Showing papers on "Structuring element published in 1993"
TL;DR: An approach to QRS complex detection based on mathematical morphology is presented, which works as a peak-valley extractor and it is controlled by the shape of the structuring element, resulting in very fast execution times.
Abstract: An approach to QRS complex detection based on mathematical morphology is presented. QRS complexes are detected by the application of a simple morphological operator. This operator works as a peak-valley extractor and it is controlled by the shape of the structuring element. A set (horizontal line segment) is used as a structuring element, resulting in very fast execution times. The accuracy of this approach has been tested using a standard ECG library; a sensitivity of 99.38% and a positive predictivity of 99.48% have been achieved. >
213 citations
TL;DR: It is shown that a combination of the mathematical morphology operation, opening, with a linear rotating structuring element (ROSE) and dual feature thresholding can semi-automatically segment categories of vessels in a vascular network.
Abstract: A method for measuring the spatial concentration of specific categories of vessels in a vascular network consisting of vessels of several diameters, lengths, and orientations is demonstrated. It is shown that a combination of the mathematical morphology operation, opening, with a linear rotating structuring element (ROSE) and dual feature thresholding can semi-automatically segment categories of vessels in a vascular network. Capillaries and larger vessels (arterioles and venules) are segmented here in order to assess their spatial concentrations. The ROSE algorithm generates the initial segmentation, and dual feature thresholding provides a means of eliminating the nonedge artifact pixels. The subsequent gray-scale histogram of only the edge pixels yields the correct segmentation threshold value. This image processing strategy is demonstrated on micrographs of vascular casts. By adjusting the structuring element and rotation angles, it could be applied to other network structures where a segmentation by network component categories is advantageous, but where the objects can have any orientation. >
93 citations
11 May 1993
TL;DR: It is asserted that mathematical morphology operations with a convex structuring element are captured by a differential deformation of the boundary along the normal, governed by a Hamilton-Jacobi partial differential equation (PDE).
Abstract: The authors complement the standard algebraic view of mathematical morphology with a geometric, differential view. Three observations underlie this approach. (1) Certain structuring elements (convex) are scalable in that a sequence of repeated operations is equivalent to a single operation, but with a larger structuring element of the same shape. (2) To determine the outcome of the operation, it is sufficient to consider how the boundary is modified. (3) The modifications of the boundary are such that each point can be moved along the normal by a certain amount, which is dependent on the structuring element. Taken together, these observations, when the size of the structuring element shrinks to zero, assert that mathematical morphology operations with a convex structuring element are captured by a differential deformation of the boundary along the normal, governed by a Hamilton-Jacobi partial differential equation (PDE). A second theme is to show that mathematical morphology operations can be numerically implemented in a highly accurate fashion as the solution of these PDEs. >
58 citations
TL;DR: A novel shape description method based on the multiresolution morphological image processing by non-convex multiple structuring elements that is robust against noise and invariant to both rotation and scale change is presented.
27 citations
TL;DR: A morphological optoelectronic image processor based on the threshold decomposition concept is described and demonstrated and examples of processing an input image of 256 x 256 pixels and 16 gray levels with kernels of arbitrary size are presented.
Abstract: A morphological optoelectronic image processor based on the threshold decomposition concept is described and demonstrated. Binary slices of a gray-scale input image are optically convolved with a binary structuring element of arbitrary size and shape in a noncoherent convolver. The slices are displayed on a liquid-crystal spatial light modulator of 320 × 264 pixels. The kernels are implemented as modifications of the system impulse response. The processor’s convolution patterns are recorded with a CCD camera and fed into a PC by a frame grabber. Subsequent elementary morphological operations are looped. Examples of processing an input image of 256 × 256 pixels and 16 gray levels with kernels of arbitrary size are presented.
22 citations
27 Apr 1993
TL;DR: In this article, a linear combination of morphological operators can be formed to alleviate the bias introduced by the individual morphological operator, and the LOCO filter is the best of these at reducing impulses and noise.
Abstract: It is shown how linear combinations of morphological operators can be formed to alleviate the bias introduced by the individual morphological operators. Since every morphological operator has a complementary operator that is equally and oppositely biased, the authors propose averaging the complementary operators to alleviate the bias. Of the three filters formed by averaging the standard morphological operators, two are the previously defined midrange filter, and pseudomedian filter, while one is a new filter, called the LOCO filter. Under most conditions, the LOCO filter is the best of these at reducing impulses and noise., Linear combinations of morphological operators allow the shape control of the morphological filters (exerted by the selection of a structuring element) without introducing bias. For example, the LOCO filter with a square structuring element preserves 90 degrees corners in an image while reducing noise almost as well as the square-shaped medium filter, which rounds off such corners. >
15 citations
TL;DR: Important deterministic properties of root signals of morphological opening, closing, open-closing and clos-opening are derived leading to a complete characterization of output signals of these morphological filters.
7 citations
27 Apr 1993
TL;DR: It is shown that, using grayscale morphology and a set of functions related to orthogonal polynomials-defined on a window-as structuring elements, a signal representation analogous to the polynomial transform can be developed.
Abstract: It is shown that, using grayscale morphology and a set of functions related to orthogonal polynomials-defined on a window-as structuring elements, a signal representation analogous to the polynomial transform can be developed. The geometric decomposition of a signal is achieved by windowing and using a morphological opening operation to approximate the windowed signal with each of the structuring elements. The resulting representation is made to resemble an orthogonal expansion by constraining the result of opening to be equal to the structuring function. Properties of the recursive decomposition algorithm make it possible to develop an algorithm for calculating a set of coefficients used in the reconstruction. The analysis and synthesis of one-dimensional signals are illustrated with an image data compression example. >
5 citations
TL;DR: The developed techniques can be applied to decompose the structuring element into successive dilation of small structuring elements with window size 3 × 3.
5 citations
23 Jun 1993
TL;DR: A novel method for optimal shape description based on the multiresolution morphological image processing is presented and the optimal structuring element is determined that will enable best discrimination of object shapes.
Abstract: A novel method for optimal shape description based on the multiresolution morphological image processing is presented in this paper. The method is optimal in the sense that the optimal structuring element is determined that will enable best discrimination of object shapes. In this method a representation based on the areas of the input binary image successively eroded by multiple rotated structuring elements at different resolutions is used. For a given set of model shapes the optimal structuring element is selected by a means of genetic algorithm. The optimization criteria is formulated to enable a robust shape matching. Experiments have been performed on a set of model shapes. Genetic algorithm was used to create new generations of structuring elements by crossing over the genes which represent structuring elements. The result of the iterative procedure is the optimal structuring element which was used for shape description using the morphological signature transform. The proposed optimal shape representation method is applied to the problem of shape matching which evolves in many object recognition applications. Here, an unknown object from the input image is matched to a set of known objects in order to classify it into one of finite number of possible classes. Experimental results are presented and discussed.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
5 citations
28 Oct 1993
TL;DR: The 3-D registration of magnetic resonance (MR) and positron emission tomographic (PET) images of the brain is of significant interest for various reasons and a new MR and PET brain registration procedure based on the iterative principal axis transform (IPAR) and the morphological signature transform is presented.
Abstract: The 3-D registration of magnetic resonance (MR) and positron emission tomographic (PET) images of the brain is of significant interest for various reasons. A new MR and PET brain registration procedure is presented here. The procedure is based on the iterative principal axis transform (IPAR) and the optimal shape description method based on the morphological signature transform. The morphological processing is used to improve the accuracy of the basic IPAR method. A genetic algorithm is used to select a near-optimal structuring element for MST-based registration. The results demonstrate that the method provides an accurate registration. >
12 Jan 1993
TL;DR: A novel two-dimensional thresholding photodetector array, capable of performing parallel thresholding and feedback, is utilized in this system and makes possible the implementation of many complex morphological operations requiring iterative feedbacks and full programmability.
Abstract: An innovative optically implemented morphological processor is introduced. With the use of a large space-bandwidth-product Dammann grating and a high-speed shutter spatial light modulator, effective structuring element with large size and arbitrary shape can be constructed with dynamic reconfigurability. This reconfigurability is a major improvement over the conventional correlator-based morphological processor in which fixed holographic filters are used as structuring elements (Casasent and Botha, 1988). A novel two-dimensional thresholding photodetector array, capable of performing parallel thresholding and feedback, is utilized in this system and makes possible the implementation of many complex morphological operations requiring iterative feedbacks and full programmability. The optical architecture and the principle of operation are presented. Experimental demonstration of binary image morphological erosion, dilation, opening, and closing are also demonstrated. A technique for extending this technique to gray-scale image using thresholding decomposition technique is also discussed.
21 May 1993
TL;DR: In this article, a search procedure was proposed to find a structuring element for dilation that is optimal in the sense of minimizing the mean Hausdorf error, where the utility function is based on the calculation of certain probabilities related to the noise model.
Abstract: This paper analyzes restoration of subtractive noise on a binary image by a single morphological operation, dilation. Restoration by dilation alone is appropriate under particular explicitly defined random noise models, based respectively on erosion, independent pixel subtractive noise, and independent pixel subtractive noise followed by dilation. Since in general it is not possible to perfectly restore subtractive noise we use the Hausdorf metric to measure the residual error in restoration. This metric is the appropriate one because of its geometric interpretation in terms of set coverings. We describe a search procedure to find a structuring element for dilation that is optimal in the sense of minimizing the mean Hausdorf error. The search procedure's utility function is based on the calculation of certain probabilities related to the noise model, namely the probability of one set being the subset of another set and some related probabilities.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
23 Jun 1993
TL;DR: This paper presents a fast algorithm for the computation of the anti-granulometry by closings which avoids boundary effects based on a simple geometric transformation called the `Steiner Inverse Transform', on which original theoretical results are given.
Abstract: The principle of shape recognition by using granulometries, is to transform a binary planar shape into a curve which is translation, rotation and scale invariant by a family of morphological transformations depending on the size of the structuring element. This paper presents a fast algorithm for the computation of the anti-granulometry by closings which avoids boundary effects. This algorithm is based on a simple geometric transformation called the `Steiner Inverse Transform', on which original theoretical results are given.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
22 Oct 1993
TL;DR: A solution taking advantage of overlapping areas of the structuring elements and involving either a hiearchical approach or a simple sort of the pixels of the image is described, along with a comparison of this algorithm with existing methods.
Abstract: This paper presents efficient algorithms to perform standard morphological operations on gray-level images such as erosions and dilations with any structuring elements In a first section the general case is studied A solution taking advantage of overlapping areas of the structuring elements and involving either a hiearchical approach or a simple sort of the pixels of the image is described, along with a comparison of this algorithm with existing methods The proposed method shows significant improvement over these methods Some mean of accelerating the algorithm further are also indicated In a second section, the particular case of the line segment as structuring element is studied and a new method for dealing with these structuring elements, oriented in any direction, is proposed, which features a constant, optimal computing time with respect to the length of these structuring elements Extensions to other types of structuring elements using the described technique are also proposed© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering Downloading of the abstract is permitted for personal use only
Journal Article•
TL;DR: The LOCO filter is devised that provides the shape control and noise suppression of morphological techniques without biasing the image and will demonstrate the effects of different structuring element shapes on thermographic images of tissue heated by laser irradiation and electrosurgery.
Abstract: Mathematical morphology is a set algebra that defines some important new techniques in image processing. Morphological filters are closely related to order statistic and other nonlinear filters, but they are uniquely sensitive to shape. A morphological filter will preserve shapes similar to its structuring element shape while modifying dissimilar shapes. Most morphological filters are effective at removing both linear and nonlinear noise processes. However, the standard morphological operators introduce a statistical and deterministic bias to images. Fortunately, these operators exist in complementary pairs that are equally and oppositely biased. One way to alleviate the bias is to average the two complementary operators. The filters formed by such averages are the midrange filter (basic operators), the pseudomedian filter (singly compound operators) and the LOCO filter (doubly compound operators). In thermographic imaging, one often wishes to find exact temperatures or accurate isothermal contours. Therefore, techniques used to remove sensor noise and scanning artifact should not introduce bias. The LOCO filter that we have devised provides the shape control and noise suppression of morphological techniques without biasing the image. We will demonstrate the effects of different structuring element shapes on thermographic images of tissue heated by laser irradiation and electrosurgery.
01 Jan 1993
TL;DR: A necessary condition for block edge detection based on a hierarchical representation of the conjugate classification for the hexagonal grid is investigated and a speed-up ratio of more than 6–11 compared with the same activity performed by a standard implementation of mathematical morphology is observed.
Abstract: A necessary condition for block edge detection based on a hierarchical representation of the conjugate classification for the hexagonal grid is investigated in this paper. Constructing the operations of block edge detection, it is necessary to collect a set of 48 states as the structuring elements. To represent the selected state set, five hierarchical representations of the kernel form of the hexagonal grid and their inner classes, are illustrated and compared. Because the conjugate classification is an accurate class representation of structuring elements, its real implementation is very efficient. For the operation of 0 or 1 block edge detection, a speed-up ratio of more than 6–11 compared with the same activity performed by a standard implementation of mathematical morphology, can be observed. Sample processed pictures and their timing measurements are also illustrated.
21 May 1993
TL;DR: An adaptive algorithm is developed for determining, from a given class of grayscale morphological filters, a filter which minimizes the mean square error between its output and a desired process.
Abstract: Grayscale morphology has been widely used in image processing, especially in noise removal. In this paper, we find an optimal solution for designing a grayscale morphological filter. An adaptive algorithm is developed for determining, from a given class of grayscale morphological filters, a filter which minimizes the mean square error between its output and a desired process. The adaptation using the conventional least mean square algorithm optimizes the grayscale structuring element in a given search area. The performance of noise removal is compared to another class of nonlinear filters, i.e., adaptive and nonadaptive stack-based filters.
09 Apr 1993
TL;DR: In this paper, the authors proposed a Voronoi diagram-based approach to perform morphological erosions, dilations, openings, and closings of a shape with a scaled unit disk as the structuring element.
Abstract: The Voronoi diagram of a sample set obtained from a shape boundary can be analyzed to perform morphological erosions, dilations, openings, and closings of the shape with a scaled unit disk as the structuring element. These operations collectively comprise isotropic morphology--meaning the fundamental morphological operations with a parameterized disk operator. The isotropic morphology operations are the basis of multi-scale morphological shape analysis. For instance, features obtained from a series of openings and closings by disks of varying size can be used to characterize a shape over a range of scales. In general, the isotropic morphology operations are a significant class of operations with broad potential applications. The new, Voronoi-diagram-based isotropic morphology algorithm has four significant advantages over existing algorithms: (1) the Voronoi diagram need only be computed once, and then an entire series of scale-based analyses can be performed at low incremental cost; (2) the time/space complexity of the algorithm is independent of the disk radius and depends only on the number of boundary samples; (3) the scale parameter (disk radius) can assume non-integral values; (4) the implied metric is the Euclidean metric, rather than an approximation thereof.
12 Jul 1993
TL;DR: The implementation, device requirement, and processing capability of a parallel optical computing system based on image logic algebra (ILA) and the processing capability is discussed in terms of numerical processing power.
Abstract: Implementation, device requirement, and processing capability of a parallel optical computing system based on image logicalgebra (ILA) is investigated. The proposed optical implementation requires three types of optical devices. The processingcapability of the ILA based system is discussed in terms of numerical processing power. 1. INTRODUCTION Image logic algebra (ILA)1 is a logic operation language that is particularly suitable for processing of two-dimensional (2-D) binary patterns. ILA consists of nine image operations and four operations involving neighborhood configuration patterns(NCP). A newly introduced NCP represents a particular neighboring pixel configuration for the image operations, which areextended from the structuring element of mathematical morphology. An ILA based optical parallel processing system is asingle-instruction multi-data type parallel computer. All ILA image operations are implemented optically to be executed in a parallel fashion. They take advantage of the space invariance, as well as the massive parallelism possible with opticalsystems.
01 Jan 1993
TL;DR: In this paper, the statistical properties of morphological operations (i.e., dilation, closing, clos-erosion and clos-opening) were examined using Monte Carlo simulation when applied to signals with uniform and Rayleigh distributions.
Abstract: In this paper, morphological filters [1-4] have been applied to detect flaw echoes in ultrasonic signals contaminated by grain scattering noise (i.e., clutters or speckles). In particular, the statistical properties of morphological operations (i.e., dilation, closing, clos-erosion and clos-opening) are examined using Monte Carlo simulation when applied to signals with uniform and Rayleigh distributions. The simulated results and their statistics (mean and variance) present an interpretation of the noise suppression capability of morphological filters and their biasing effects. This information has been utilized to design a suitable structuring element to enhance flaw-to-clutter ratio in ultrasonic testing. The processed experimental results (A-Scans and B-Scans) show that morphological filters can improve flaw visibility by suppressing grain scattering noise.
19 Oct 1993
TL;DR: The paper analyzes the decomposition of a morphological structuring element and concludes that the correct lower bound of decomposition is e/spl middot/lnN.
Abstract: Mathematical morphology, which is a set theoretical methodology for image analysis, can rigorously quantify many aspects of the geometrical structure of signals in a way that agrees with human intuition and perception The paper, which is based on the synthetical idea, analyzes the decomposition of a morphological structuring element For any N-point structuring element, it concludes that the correct lower bound of decomposition is e/spl middot/lnN >