Presents a method to compute the inter-frame transformation between two range image views of complex multi-part objects. No exact feature matching is attempted and no initial approximate transformation is provided. Th...
详细信息
Presents a method to compute the inter-frame transformation between two range image views of complex multi-part objects. No exact feature matching is attempted and no initial approximate transformation is provided. The method is naturally decomposed into two stages of initial estimation and final refinement of the transformation. A hierarchical triangulation-based surface representation provides an efficient way to select the control points at which the alignment of the two surfaces is to be evaluated. This representation also permits the selection of a manageable number of initial transformations among which at least one is to be in the parametric neighborhood of the actual transformation. Experimental results show that the computed transformation between two views of a complex multi-part object may provide angles of rotation within a fraction of a degree of the actual ones.< >
The authors develop an empirical measure for the selection of the Gaussian filter that is commonly used for edge enhancement. The measure is based totally on the image at hand. Edge enhancement by a Gaussian filter ha...
详细信息
The authors develop an empirical measure for the selection of the Gaussian filter that is commonly used for edge enhancement. The measure is based totally on the image at hand. Edge enhancement by a Gaussian filter has two distinct advantages: (1) the filter is fully described by a single parameter, the standard deviation sigma ; (2) the two-dimensional filter is separable and can be easily implemented. The filter's spatial support is a function of sigma . This support is normally in the range of +or-3.5 sigma . An empirical measure is described for the selection of the Gaussian filter's spatial support using the power spectrum density of the input image. Classic Fourier analysis is used to obtain a measure for the spatial support of the Gaussian filter given a particular image. Experimental results suggest that this measure can be used as an aid in deciding the Gaussian filter's spatial support needed to enhance the edges.< >
A new layered representation of images is proposed using, what one may call, vector wavelets defined by generalized Hermite polynomials. This representation has some special properties: it is distinct from and superio...
详细信息
A new layered representation of images is proposed using, what one may call, vector wavelets defined by generalized Hermite polynomials. This representation has some special properties: it is distinct from and superior to the other wavelet schemes of the literature; it is stable; it transforms the image into matrices of coefficients in the same manner as the standard transforms (Fourier, Hadamard and others), but at the specified 'scales'; the zero-crossings of the signal at various scales can be directly obtained from the coefficients; and the size of the resolution cell in the 'phase-space' is variable even at a specified scale, depending on the image being analysed. This representation has been successfully applied to different types of images, both synthetic and natural.< >
An edge detection technique that optimizes edge localization while providing edge continuity and edge thinning is introduced. The solution is obtained by annealing a mean field neural network, providing inexpensive so...
详细信息
An edge detection technique that optimizes edge localization while providing edge continuity and edge thinning is introduced. The solution is obtained by annealing a mean field neural network, providing inexpensive solutions with high parameter insensitivity. Anisotropic diffusion is used to provide localized edge data through the scale-space. analysis of network parameters, diffusion parameters, network convergence, and scale-space equivalence is provided. Results are shown for real image data and compared with the results of other important edge detection schemes.< >
A mathematical framework for the solution of statistical inference problems on a class of random sets is proposed. It is based on a new definition of expected pattern. The least-mean-difference estimator (restoration ...
详细信息
A mathematical framework for the solution of statistical inference problems on a class of random sets is proposed. It is based on a new definition of expected pattern. The least-mean-difference estimator (restoration filter) is proved, under certain conditions, to be equivalent to the minimization of the measure of size (area) of the set-difference between the original pattern and the expected pattern of the estimated (restored) pattern. Consequently, it is proved that, under certain conditions, if the estimator (restoration filter) is unbiased, then it is the least mean difference estimator (restoration filter).< >
In this paper we present some enlightening results to show why and how stability assessment for Linear Time-Varying (LTV) systems based solely on the location of the "frozen-time eigenvalues (FTE)" fails to ...
详细信息
In this paper we present some enlightening results to show why and how stability assessment for Linear Time-Varying (LTV) systems based solely on the location of the "frozen-time eigenvalues (FTE)" fails to be sufficient or necessary, using two classes of parametrized periodic LTV systems derived from two examples given by Markus-Yamabe [6] and Wu [11]. Exact domain of stability in the parameter space obtained using analytical or numerical solutions of the Floquet characteristic Exponents are presented, and compared to that predicted by FTEs. The results are useful in the study of robustness and stabilization of Linear Time Invariant (LTI) systems, as will be shown in this paper that an unstable LTI system maybe stabilized or destabilized by periodic structural perturbations (pumping) without any control input.
We present a general theory for the morphological representation of discrete and binary images. The basis of this theory relies upon the generation of a set of nonoverlapping segments of an image via repeated erosions...
详细信息
We present a general theory for the morphological representation of discrete and binary images. The basis of this theory relies upon the generation of a set of nonoverlapping segments of an image via repeated erosions and set transformations, which in turn produces a decomposition that guarantees exact reconstruction. We introduce a general morphological representation and we study its properties. We also investigate the relationship between the proposed representation and some existing shape analysis tools (e.g., discrete size transform, pattern spectrum, skeletons), thus introducing the representation as the basis of a unified theory for geometrical imageanalysis. Particular cases of the general representation scheme are shown to yield a number of useful image decompositions which are directly related to various forms of morphological skeletons. We study the relationship between the representation and the various forms of morphological skeletons. As a result of this study we develop a unified theory for the mathematical description of the morphological skeleton decomposition of discrete and binary images.
A critical issue in classification tree design is obtaining right-sized trees, i.e., trees which neither underfit nor overfit the data. Instead of using stopping rules to halt partitioning, we follow the approach of g...
详细信息
A critical issue in classification tree design is obtaining right-sized trees, i.e., trees which neither underfit nor overfit the data. Instead of using stopping rules to halt partitioning, we follow the approach of growing a large tree with pure terminal nodes and selectively pruning it back. A new efficient iterative method is proposed to grow and prune classification trees. This method divides the data sample into two subsets and iteratively grows a tree with one subset and prunes it with the other subset, successively interchanging the roles of the two subsets. The convergence and other properties of the algorithm are established. Theoretical and practical considerations suggest that the iterative tree growing and pruning algorithm should perform better and require less computation than other widely used tree growing and pruning algorithms. Numerical results on a waveform recognition problem are presented to support this view.
暂无评论