The Experts below are selected from a list of 11697 Experts worldwide ranked by ideXlab platform

F G Hoppin - One of the best experts on this subject based on the ideXlab platform.

  • semi automated measurement of true Chord Length distributions and moments by video microscopy and image analysis
    Journal of Microscopy, 1994
    Co-Authors: E H Oldmixon, James P Butler, F G Hoppin
    Abstract:

    Summary The distribution of the Lengths of airspace Chords in pulmonary parenchyma characterizes many architectural features of the alveoli and alveolar ducts. Laborious to obtain manually, the distributions and density functions may be acquired semi-automatically by video microscopy, digitization and image processing. The accuracy of the estimation is influenced by the microscopical methods and also by the techniques used (i) to convert the digitized grey-scale picture to a two-valued image, (ii) to collect the Chord Lengths and (iii) to compensate for finite field widths. The last problem arises because some Chords are completely visible within a field while others are only partially seen, since one of the two air-tissue boundaries lies outside the field of view. This error systematically biases the observed distribution. This paper contains solutions to hardware, software and analytic problems encountered while developing the capability to measure airspace Chord Length density functions semi-automatically. Formulas for estimating the true Chord Length density function from samples of observed Chord Lengths are presented. Also given are formulas for the estimation of the first and second moments of the true Chord Length distribution from the means of observed Chord Lengths. These techniques of image preparation and analysis should be suitable for characterizing particle, grain or cell size distributions, especially where many profiles fall partially outside the field of view.

  • Semi‐automated measurement of true Chord Length distributions and moments by video microscopy and image analysis
    Journal of Microscopy, 1994
    Co-Authors: E H Oldmixon, James P Butler, F G Hoppin
    Abstract:

    Summary The distribution of the Lengths of airspace Chords in pulmonary parenchyma characterizes many architectural features of the alveoli and alveolar ducts. Laborious to obtain manually, the distributions and density functions may be acquired semi-automatically by video microscopy, digitization and image processing. The accuracy of the estimation is influenced by the microscopical methods and also by the techniques used (i) to convert the digitized grey-scale picture to a two-valued image, (ii) to collect the Chord Lengths and (iii) to compensate for finite field widths. The last problem arises because some Chords are completely visible within a field while others are only partially seen, since one of the two air-tissue boundaries lies outside the field of view. This error systematically biases the observed distribution. This paper contains solutions to hardware, software and analytic problems encountered while developing the capability to measure airspace Chord Length density functions semi-automatically. Formulas for estimating the true Chord Length density function from samples of observed Chord Lengths are presented. Also given are formulas for the estimation of the first and second moments of the true Chord Length distribution from the means of observed Chord Lengths. These techniques of image preparation and analysis should be suitable for characterizing particle, grain or cell size distributions, especially where many profiles fall partially outside the field of view.

Bin Wang - One of the best experts on this subject based on the ideXlab platform.

  • Shape retrieval using statistical Chord-Length features
    Lecture Notes in Computer Science, 2020
    Co-Authors: Bin Wang
    Abstract:

    A novel shape description method, statistical Chord-Length features (SCLF), is proposed for shape retrieval. SCLF first describes the contour of a 2D shape using k/2 one-dimensional Chord-Length functions derived from partitioning the contour into k arcs of the same Length, where k is the parameter of SCLF. The means and variances of all the Chord-Length functions are then calculated and a k dimensional feature vector is generated as a shape descriptor. Two experiments are conducted and the results show that SCLF achieves higher retrieval performance than traditional description methods such as geometric moment invariants and Fourier descriptors.

  • Shape matching using Chord-Length function
    Lecture Notes in Computer Science, 2020
    Co-Authors: Bin Wang
    Abstract:

    A novel shape descriptor, Chord Length function (CLF) which can be obtained by equal arc Length partitions of a contour, is proposed. The difference of two shapes is measured by the distance between their corresponding CLF. The proposed CLF is invariant to rotation, scaling and translation. It is robust to noise and simple to compute. Experimental results indicate that CLF is an effective shape descriptor.

  • PSIVT - Shape retrieval using statistical Chord-Length features
    Advances in Image and Video Technology, 2006
    Co-Authors: Bin Wang
    Abstract:

    A novel shape description method, statistical Chord-Length features (SCLF), is proposed for shape retrieval. SCLF first describes the contour of a 2D shape using k/2 one-dimensional Chord-Length functions derived from partitioning the contour into k arcs of the same Length, where k is the parameter of SCLF. The means and variances of all the Chord-Length functions are then calculated and a k dimensional feature vector is generated as a shape descriptor. Two experiments are conducted and the results show that SCLF achieves higher retrieval performance than traditional description methods such as geometric moment invariants and Fourier descriptors.

  • IDEAL - Shape matching using Chord-Length function
    Intelligent Data Engineering and Automated Learning – IDEAL 2006, 2006
    Co-Authors: Bin Wang
    Abstract:

    A novel shape descriptor, Chord Length function (CLF) which can be obtained by equal arc Length partitions of a contour, is proposed. The difference of two shapes is measured by the distance between their corresponding CLF. The proposed CLF is invariant to rotation, scaling and translation. It is robust to noise and simple to compute. Experimental results indicate that CLF is an effective shape descriptor.

E H Oldmixon - One of the best experts on this subject based on the ideXlab platform.

  • semi automated measurement of true Chord Length distributions and moments by video microscopy and image analysis
    Journal of Microscopy, 1994
    Co-Authors: E H Oldmixon, James P Butler, F G Hoppin
    Abstract:

    Summary The distribution of the Lengths of airspace Chords in pulmonary parenchyma characterizes many architectural features of the alveoli and alveolar ducts. Laborious to obtain manually, the distributions and density functions may be acquired semi-automatically by video microscopy, digitization and image processing. The accuracy of the estimation is influenced by the microscopical methods and also by the techniques used (i) to convert the digitized grey-scale picture to a two-valued image, (ii) to collect the Chord Lengths and (iii) to compensate for finite field widths. The last problem arises because some Chords are completely visible within a field while others are only partially seen, since one of the two air-tissue boundaries lies outside the field of view. This error systematically biases the observed distribution. This paper contains solutions to hardware, software and analytic problems encountered while developing the capability to measure airspace Chord Length density functions semi-automatically. Formulas for estimating the true Chord Length density function from samples of observed Chord Lengths are presented. Also given are formulas for the estimation of the first and second moments of the true Chord Length distribution from the means of observed Chord Lengths. These techniques of image preparation and analysis should be suitable for characterizing particle, grain or cell size distributions, especially where many profiles fall partially outside the field of view.

  • Semi‐automated measurement of true Chord Length distributions and moments by video microscopy and image analysis
    Journal of Microscopy, 1994
    Co-Authors: E H Oldmixon, James P Butler, F G Hoppin
    Abstract:

    Summary The distribution of the Lengths of airspace Chords in pulmonary parenchyma characterizes many architectural features of the alveoli and alveolar ducts. Laborious to obtain manually, the distributions and density functions may be acquired semi-automatically by video microscopy, digitization and image processing. The accuracy of the estimation is influenced by the microscopical methods and also by the techniques used (i) to convert the digitized grey-scale picture to a two-valued image, (ii) to collect the Chord Lengths and (iii) to compensate for finite field widths. The last problem arises because some Chords are completely visible within a field while others are only partially seen, since one of the two air-tissue boundaries lies outside the field of view. This error systematically biases the observed distribution. This paper contains solutions to hardware, software and analytic problems encountered while developing the capability to measure airspace Chord Length density functions semi-automatically. Formulas for estimating the true Chord Length density function from samples of observed Chord Lengths are presented. Also given are formulas for the estimation of the first and second moments of the true Chord Length distribution from the means of observed Chord Lengths. These techniques of image preparation and analysis should be suitable for characterizing particle, grain or cell size distributions, especially where many profiles fall partially outside the field of view.

Wilfried Gille - One of the best experts on this subject based on the ideXlab platform.

  • Chord Length distribution of pentagonal and hexagonal rods relation to small angle scattering
    Journal of Applied Crystallography, 2009
    Co-Authors: Wilfried Gille, Narine G Aharonyan, Hrachya S Harutyunyan
    Abstract:

    Based on explicit formulas of Chord Length density functions (CLDs) for a regular pentagon and a hexagon, the CLDs of infinitely long regular homogeneous pentagonal/hexagonal cylinders are discussed. Characteristic properties of the small-angle scattering of these cylinders are studied.

  • Chord Length Distributions of the Hemisphere
    Journal of Mathematics and Statistics, 2005
    Co-Authors: Wilfried Gille
    Abstract:

    The distribution laws for two types of isotropic uniform random Chords of the hemisphere, cap-Chords and basic-Chords, are investigated separately. From both distribution densities, the Chord Length distribution density of the whole hemisphere is derived.

  • properties of Chord Length distributions of nonconvex bodies
    Journal of Mathematical Physics, 2003
    Co-Authors: Alain Mazzolo, Benoit Roesslinger, Wilfried Gille
    Abstract:

    Cauchy’s formula which relates the mean Chord Length (isotropic uniform random Chords) of a convex body in Rn with its volume and surface is extended to the case of nonconvex bodies in the framework of integral geometry. This allows us to generalize the extended Cauchy’s formula recently discovered by Blanco and Fournier [Europhys. Lett. 61 (2), 168 (2003)], in the field of diffusive random walks, to nonconvex bodies. Monte Carlo simulations illustrate these points in R2 and in R3.

  • Chord Length distributions of infinitely long geometric figures
    Powder Technology, 2002
    Co-Authors: Wilfried Gille
    Abstract:

    Abstract A transformation method for establishing Chord Length distributions for infinitely long “rods” of various cross-sections is presented. Here, the information on the two-dimensional cross section of the object is used to define the Chord Length distribution of the three-dimensional “rod”. Let P(r) be the Chord Length distribution density of a plane convex two-dimensional geometric figure X, for example of a circle. Let Y be the corresponding three-dimensional infinitely long geometric figure with the same cross-section X, for example, a right infinitely long circular cylinder. Then, the Chord Length distribution density A(r) of figure Y is completely defined in terms of P(r). An integral transform, which solves the problem for each convex X, Y, is evaluated and tested. This is useful for an effective characterization of long-stretched microparticles in micropowders via their Chord Length distribution. The spectrum of available A(r) functions is increased for a large class of geometric figures. For example, the new transformation allows the evaluation of A(r,a,b) of an infinitely long elliptical cylinder with semiaxes a, b based on P(r,a,b) of an ellipse X.

  • the Chord Length distribution of a triangular rod
    Computational Materials Science, 2001
    Co-Authors: Wilfried Gille
    Abstract:

    Abstract A triangular rod (edge Length of the basic triangle is a) is considered. Analytic expressions of the Chord Length distribution density A(l,a) and other structure functions of small-angle scattering are calculated. Applications of A(l,a) in the field of SAS are discussed. The three-dimensional correlation function and the asymptotic behaviour of the SAS intensity I(h) are analyzed. Here, the Kirste–Porod term is missing which correlates with the fact that parallel interfaces do not exist.

Kumar Patchigolla - One of the best experts on this subject based on the ideXlab platform.

  • obtaining particle size distribution from Chord Length measurements
    Particle & Particle Systems Characterization, 2006
    Co-Authors: Mingzhong Li, Derek Wilkinson, Kumar Patchigolla
    Abstract:

    The Lasentec focused-beam reflectance measurement (FBRM) is becoming a more popular technique to measure particle size on-line in different applications. The FBRM uses a focused beam of laser light that scans across particles passing in front of the probe window to measure a Chord Length distribution (CLD). Compared with CLD information, the particle size distribution (PSD) is more useful because it is directly related to product quality and process productivity. However, it is not straightforward to convert a measured CLD into its corresponding PSD accurately due to the lack of a theoretical analysis for non-spherical particle systems. In this paper, firstly a general model to translate a PSD into its corresponding CLD is given for different shapes including spherical, ellipsoidal and more general non-spherical particles. Then an iterative inversion method is developed to obtain the PSD from a measured CLD. Finally, effectiveness of the proposed PSD-CLD model and iterative inversion method has been extensively validated by experiments.

  • determination of non spherical particle size distribution from Chord Length measurements part 2 experimental validation
    Chemical Engineering Science, 2005
    Co-Authors: Mingzhong Li, Derek Wilkinson, Kumar Patchigolla
    Abstract:

    Abstract In this paper, the theory on the translation of a measured Chord Length distribution (CLD) into its particle size distribution (PSD), which was developed in the first part of this study [Li and Wilkinson, 2005. Determination of non-spherical particle size distribution from Chord Length measurements. Part 1: theoretical analysis. Chemical Engineering Science 60, 3251–3265], has been validated using experimental results. CLDs were measured using the Lasentec focused beam reflectance measurement (FBRM) with three different materials, spherical ceramic beads and non-spherical plasma aluminium and zinc dust particles. Meanwhile, the particle shape and PSD of each material were also investigated by image analysis (IA). Comparison of the retrieved PSDs with the measured PSDs by IA shows that the PSD can be retrieved from a measured CLD successfully using the proposed iterative nonnegative least squares (NNLS) method based on the PSD–CLD model.