The Experts below are selected from a list of 162 Experts worldwide ranked by ideXlab platform
Yungchang Chen - One of the best experts on this subject based on the ideXlab platform.
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facial Model adaptation from a monocular image sequence using a textured Polygonal Model
Signal Processing-image Communication, 2002Co-Authors: Yaojen Chang, Yungchang ChenAbstract:Although several algorithms have been proposed for facial Model adaptation from image sequences, the insufficient feature set to adapt a full facial Model, imperfect matching of feature points, and imprecise head motion estimation may degrade the accuracy of Model adaptation. In this paper, we propose to resolve these difficulties by integrating facial Model adaptation, texture mapping, and head pose estimation as cooperative and complementary processes. By using an analysis-by-synthesis approach, salient facial feature points and head profiles are reliably tracked and extracted to form a growing and more complete feature set for Model adaptation. A more robust head motion estimation is achieved with the assistance of the textured facial Model. The proposed scheme is performed with image sequences acquired with single uncalibrated camera and requires only little manual adjustment in the initialization setup, which proves to be a feasible approach for facial Model adaptation.
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robust head pose estimation using textured Polygonal Model with local correlation measure
Pacific Rim Conference on Multimedia, 2001Co-Authors: Yaojen Chang, Yungchang ChenAbstract:In this paper, a robust head pose estimation algorithm is presented. In contrast with other approaches, the proposed algorithm adopts textured Polygonal Model generated from two orthogonal views for accurate head pose estimation. To achieve robust estimation under varying illumination, local correlation coefficient is taken as the similarity measure. The tracking is further improved by Modeling head dynamics with Kalman filtering. Preliminary simulation results indicate that the proposed algorithm can reliably estimate the head pose under large rotation angles with varying illumination, and the average estimation error are all below 4 degrees.
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textured Polygonal Model assisted facial Model estimation from image sequence
International Conference on Image Processing, 2001Co-Authors: Yaojen Chang, Yungchang ChenAbstract:A 3D textured Polygonal facial Model estimation algorithm is presented. The algorithm takes facial Model estimation, texture mapping, and head pose estimation as complementary processes, which cooperate to adapt the facial Model from a generic facial Model to a user-accustomed one through image sequences. The proposed scheme is performed with a single camera without calibration and requires only a little manual adjustment, which proves to be a feasible approach for facial Model estimation.
Yaojen Chang - One of the best experts on this subject based on the ideXlab platform.
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facial Model adaptation from a monocular image sequence using a textured Polygonal Model
Signal Processing-image Communication, 2002Co-Authors: Yaojen Chang, Yungchang ChenAbstract:Although several algorithms have been proposed for facial Model adaptation from image sequences, the insufficient feature set to adapt a full facial Model, imperfect matching of feature points, and imprecise head motion estimation may degrade the accuracy of Model adaptation. In this paper, we propose to resolve these difficulties by integrating facial Model adaptation, texture mapping, and head pose estimation as cooperative and complementary processes. By using an analysis-by-synthesis approach, salient facial feature points and head profiles are reliably tracked and extracted to form a growing and more complete feature set for Model adaptation. A more robust head motion estimation is achieved with the assistance of the textured facial Model. The proposed scheme is performed with image sequences acquired with single uncalibrated camera and requires only little manual adjustment in the initialization setup, which proves to be a feasible approach for facial Model adaptation.
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robust head pose estimation using textured Polygonal Model with local correlation measure
Pacific Rim Conference on Multimedia, 2001Co-Authors: Yaojen Chang, Yungchang ChenAbstract:In this paper, a robust head pose estimation algorithm is presented. In contrast with other approaches, the proposed algorithm adopts textured Polygonal Model generated from two orthogonal views for accurate head pose estimation. To achieve robust estimation under varying illumination, local correlation coefficient is taken as the similarity measure. The tracking is further improved by Modeling head dynamics with Kalman filtering. Preliminary simulation results indicate that the proposed algorithm can reliably estimate the head pose under large rotation angles with varying illumination, and the average estimation error are all below 4 degrees.
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textured Polygonal Model assisted facial Model estimation from image sequence
International Conference on Image Processing, 2001Co-Authors: Yaojen Chang, Yungchang ChenAbstract:A 3D textured Polygonal facial Model estimation algorithm is presented. The algorithm takes facial Model estimation, texture mapping, and head pose estimation as complementary processes, which cooperate to adapt the facial Model from a generic facial Model to a user-accustomed one through image sequences. The proposed scheme is performed with a single camera without calibration and requires only a little manual adjustment, which proves to be a feasible approach for facial Model estimation.
Xin Chen - One of the best experts on this subject based on the ideXlab platform.
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Polygonal Model based cutter location data generation with offset error compensation
Rapid Prototyping Journal, 2016Co-Authors: Hao Wen, Jian Gao, Xin ChenAbstract:Purpose As manufacturing technology has developed, digital Models from advanced measuring devices have been widely used in manufacturing sectors. To speed up the production cycle and reduce extra errors introduced in surface reconstruction processes, directly machining digital Models in the Polygonal stereolithographyformat has been considered as an effective approach in rapid digital manufacturing. In machining processes, Cutter Location (CL) data for numerical control (NC) machining is generated usually from an offset Model. This Model is created by offsetting each vertex of the original Model along its vertex vector. However, this method has the drawback of overcut to the offset Model. The purpose of this paper is to solve the overcut problem through an error compensation algorithm to the vertex offset Model. Design/methodology/approach Based on the analysis of the vertex offset method and the offset Model generated, the authors developed and implemented an error compensation method to correct the offset Models and generated the accurate CL data for the subsequent machining process. This error compensation method is verified through three Polygonal Models and the tool paths generated were used for a real part machining. Findings Based on the analysis of the vertex offset method and the offset Model generated, the authors developed an error compensation method to correct the offset Models and generated the accurate CL data for the subsequent machining process. The developed error compensation algorithm can effectively solve the overcut drawback of the vertex offset method. Research limitations/implications The error compensation method to the vertex offset Model is used for generating the CL data with the using of a ball-end cutter. Practical implications On the study of CL data generation for a STL Model, most of the current studies are focused on the determination of the offset vectors of the vertexes. The offset distance is usually fixed to the radius of the cutter used. Thus, the overcut problem to the offset Model is inevitable and has not been much studied. The authors propose an effective approach to compensate the insufficient distance of the offset vertex and solve the overcut problem. Social implications The directly tool paths generation from a STL Model can reduce the error of surface reconstruction and speed up the machining progress. Originality/value The authors investigate the overcut problem occurred in vertex offset for CL data generation and present a new error compensation algorithm for generating the CL data that can effectively solve the overcut problem.
Hao Wen - One of the best experts on this subject based on the ideXlab platform.
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Polygonal Model based cutter location data generation with offset error compensation
Rapid Prototyping Journal, 2016Co-Authors: Hao Wen, Jian Gao, Xin ChenAbstract:Purpose As manufacturing technology has developed, digital Models from advanced measuring devices have been widely used in manufacturing sectors. To speed up the production cycle and reduce extra errors introduced in surface reconstruction processes, directly machining digital Models in the Polygonal stereolithographyformat has been considered as an effective approach in rapid digital manufacturing. In machining processes, Cutter Location (CL) data for numerical control (NC) machining is generated usually from an offset Model. This Model is created by offsetting each vertex of the original Model along its vertex vector. However, this method has the drawback of overcut to the offset Model. The purpose of this paper is to solve the overcut problem through an error compensation algorithm to the vertex offset Model. Design/methodology/approach Based on the analysis of the vertex offset method and the offset Model generated, the authors developed and implemented an error compensation method to correct the offset Models and generated the accurate CL data for the subsequent machining process. This error compensation method is verified through three Polygonal Models and the tool paths generated were used for a real part machining. Findings Based on the analysis of the vertex offset method and the offset Model generated, the authors developed an error compensation method to correct the offset Models and generated the accurate CL data for the subsequent machining process. The developed error compensation algorithm can effectively solve the overcut drawback of the vertex offset method. Research limitations/implications The error compensation method to the vertex offset Model is used for generating the CL data with the using of a ball-end cutter. Practical implications On the study of CL data generation for a STL Model, most of the current studies are focused on the determination of the offset vectors of the vertexes. The offset distance is usually fixed to the radius of the cutter used. Thus, the overcut problem to the offset Model is inevitable and has not been much studied. The authors propose an effective approach to compensate the insufficient distance of the offset vertex and solve the overcut problem. Social implications The directly tool paths generation from a STL Model can reduce the error of surface reconstruction and speed up the machining progress. Originality/value The authors investigate the overcut problem occurred in vertex offset for CL data generation and present a new error compensation algorithm for generating the CL data that can effectively solve the overcut problem.
Jian Gao - One of the best experts on this subject based on the ideXlab platform.
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Polygonal Model based cutter location data generation with offset error compensation
Rapid Prototyping Journal, 2016Co-Authors: Hao Wen, Jian Gao, Xin ChenAbstract:Purpose As manufacturing technology has developed, digital Models from advanced measuring devices have been widely used in manufacturing sectors. To speed up the production cycle and reduce extra errors introduced in surface reconstruction processes, directly machining digital Models in the Polygonal stereolithographyformat has been considered as an effective approach in rapid digital manufacturing. In machining processes, Cutter Location (CL) data for numerical control (NC) machining is generated usually from an offset Model. This Model is created by offsetting each vertex of the original Model along its vertex vector. However, this method has the drawback of overcut to the offset Model. The purpose of this paper is to solve the overcut problem through an error compensation algorithm to the vertex offset Model. Design/methodology/approach Based on the analysis of the vertex offset method and the offset Model generated, the authors developed and implemented an error compensation method to correct the offset Models and generated the accurate CL data for the subsequent machining process. This error compensation method is verified through three Polygonal Models and the tool paths generated were used for a real part machining. Findings Based on the analysis of the vertex offset method and the offset Model generated, the authors developed an error compensation method to correct the offset Models and generated the accurate CL data for the subsequent machining process. The developed error compensation algorithm can effectively solve the overcut drawback of the vertex offset method. Research limitations/implications The error compensation method to the vertex offset Model is used for generating the CL data with the using of a ball-end cutter. Practical implications On the study of CL data generation for a STL Model, most of the current studies are focused on the determination of the offset vectors of the vertexes. The offset distance is usually fixed to the radius of the cutter used. Thus, the overcut problem to the offset Model is inevitable and has not been much studied. The authors propose an effective approach to compensate the insufficient distance of the offset vertex and solve the overcut problem. Social implications The directly tool paths generation from a STL Model can reduce the error of surface reconstruction and speed up the machining progress. Originality/value The authors investigate the overcut problem occurred in vertex offset for CL data generation and present a new error compensation algorithm for generating the CL data that can effectively solve the overcut problem.