In precise measurement of objects, geometric characteristics widely use the phase-shifting interferometric systems. Simple data processingalgorithms are usually realized, but it is difficult to optimize such systems ...
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ISBN:
(纸本)0819422118
In precise measurement of objects, geometric characteristics widely use the phase-shifting interferometric systems. Simple data processingalgorithms are usually realized, but it is difficult to optimize such systems for accuracy increasing on general totality of measured data because of nonlinear data transformation. Besides that an important problem is the noise-immune phase unwrapping on intervals more than 2π rad. The proposed interferometric system is free from these disadvantages. In the system new method and algorithm of phase estimation are realized, which are based on Markov theory of optimal nonlinear filtering. The main advantages of proposed system are the following: data processing in real time scale, solving the phase unwrapping problem and minimization of phase errors in conditions of influence of phase fluctuations and noise correlated with the signal. Phase restoration error in typical measurement conditions dies not exceed 0.15 rad. on criterion peak- valley, while rms-error does not exceed 0.05 rad. The system provides the possibility to solve the synthesis and optimization problems of wide class of multidimensional, unstationary and nonlinear systems.
We propose vLSI architectures for implementing tree-structured image coding algorithms. A simple data partitioning and mapping technique is used for each processor to have a balanced work load and to work independentl...
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We propose vLSI architectures for implementing tree-structured image coding algorithms. A simple data partitioning and mapping technique is used for each processor to have a balanced work load and to work independently of each other. This technique leads to a simple memory access and processor architecture. The proposed parallel architecture has a high throughput rate and is area efficient. It can also be used to realize low-power designs.
The connection between fractal properties of sets and meromorphous continuation of some Dirichlet series is considered. Discrete orthogonal bases associated with fractal curves of the special type and fast algorithms ...
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The connection between fractal properties of sets and meromorphous continuation of some Dirichlet series is considered. Discrete orthogonal bases associated with fractal curves of the special type and fast algorithms of the spectral coefficients calculation are synthesized.
This paper studies image contrast and limiting visibility range of a small target observed against the background of the bottom of a water reservoir under active or passive illumination. We use the small-angle approxi...
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ISBN:
(纸本)0819421405
This paper studies image contrast and limiting visibility range of a small target observed against the background of the bottom of a water reservoir under active or passive illumination. We use the small-angle approximation of the radiative transfer theory to simulate analytically multiple scattered radiation from the target tracked and that from a water medium with taking the shadowing of the medium portion by the target into account. The contrast magnitude is shown to behave 'unusually' under certain conditions and grow up with submerging the target into water having even a maximum at some depth. The physical explanation of this maximum is given and the conditions for such an 'unusual' behavior of the contrast are evaluated. On the other hand, the target with certain albedo could be invisible over all depths starting from the water surface and don tot he bottom. The case of equal albedos of the target and bottom is also considered. The target is observable here at its location depth being smaller than some threshold value. We provide an analytical estimate of this value to derive it via optical characteristics of water. In addition, the results of some case studies are presented here for different optical characteristics of water medium. The obtained data would be useful for experts in the development of optical vision systems for small targets and in the simulation of the same by advanced algorithms for sensor signal and data processing.
In all papers published earlier the phase of the Fourier transform of an image was assumed to be known exactly. This assumption, however, is not valid in practice, since the image phase can be measured or processed on...
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In all papers published earlier the phase of the Fourier transform of an image was assumed to be known exactly. This assumption, however, is not valid in practice, since the image phase can be measured or processed only with some error. Owing to the essentially ill-posed nature of the restoration problem this error results in substantial undesired fluctuations in the solution, obtained both by known iterative and direct approaches. In this paper, the problem of restoration of images from their Fourier transform phases is considered as the ill-posed one that calls for using the corresponding regularization algorithms. The regularization algorithm is proposed that significantly improves an estimate of an image restored from the noisy phase.
A parallel algorithm of thinning binary images is developed that is based on the remote conversion. The algorithm is intended for realization on multiprocessor computer systems with distributed memory. The check made ...
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A parallel algorithm of thinning binary images is developed that is based on the remote conversion. The algorithm is intended for realization on multiprocessor computer systems with distributed memory. The check made on real images, shows its normal operation and efficiency. The given technique can be used for development of parallel skeletonization algorithms based on the remote conversion with other space measure.
This paper presents a target detection and interrogation techniques for a foveal automatic target recognition (ATR) system based on the hierarchical scale-space processing of imagery from a rectilinear tessellated mul...
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ISBN:
(纸本)0819421367
This paper presents a target detection and interrogation techniques for a foveal automatic target recognition (ATR) system based on the hierarchical scale-space processing of imagery from a rectilinear tessellated multiacuity retinotopology. Conventional machine vision captures imagery and applies early vision techniques with uniform resolution throughout the field-of-view (FOv). In contrast, foveal active vision features graded acuity imagers and processing coupled with context sensitive gaze control, analogous to that prevalent throughout vertebrate vision. Foveal vision can operate more efficiently in dynamic scenarios with localized relevance than uniform acuity vision because resolution is treated as a dynamically allocable resource. Foveal ATR exploits the difference between detection and recognition resolution requirements and sacrifices peripheral acuity to achieve a wider FOv (e.g. faster search), greater localized resolution where needed (e.g., more confident recognition at the fovea), and faster frame rates (e.g., more reliable tracking and navigation) without increasing processing requirements. The rectilinearity of the retinotopology supports a data structure that is a subset of the image pyramid. This structure lends itself to multiresolution and conventional 2-D algorithms, and features a shift invariance of perceived target shape that tolerates sensor pointing errors and supports multiresolution model-based techniques. The detection technique described in this paper searches for regions-of- interest (ROIs) using the foveal sensor's wide FOv peripheral vision. ROIs are initially detected using anisotropic diffusion filtering and expansion template matching to a multiscale Zernike polynomial-based target model. Each ROI is then interrogated to filter out false target ROIs by sequentially pointing a higher acuity region of the sensor at each ROI centroid and conducting a fractal dimension test that distinguishes targets from structured clutter.
Owing to the essentially ill-posed nature of the problem of restoration of finite signals and images from their Fourier transform phases, the error in the phase results in large undesired fluctuations in the solution,...
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ISBN:
(纸本)0780336291
Owing to the essentially ill-posed nature of the problem of restoration of finite signals and images from their Fourier transform phases, the error in the phase results in large undesired fluctuations in the solution, obtained both by known iterative and direct approaches. The problem of restoration of images from their noisy Fourier transform phases is addressed in relation to the existing solution methods. A new regularizing algorithm is proposed that significantly improves the estimate of an image restored from its noisy phase.
A unification of fast algorithms for the discrete Fourier transform is discussed. A relationship is established with the coverings of sets of input data indices and their metric properties with respect to the families...
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A unification of fast algorithms for the discrete Fourier transform is discussed. A relationship is established with the coverings of sets of input data indices and their metric properties with respect to the families of non-Archimedean metrics. An explicit analogy is given between the basic relations for the FFT-2 decomposition and the Stokes theorem on manifolds. Fast Fourier transforms with reduced computational complexity are synthesized.
Indexing multidimensional data is inherently complex leading to slow query processing. This behavior becomes more pronounced with the increase in database size and/or number of dimensions. In this paper we address thi...
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Indexing multidimensional data is inherently complex leading to slow query processing. This behavior becomes more pronounced with the increase in database size and/or number of dimensions. In this paper we address this issue by processing an index structure in parallel. First, we study different ways of partitioning an index structure. We then propose efficient algorithms for processing each query in parallel on the index structure. Using these strategies, we parallelized two multidimensional index structures-R* and LIB and evaluated the performance gains for the Gazetteer and the Catalog data of the Alexandria Digital Library on the Meiko CS-2.
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