An optimal decision rule has been derived by Chair and Varshney (1986) for fusing decisions based on the Bayesian criterion. However, to implement such a rule, the miss probability P-M and the probability of false ala...
详细信息
An optimal decision rule has been derived by Chair and Varshney (1986) for fusing decisions based on the Bayesian criterion. However, to implement such a rule, the miss probability P-M and the probability of false alarm P-F for each local detector must be known, and these are not readily available in practice. To circumvent this situation, an adaptive fusion system for equiprobable sources has been developed. The system is extended to unequiprobable sources;thus its practicality is enhanced. An adaptive fusion model using the fusion result as a supervisor to estimate the P-M and P-F is introduced. The fusion results are classified as 'reliable' and 'unreliable', Reliable results are used as a reference to update the weights in the fusion centre. Unreliable results are discarded. The convergence and error analysis of the system are demonstrated theoretically and by simulations. The paper concludes with simulation results that conform to the analysis.
An object-based stereo image coding algorithm is proposed. The algorithm relies on modeling of the object structure using 3-D wire-frame models and motion estimation using globally rigid and locally deformable motion ...
详细信息
An object-based stereo image coding algorithm is proposed. The algorithm relies on modeling of the object structure using 3-D wire-frame models and motion estimation using globally rigid and locally deformable motion models. Algorithms for the estimation of motion and structure parameters from stereo images are described. Motion parameters are used to construct predicted images by mapping the image texture on the object surface. Coding of object parameters, appearing background regions, and prediction errors are investigated, and experimental results with standard stereo image sequences depicting general scenes are presented. The proposed algorithm is seen to be very efficient for applications such as stereoscopic video transmission. Furthermore, it is especially well suited to advanced applications such as generation and transmission of intermediate views for multiview receiver systems and applications in which object-wise editing of the bit stream is required. The latter include video production using preanalyzed scenes and virtual reality applications.
A rate-distortion framework is used to define a very low bit-rate coding scheme based on quadtree segmentation and optimized selection of motion estimators, This technique achieves maximum reconstructed image quality ...
详细信息
A rate-distortion framework is used to define a very low bit-rate coding scheme based on quadtree segmentation and optimized selection of motion estimators, This technique achieves maximum reconstructed image quality under the constraint of a target bit rate for the coding of the vector field and segmentation information, First, a complete scheme is proposed for hybrid two-dimensional (2-D) and three-dimensional (3-D) motion estimation and compensation, The quadtree object segmentation is optimized for hybrid motion estimation in the rate-distortion sense, This scheme adapts to the depth of the quadtree and the technique used for motion estimation for each leaf of the tree. A more sophisticated technique, adapted to the requirements of a very low bit-rate coder, is also proposed which also considers the transmission of the prediction error corresponding to the particular choice of the motion estimator, Based on these coding schemes, two versions of a very low bit-rate image sequence coder are developed, Experimental results illustrating the performance of the proposed techniques in very low bit-rate image sequence coding application areas are presented and evaluated.
The ability of a parallel algorithm to make efficient use of increasing computational resources is known as its scalability. In this paper, we develop four parallel algorithms for the 2-dimensional Discrete Wavelet Tr...
详细信息
The ability of a parallel algorithm to make efficient use of increasing computational resources is known as its scalability. In this paper, we develop four parallel algorithms for the 2-dimensional Discrete Wavelet Transform algorithm (2-D DWT), and derive their scalability properties on Mesh and Hypercube interconnection networks. We consider two versions of the 2-D DWT algorithm, known as the Standard (S) and Non-standard (NS) forms, mapped onto P processors under two data partitioning schemes, namely checkerboard (CP) and stripped (SP) partitioning. The two checkerboard partitioned algorithms on the cut-through-routed (CT-routed) Mesh are scalable as M(2) = Omega(P log P) (Non-standard form, NS-CP), and as M(2) = Omega(P log(2) P) (Standard form, S-CP);while on the store-and-forward-routed (SF-routed) Mesh and Hypercube they are scalable as M(2) = Omega(P-3/3-gamma) (NS-CP), and as M(2) = Omega (P-2/2-gamma) (S-CP), respectively, where M(2) is the number of elements in the input matrix, and gamma is an element of (0, 1) is a parameter relating M to the number of desired octaves J as J = [gamma log M]. On the CT-routed Hypercube, scalability of the NS-form algorithms shows similar behavior as on the CT-routed Mesh. The Standard form algorithm with stripped partitioning (S-SP) is scalable on the CT-routed Hypercube as M(2) = Omega(P-2), and it is unscalable on the CT-routed Mesh. Although asymptotically the stripped partitioned algorithm S-SP on the CT-routed Hypercube would appear to be inferior to its checkerboard counterpart S-CP, detailed analysis based on the proportionality constants of the isoefficiency function shows that S-SP is actually more efficient than S-CP over a realistic range of machine and problem sizes. A milder form of this result holds on the CT- and SF-routed Mesh, where S-SP would, asymptotically, appear to be altogether unscalable.
In this paper we integrate motion and structure estimation in order to exploit their coherence. We propose an algorithm that uses models for object surfaces and their motion and estimates the model parameters using th...
详细信息
In this paper we integrate motion and structure estimation in order to exploit their coherence. We propose an algorithm that uses models for object surfaces and their motion and estimates the model parameters using the image intensity matching criterion. The visible scene surface is represented with a parametrically deformable, spatially adaptive, wireframe model. Object motion is first modeled using the well-known rigid motion assumption along with the quaternion rotation representation. Nonrigid motion modeling using the finite element technique is also investigated as an alternative to rigid motion modeling or as a refinement of it. A functional containing image matching and surface smoothness constraints is minimized with respect to the unknown model parameters. A discontinuity detection scheme allowing deactivation of smoothness constraints across object boundaries, is investigated. A regularization scheme using a coarse to fine strategy is employed. (C) 1997 Academic Press.
In this paper we propose an object-based stereo image coding algorithm. The algorithm relies on modeling of the object structure using 3D wire-frame models, and motion estimation using globally rigid and locally defor...
详细信息
In this paper we propose an object-based stereo image coding algorithm. The algorithm relies on modeling of the object structure using 3D wire-frame models, and motion estimation using globally rigid and locally deformable motion models. Algorithms for the estimation of motion and structure parameters from stereo images are described. Motion parameters are used to construct predicted images at subsequent time instances by mapping the image texture on the object surface. Coding of object parameters, appearing background regions and prediction errors is investigated and experimental results with video-conference scenes are presented. The proposed algorithm is very efficient for applications like stereoscopic video transmission, and is especially suited to advanced applications such as generation and transmission of intermediate views for multiview receiver systems, as well as applications in which an object-wise editing of the bit-stream is required, such as video-production using preanalysed scenes or virtual reality applications.
We consider a distributed system where sensors make location parameter estimates using their observations. A central processor collects the local estimates and declares a final estimate based on them. We present a sim...
详细信息
We consider a distributed system where sensors make location parameter estimates using their observations. A central processor collects the local estimates and declares a final estimate based on them. We present a simple study of the convergence properties of three structures where empirical mean and M-estimates are used in various combinations. It is shown that when occasional outliers exist, decentralized estimators that provide robustness at stages where data corruption occurs perform superiorly. (C) 1997 Elsevier Science B.V.
The maturing of telecommunication technologies has ushered in a whole new era of applications and services in the health care environment. Teleworking, teleconsultation, multimedia conferencing and medical data distri...
详细信息
The maturing of telecommunication technologies has ushered in a whole new era of applications and services in the health care environment. Teleworking, teleconsultation, multimedia conferencing and medical data distribution are rapidly becoming commonplace in clinical practice. As a result, a set of problems arises, concerning data confidentiality and integrity. Public computer networks, such as the emerging ISDN technology, are vulnerable to eavesdropping. Therefore it is important for telemedicine applications to employ end-re-end encryption mechanisms securing the data channel from unauthorized access or modification. We propose a network access and encryption system that is both economical and easily implemented for integration in developing or existing applications, using well-known and thoroughly tested encryption algorithms. Public-key cryptography is used for session-key exchange, while symmetric algorithms are used for bulk encryption. Mechanisms for session-key generation and exchange are also provided.
A 1.5V resistive fuse for image smoothing and segmentation using bulk-driven MOSFETs is presented. The circuit switches on only if the differential voltage applied across its input terminals is less than a set voltage...
详细信息
A 1.5V resistive fuse for image smoothing and segmentation using bulk-driven MOSFETs is presented. The circuit switches on only if the differential voltage applied across its input terminals is less than a set voltage;it switches off if the differential voltage is higher than the set value. The useful operation range of the circuit is 0.4V with a supply voltage of 1.5V and threshold voltages of V-Tn = 0.828V and V-Tp = -0.56V for n and g channel MOSFETs, respectively.
Orthogonal transmultiplexers have been successfully utilized for multiuser communications. They are of the FDMA type in their most common version. The transmultiplexers using frequency selective PR-QMF's as their ...
详细信息
Orthogonal transmultiplexers have been successfully utilized for multiuser communications. They are of the FDMA type in their most common version. The transmultiplexers using frequency selective PR-QMF's as their user codes were reported in the literature. This approach conflicts with the requirements of a CDMA communications system. We introduce novel spread spectrum PR-QMF codes in this correspondence, wherein the orthogonality is distributed over both time and frequency domains. It is shown that the proposed multivalued spread spectrum PR-QMF codes with minimized auto and cross-correlation properties outperform the conventional binary Gold codes in CDMA communication scenarios considered in the correspondence.
暂无评论