TV constrained reconstruction could obtain perfect results from incomplete data, and has been applied to reduce metal artifact by assuming that the projection contaminated by metal is missing. In TV constrained recons...
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TV constrained reconstruction could obtain perfect results from incomplete data, and has been applied to reduce metal artifact by assuming that the projection contaminated by metal is missing. In TV constrained reconstruction, the selection of a proper step parameter for TV minimization procedure is a key point. However, this parameter is usually selected empirically, and it is a constant for all pixels in the whole image domain, regardless of the difference of missing projection quantity at different pixels. By analyzing the relationship between the missing projections and pixels position, a Weighted Total Variation (WTV) constrained reconstruction method is proposed to reduce metal artifact in this paper. For WTV constrained method, the parameters are no longer the same, but vary over image domain as the introduced information miss rate. The simulation results show that the proposed method is more effective than current TV constraint to reduce metal artifact. Moreover, WTV constrained method is extended to other incomplete projection problems.
It is well known that Approximated Maximum Likelihood(AML) estimator has the best performance for short time sampling wideband source bearing estimation. But for a long time, the heavy computational load of maximizing...
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Detecting boundary surface for the object of interest within 3D biomedical images is an important step towards understanding and quantitative analysis of the object. However, existing 3D edge detection techniques have...
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Detecting boundary surface for the object of interest within 3D biomedical images is an important step towards understanding and quantitative analysis of the object. However, existing 3D edge detection techniques have the limitations in detecting connected edge voxels and tracing undetected edge voxels from 3D images. In this paper, we propose a new strategy to detect boundary surface for the object of interest in 3D biomedical image. The new strategy utilizes the connectivity of boundary surface in the detection and tracing of edge voxels, and is much effective in overcoming the two limitations existing in 3D edge detectors. The performance and advantages of the proposed method are illustrated by many examples from different 3D biomedical images.
Aiming at the current structured P2P system's locality of physical location and accessing resources, in the context of P4P technology, this paper takes the Pastry and P4P-Pastry algorithms as foundation, proposes ...
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Aiming at the current structured P2P system's locality of physical location and accessing resources, in the context of P4P technology, this paper takes the Pastry and P4P-Pastry algorithms as foundation, proposes a enhanced P4P routing algorithm, in which peers performed clustering to the same resources and the proximity of physical location of nodes. When routing, the node routes to the nodes which are physical adjacent to it and have the lowest cost of communication. Theory analysis and the experimental results show that the algorithm proposed in this paper has realized localization download and greatly raised the data transfer rate, reduced the load in backbone network and enhanced the network performance.
Human facial shapes undergo significant variations from infancy to teenage, while they change limitedly as people age into adulthood. In this paper, facial shapes of males across ages using Euclidean distances are stu...
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This paper introduces a new algorithm for estimating camera pose from point correspondences. Generally, the pose problem is formulated as an optimization problem whose aim is to minimize the reprojection errors. Usual...
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This paper introduces a new algorithm for estimating camera pose from point correspondences. Generally, the pose problem is formulated as an optimization problem whose aim is to minimize the reprojection errors. Usually this kind of problem is non-convex and may get trapped in local minima. For dealing with this difficulty, we combine Branch and Bound with Linear Programming to generate a global optimal solution. We first use a branch-and-bound search over rotation space to find the best rotation and the problem can then be reduced to known fixed-rotation problems for which optimal solutions can be found by Linear Programming. The proposed method can obtain the global optimal solution and is very fast. It has been tested on a real data set and the results demonstrate the accuracy and high speed of this method.
This paper proposes a new method for feature extraction and recognition, namely, the fuzzy bidirectional maximum margin criterion (FBMMC) based on the maximum margin criterion and fuzzy set theory. In FBMMC, a members...
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This paper proposes a new method for feature extraction and recognition, namely, the fuzzy bidirectional maximum margin criterion (FBMMC) based on the maximum margin criterion and fuzzy set theory. In FBMMC, a membership grade matrix is calculated by the FKNN algorithm, and then the membership grades are incorporated into the formulation of the scatter matrices to formulate the row and column directional fuzzy scatter matrices. Using the fuzzy scatter matrix, FBMMC performs fuzzy image MMC in the row and column directions simultaneously. Experiments on the ORL and Yale face databases show the effectiveness of the proposed FBMMC based feature extraction method.
Theories of spread spectrum communications, channel coding, capacity analysis techniques have been widely applied in digital watermarking research. In recent years, communication theory has made an important technolog...
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Theories of spread spectrum communications, channel coding, capacity analysis techniques have been widely applied in digital watermarking research. In recent years, communication theory has made an important technological breakthrough. The next generation mobile communication systems (4G) is far exceeding the capacity needs of the traditional Shannon channel capacity limit, and this need promotes the rapid development of multiple-input multiple-output (MIMO) technology. The combination of space-time coding and MIMO technology will breakthrough the capacity limit of single-input single-output (SISO) channel. In this paper, the digital image watermarking system is extended from SISO to MIMO systems based on space-time coding and MIMO communication theory. The new watermarking algorithm is designed in the new framework of space-time coding and MIMO-based communication theory. The watermark capacity and the detection error rate also are further studied under the conditions of different space-time coding. These studies will provide a new idea for the design of new digital watermarking algorithm.
By introducing a novel membership constraint function, a new algorithm called fuzzy c-means switching regression model with generalized improved fuzzy partitions (GIFP-FCRM) is proposed. This algorithm seems less sens...
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