A new type of two-dimensional formal grammars known as 'Multilevel Array Grammars' (MLAG) is introduced. This is based on the extention of concepts used in Array Grammars as defined by Milgram and Rosenfeld. I...
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A new type of two-dimensional formal grammars known as 'Multilevel Array Grammars' (MLAG) is introduced. This is based on the extention of concepts used in Array Grammars as defined by Milgram and Rosenfeld. In these grammars, the 'terminal symbols' of a grammar defined at a higher level ( greater than 0) are themselves patterns of a specified shape, which, in turn, are derived from the grammars defined at lower level. These 'terminal symbols' can be viewed as 'floor tiles' which are laid according to the rewriting rules in generating a two-dimensional texture scene. These grammars are shown to be adequate to generate texture scenes that can be viewed at many levels, such as ″brick wall type″ textures.
An approach to feature detection in image approximation networks is presented. The network is an approximation of the image data surface. The extraction of global image features from the network is described. Primitiv...
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An approach to feature detection in image approximation networks is presented. The network is an approximation of the image data surface. The extraction of global image features from the network is described. Primitive features such as peaks and valleys are located, then ridges and valley lines are traced by iteratively exploring neighboring points of detected features. These topographical features provide a region segmentation of the image. The region boundaries represent global charcteristics of the image data.
The nearest-neighbor and potential function decision rules are nonparametric techniques that partition the feature space based on a set of labelled sample points. Determining whether the partitions of the two rules ar...
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The nearest-neighbor and potential function decision rules are nonparametric techniques that partition the feature space based on a set of labelled sample points. Determining whether the partitions of the two rules are identical for a given set of points is an interesting problem in computational geometry. A relationship between the two methods in terms of subclasses and composite classes is developed. Considering an exponential potential function, necessary and sufficient conditions for identity of their decision surfaces are obtained. Based on conditions of symmetry, weighting, and the Voronoi region of a point, an algorithm for establishing identity in R**d is introduced.
Because of the increasing demand for cytogenetic analysis, machine assisted karyotyping of human chromosomes is almost a necessity. One of the most important phases in chromosome analysis and other related histo- or c...
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Because of the increasing demand for cytogenetic analysis, machine assisted karyotyping of human chromosomes is almost a necessity. One of the most important phases in chromosome analysis and other related histo- or cytochemistry work is the scanning of microscopic slides to detect suitable metaphases or cells. In this paper such a system is described based on the use of microprocessors, a digitally controlled microscope, and video hardware for autofocus, thresholding and feature extraction. A hierarchically structured search procedure has excellent results at a scanning speed of 0. 5 cm**2/min.
The shape of a two-dimensional contour can be conveniently transformed into an amplitude-vs-distance signal by allowing a line segment of specified length to trace out the contour and recording the angular variation o...
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The shape of a two-dimensional contour can be conveniently transformed into an amplitude-vs-distance signal by allowing a line segment of specified length to trace out the contour and recording the angular variation of the line segment as a function of distance along the contour. The line segment, which connects two points on the contour, may be of strictly fixed length or may span a fixed number of links in a chain-coded representation of the contour. The contour may be closed or open. The record of angular variation (i. e. , the incremental curvature) is independent of the orientation of the contour and can also be made independent of scale.
A hardware array processor designed principally for imageprocessing applications, called BASE 8, has been developed. BASE 8 has the appearance of a fully parallel Binary Array processor to the programmer, however it ...
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A hardware array processor designed principally for imageprocessing applications, called BASE 8, has been developed. BASE 8 has the appearance of a fully parallel Binary Array processor to the programmer, however it processes a large array in a sequence of 8 multiplied by 8 blocks. A BASE 8 processor is designed to be connected to and controlled by a minicomputer such as a PDP 11. It greatly enhances the performance of the host computer for some imageprocessing algorithms and also provides a flexible hardware model for Binary Array processor architecture research. The hardware organization of BASE 8 is described and its performance for some imageprocessing algorithms is given.
A picture digitization grid based on logarithmic spirals rather than Cartesian coordinates is presented. Expressing this curvilinear grid as a conformal exponential mapping reveals useful imageprocessing properties. ...
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A picture digitization grid based on logarithmic spirals rather than Cartesian coordinates is presented. Expressing this curvilinear grid as a conformal exponential mapping reveals useful imageprocessing properties. The mapping induces a computational simplification that suggests parallel architectures in which most geometric transformations are effected by data shifting in memory rather than arithmetic on coordinates. These include fast, parallel noise-free rotation, scaling, and some projective transformations of pixel defined images. conformality of the mapping preserves local picture-processing operations such as edge detection.
It is shown that the Hough transform may be used for encoding of line curves and waveforms that consist of the concatenation of curves from an underlying set of families of curves. Several properties of the transform ...
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It is shown that the Hough transform may be used for encoding of line curves and waveforms that consist of the concatenation of curves from an underlying set of families of curves. Several properties of the transform are given in this context.
Large images are becoming more and more common in earth resources monitoring, medical diagnosis and other applications. Often it would be helpful to work with only a subset of a large image since less space and time w...
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Large images are becoming more and more common in earth resources monitoring, medical diagnosis and other applications. Often it would be helpful to work with only a subset of a large image since less space and time would be required to process it. Subsets extracted according to semantic attributes have irregular shapes and as such are awkward to store and process. Irregular subsets can be covered with rectangular regions to simplify the regions to be stored and processed. Then the rectangular regions must be organized with an index. Here several covering methods are compared and indexing methods suggested. A surprizing result is that the sequential-greatest coverage heuristic can lead to arbitrarily bad coverings in some situations. However, this disadvantage can be overcome by combination with a tiling approach.
Shape description and recognition is an important and interesting problem in scene analysis. The authors approach to shape description is a formal model of a shape consisting of a set of primitives, their properties, ...
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Shape description and recognition is an important and interesting problem in scene analysis. The authors approach to shape description is a formal model of a shape consisting of a set of primitives, their properties, and their interrelationships. The primitives are the simple parts and intrusions of the shape which can be derived through the graph-theoretic clustering procedure previously described. The interrelationships are two ternary relations on the primitives: the intrusion relation which relates two simple parts that join to the intrusion they surround and the protrusion relation which relates two intrusions to the protrusion between them. Using this model, a shape matching procedure that uses a tree search with look-ahead to find mappings from a prototype shape to a candidate shape has been developed.
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