The Experts below are selected from a list of 168 Experts worldwide ranked by ideXlab platform

M. Demi - One of the best experts on this subject based on the ideXlab platform.

  • Contour tracking on ultrasound sequences of vascular images
    Pattern Recognition and Image Analysis, 2008
    Co-Authors: M. Demi, Francesco Faita, Elisabetta Bianchini, V. Gemignani
    Abstract:

    Simple vascular measurements on sequences of echographic images can be used to quantify important indexes of cardiovascular risk. The measurement of the intima-media thickness and the characterization of the endothelial function are but two examples. Real-time image processing systems would be helpful to automatically track, locate, and discriminate vascular structures through image sequences. Many algorithms have been developed to accomplish this task and they are generally based on the application of a Mathematical Operator at the points of a starting contour and on an iterative procedure that brings the starting contour to the final contour. In this paper, the performances of a Mathematical Operator that exploits both temporal and spatial information are compared to those of an Operator that only exploits spatial information. The paper shows that, in general, when tracking contours on image sequences and when two or more gray-level discontinuities are present and close to each other, as in the case of arteries, both Operators should be used in sequence.

  • CIARP - Contour Tracking When Two Gray-Level Discontinuities Are Close to Each Other
    Lecture Notes in Computer Science, 2008
    Co-Authors: M. Demi, Francesco Faita, Elisabetta Bianchini, V. Gemignani
    Abstract:

    Vascular measurements are indispensable to quantify important indexes of cardiovascular risk and image processing systems are needed to automatically track the vascular structures through sequences of echographic images. Given a starting contour c n on frame f n , a contour tracking algorithm is generally based on the application of a Mathematical Operator at the points of c n and on an iterative procedure which brings such points to the respective points of the contour c n+ 1 on the subsequent frame f n+ 1 . In this paper, the performances of a Mathematical Operator which looks for similar regional gray level distributions are compared to those of an edge detection Operator. The paper shows that when two or more gray-level discontinuities are present and close to each other, as in the case of arteries, both Operators should be used sequentially.

  • MDA - A Mathematical Operator for Automatic and Real Time Analysis of Sequences of Vascular Images
    Advances in Mass Data Analysis of Images and Signals in Medicine Biotechnology Chemistry and Food Industry, 2008
    Co-Authors: M. Demi, Francesco Faita, Elisabetta Bianchini, V. Gemignani
    Abstract:

    Due to the absolute value involved, the first absolute central moment can be divided into two complementary filters: a positive deviation e p and a negative deviation e n . Both e p and e n can be used separately to highlight edges, lines, line endings, corners and junctions in images. Furthermore, the recovered edge information can be usefully combined to obtain additional information that would not be obtained by varying the parameters of the original filter. The mass center of the first absolute central moment can be also defined and an iterative localization procedure can be developed by exploiting its properties. Mathematical Operators derived from the first absolute central moment were used on a video processing device based on a DSP board and they proved to be robust and suitable for real-time implementations.

  • Online measurement of the vasodilation of peripheral arteries on ultrasound images
    Computers in Cardiology, 2005
    Co-Authors: Emanuele Bianchini, Rony Andrei, V. Gemignani, Y. Plantinga, Francesco Faita, M. Demi
    Abstract:

    The online measurement of the vasodilation of a peripheral artery is useful in many clinical applications. Moreover, ultrasound imaging is recommended because of the advantages of this technique such as non-invasivity and feasibility. However, an algorithm with a subpixel resolution is required to obtain a useful plot of the vasodilation when using ultrasound images since the temporal changes of the vascular diameter on these images are usually not greater than 1-2 pixels. The algorithm we propose in this paper is based on the first absolute central moment, a Mathematical Operator which is used as an edge detector. The performances of the algorithm are analysed both on test discontinuities and on the online analysis of the brachial artery in in-vivo studies. © 2005 IEEE.

  • The first order absolute central moment as an edge-detector in cardiovascular imaging: a comparison with two well-known edge-detectors
    Computers in Cardiology 2004, 2004
    Co-Authors: Francesco Faita, V. Gemignani, M. Giannoni, A. Benassi, E.m. Ferdeghini, M. Demi
    Abstract:

    Cardiovascular imaging usuatly requires the defection and the localization of contours. Many mathemarical Operators have been studied to improve the performances of the edge detectiun algorithms but the most frequently used Operators in literature remain the Lnplacian of Gaussian (LOG) and the gradient of Gaussian (GoG). Recently, a new Mathematical Operator, which has been obtained from the generalization uf the first absolute central momenr, has been propused. The aim ofthis paper is to compare the edge detection and localization capabilities of this Operator with those of LOG and GoC.

V. Gemignani - One of the best experts on this subject based on the ideXlab platform.

  • Contour tracking on ultrasound sequences of vascular images
    Pattern Recognition and Image Analysis, 2008
    Co-Authors: M. Demi, Francesco Faita, Elisabetta Bianchini, V. Gemignani
    Abstract:

    Simple vascular measurements on sequences of echographic images can be used to quantify important indexes of cardiovascular risk. The measurement of the intima-media thickness and the characterization of the endothelial function are but two examples. Real-time image processing systems would be helpful to automatically track, locate, and discriminate vascular structures through image sequences. Many algorithms have been developed to accomplish this task and they are generally based on the application of a Mathematical Operator at the points of a starting contour and on an iterative procedure that brings the starting contour to the final contour. In this paper, the performances of a Mathematical Operator that exploits both temporal and spatial information are compared to those of an Operator that only exploits spatial information. The paper shows that, in general, when tracking contours on image sequences and when two or more gray-level discontinuities are present and close to each other, as in the case of arteries, both Operators should be used in sequence.

  • CIARP - Contour Tracking When Two Gray-Level Discontinuities Are Close to Each Other
    Lecture Notes in Computer Science, 2008
    Co-Authors: M. Demi, Francesco Faita, Elisabetta Bianchini, V. Gemignani
    Abstract:

    Vascular measurements are indispensable to quantify important indexes of cardiovascular risk and image processing systems are needed to automatically track the vascular structures through sequences of echographic images. Given a starting contour c n on frame f n , a contour tracking algorithm is generally based on the application of a Mathematical Operator at the points of c n and on an iterative procedure which brings such points to the respective points of the contour c n+ 1 on the subsequent frame f n+ 1 . In this paper, the performances of a Mathematical Operator which looks for similar regional gray level distributions are compared to those of an edge detection Operator. The paper shows that when two or more gray-level discontinuities are present and close to each other, as in the case of arteries, both Operators should be used sequentially.

  • MDA - A Mathematical Operator for Automatic and Real Time Analysis of Sequences of Vascular Images
    Advances in Mass Data Analysis of Images and Signals in Medicine Biotechnology Chemistry and Food Industry, 2008
    Co-Authors: M. Demi, Francesco Faita, Elisabetta Bianchini, V. Gemignani
    Abstract:

    Due to the absolute value involved, the first absolute central moment can be divided into two complementary filters: a positive deviation e p and a negative deviation e n . Both e p and e n can be used separately to highlight edges, lines, line endings, corners and junctions in images. Furthermore, the recovered edge information can be usefully combined to obtain additional information that would not be obtained by varying the parameters of the original filter. The mass center of the first absolute central moment can be also defined and an iterative localization procedure can be developed by exploiting its properties. Mathematical Operators derived from the first absolute central moment were used on a video processing device based on a DSP board and they proved to be robust and suitable for real-time implementations.

  • Online measurement of the vasodilation of peripheral arteries on ultrasound images
    Computers in Cardiology, 2005
    Co-Authors: Emanuele Bianchini, Rony Andrei, V. Gemignani, Y. Plantinga, Francesco Faita, M. Demi
    Abstract:

    The online measurement of the vasodilation of a peripheral artery is useful in many clinical applications. Moreover, ultrasound imaging is recommended because of the advantages of this technique such as non-invasivity and feasibility. However, an algorithm with a subpixel resolution is required to obtain a useful plot of the vasodilation when using ultrasound images since the temporal changes of the vascular diameter on these images are usually not greater than 1-2 pixels. The algorithm we propose in this paper is based on the first absolute central moment, a Mathematical Operator which is used as an edge detector. The performances of the algorithm are analysed both on test discontinuities and on the online analysis of the brachial artery in in-vivo studies. © 2005 IEEE.

  • The first order absolute central moment as an edge-detector in cardiovascular imaging: a comparison with two well-known edge-detectors
    Computers in Cardiology 2004, 2004
    Co-Authors: Francesco Faita, V. Gemignani, M. Giannoni, A. Benassi, E.m. Ferdeghini, M. Demi
    Abstract:

    Cardiovascular imaging usuatly requires the defection and the localization of contours. Many mathemarical Operators have been studied to improve the performances of the edge detectiun algorithms but the most frequently used Operators in literature remain the Lnplacian of Gaussian (LOG) and the gradient of Gaussian (GoG). Recently, a new Mathematical Operator, which has been obtained from the generalization uf the first absolute central momenr, has been propused. The aim ofthis paper is to compare the edge detection and localization capabilities of this Operator with those of LOG and GoC.

Francesco Faita - One of the best experts on this subject based on the ideXlab platform.

  • Contour tracking on ultrasound sequences of vascular images
    Pattern Recognition and Image Analysis, 2008
    Co-Authors: M. Demi, Francesco Faita, Elisabetta Bianchini, V. Gemignani
    Abstract:

    Simple vascular measurements on sequences of echographic images can be used to quantify important indexes of cardiovascular risk. The measurement of the intima-media thickness and the characterization of the endothelial function are but two examples. Real-time image processing systems would be helpful to automatically track, locate, and discriminate vascular structures through image sequences. Many algorithms have been developed to accomplish this task and they are generally based on the application of a Mathematical Operator at the points of a starting contour and on an iterative procedure that brings the starting contour to the final contour. In this paper, the performances of a Mathematical Operator that exploits both temporal and spatial information are compared to those of an Operator that only exploits spatial information. The paper shows that, in general, when tracking contours on image sequences and when two or more gray-level discontinuities are present and close to each other, as in the case of arteries, both Operators should be used in sequence.

  • CIARP - Contour Tracking When Two Gray-Level Discontinuities Are Close to Each Other
    Lecture Notes in Computer Science, 2008
    Co-Authors: M. Demi, Francesco Faita, Elisabetta Bianchini, V. Gemignani
    Abstract:

    Vascular measurements are indispensable to quantify important indexes of cardiovascular risk and image processing systems are needed to automatically track the vascular structures through sequences of echographic images. Given a starting contour c n on frame f n , a contour tracking algorithm is generally based on the application of a Mathematical Operator at the points of c n and on an iterative procedure which brings such points to the respective points of the contour c n+ 1 on the subsequent frame f n+ 1 . In this paper, the performances of a Mathematical Operator which looks for similar regional gray level distributions are compared to those of an edge detection Operator. The paper shows that when two or more gray-level discontinuities are present and close to each other, as in the case of arteries, both Operators should be used sequentially.

  • MDA - A Mathematical Operator for Automatic and Real Time Analysis of Sequences of Vascular Images
    Advances in Mass Data Analysis of Images and Signals in Medicine Biotechnology Chemistry and Food Industry, 2008
    Co-Authors: M. Demi, Francesco Faita, Elisabetta Bianchini, V. Gemignani
    Abstract:

    Due to the absolute value involved, the first absolute central moment can be divided into two complementary filters: a positive deviation e p and a negative deviation e n . Both e p and e n can be used separately to highlight edges, lines, line endings, corners and junctions in images. Furthermore, the recovered edge information can be usefully combined to obtain additional information that would not be obtained by varying the parameters of the original filter. The mass center of the first absolute central moment can be also defined and an iterative localization procedure can be developed by exploiting its properties. Mathematical Operators derived from the first absolute central moment were used on a video processing device based on a DSP board and they proved to be robust and suitable for real-time implementations.

  • Online measurement of the vasodilation of peripheral arteries on ultrasound images
    Computers in Cardiology, 2005
    Co-Authors: Emanuele Bianchini, Rony Andrei, V. Gemignani, Y. Plantinga, Francesco Faita, M. Demi
    Abstract:

    The online measurement of the vasodilation of a peripheral artery is useful in many clinical applications. Moreover, ultrasound imaging is recommended because of the advantages of this technique such as non-invasivity and feasibility. However, an algorithm with a subpixel resolution is required to obtain a useful plot of the vasodilation when using ultrasound images since the temporal changes of the vascular diameter on these images are usually not greater than 1-2 pixels. The algorithm we propose in this paper is based on the first absolute central moment, a Mathematical Operator which is used as an edge detector. The performances of the algorithm are analysed both on test discontinuities and on the online analysis of the brachial artery in in-vivo studies. © 2005 IEEE.

  • The first order absolute central moment as an edge-detector in cardiovascular imaging: a comparison with two well-known edge-detectors
    Computers in Cardiology 2004, 2004
    Co-Authors: Francesco Faita, V. Gemignani, M. Giannoni, A. Benassi, E.m. Ferdeghini, M. Demi
    Abstract:

    Cardiovascular imaging usuatly requires the defection and the localization of contours. Many mathemarical Operators have been studied to improve the performances of the edge detectiun algorithms but the most frequently used Operators in literature remain the Lnplacian of Gaussian (LOG) and the gradient of Gaussian (GoG). Recently, a new Mathematical Operator, which has been obtained from the generalization uf the first absolute central momenr, has been propused. The aim ofthis paper is to compare the edge detection and localization capabilities of this Operator with those of LOG and GoC.

Peter Hering - One of the best experts on this subject based on the ideXlab platform.

Nicolo Speciale - One of the best experts on this subject based on the ideXlab platform.

  • Fast Operators for arbitrary warping maps
    2008 IEEE International Symposium on Circuits and Systems, 2008
    Co-Authors: Salvatore Caporale, Luca De Marchi, Nicolo Speciale
    Abstract:

    In this work we describe a Mathematical Operator for the fast calculation of frequency warping. Such invertible transformation can be used to reshape the tiling of time- frequency analysis in a flexible way. In our approach the warping is computed by splitting the transformation Operator in two additive terms: the first term represents its Nonuniform Fourier Transform approximation while the second term is imposed for aliasing suppression. The first transformation is known to be analytically characterized and rapidly computable by interpolation approaches. An analytical characterization of the second transformation Operator is proposed for arbitrary shaped non-smooth warping maps commonly used for signal processing applications.

  • ISCAS - Fast Operators for arbitrary warping maps
    2008 IEEE International Symposium on Circuits and Systems, 2008
    Co-Authors: Salvatore Caporale, Luca De Marchi, Nicolo Speciale
    Abstract:

    In this work we describe a Mathematical Operator for the fast calculation of frequency warping. Such invertible transformation can be used to reshape the tiling of time- frequency analysis in a flexible way. In our approach the warping is computed by splitting the transformation Operator in two additive terms: the first term represents its Nonuniform Fourier Transform approximation while the second term is imposed for aliasing suppression. The first transformation is known to be analytically characterized and rapidly computable by interpolation approaches. An analytical characterization of the second transformation Operator is proposed for arbitrary shaped non-smooth warping maps commonly used for signal processing applications.