field. In the near future, we would like to develop the real soccer robot with MOVIS and the proposed self-localization method.
Tipo: 9 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/multiple_omnidirectional_vision_system_and_multilayered_fuzzy_behavior_control_for_autonomous_mobile
Imagem não selecionada

Imprime registro no formato completo
Non-rigid Stereo-motion InTech
Alessio Del Bue; Lourdes Agapito.
The authors would like to thank the Royal Society European Science Exchange Programme, EPSRC Grant GR/S61539/01 and the Spanish Ministry of Science project TIC2002-00591 for financial support. Enrique Mu?oz, Jose Miguel Buenaposada and Luis Baumela provided the code for the synthetic 3D face model. Thanks to Andrew Fitzgibbon for matlab functions for bundle adjustment. Alessio Del Bue is supported by Funda??o para a Ci?ncia e a Tecnologia (ISR/IST plurianual funding) through the POS_Conhecimento Program that includes FEDER funds.
Tipo: 14 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/non-rigid_stereo-motion
Imagem não selecionada

Imprime registro no formato completo
Photorealistic 3D Model Reconstruction based on the Consistency of Object Surface Reflectance Measured by the Voxel Mask InTech
K. K. Chiang; K. L. Chan; H. Y. Ip.
SFSPC works well to model objects with more color inhomogeneity or sufficient texture information. It can quite accurately carve the concave regions. However, if the object contains a large, flat area in homogeneous color, partial surface estimation may not truly identify the real surface voxels. Besides, the computational time is still a problem. The higher the resolution is set, the more accurate and finer reconstructed model is generated. However, as the number of voxels in the volumetric model increases, more computation is needed to process the entire model. As for SFSPC, most of the time is spent on the partial surface estimation process. The computational time is directly proportional to the number of remaining voxels after the voting-based SFS. It...
Tipo: 7 Palavras-chave: Scene Reconstruction Pose Estimation and Tracking.
Ano: 2007 URL: http://www.intechopen.com/articles/show/title/photorealistic_3d_model_reconstruction_based_on_the_consistency_of_object_surface_reflectance_measur
Registros recuperados: 27
Primeira ... 12 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional