The Experts below are selected from a list of 474819 Experts worldwide ranked by ideXlab platform

Jing Zhang - One of the best experts on this subject based on the ideXlab platform.

  • a new calibration Model of camera lens distortion
    2008
    Co-Authors: Jianhua Wang, Jing Zhang
    Abstract:

    Lens distortion is one of the main factors affecting camera calibration. In this paper, a new Model of camera lens distortion is presented, according to which lens distortion is governed by the coefficients of radial distortion and a transform from ideal image plane to real sensor array plane. The transform is determined by two angular parameters describing the pose of the real sensor array plane with respect to the ideal image plane and two linear parameters locating the real sensor array with respect to the optical axis. Experiments show that the new Model has about the same correcting effect upon lens distortion as the Conventional Model including all the radial distortion, decentering distortion and prism distortion. Compared with the Conventional Model, the new Model has fewer parameters to be calibrated and more explicit physical meaning.

  • a new calibration Model of camera lens distortion
    2008
    Co-Authors: Jianhua Wang, Jing Zhang
    Abstract:

    Lens distortion is one of the main factors affecting camera calibration. In this paper, a new Model of camera lens distortion is presented, according to which lens distortion is governed by the coefficients of radial distortion and a transform from ideal image plane to real sensor array plane. The transform is determined by two angular parameters describing the pose of the real sensor array plane with respect to the ideal image plane and two linear parameters locating the real sensor array with respect to the optical axis. Experiments show that the new Model has about the same correcting effect upon lens distortion as the Conventional Model including all the radial distortion, decentering distortion and prism distortion. Compared with the Conventional Model, the new Model has fewer parameters to be calibrated and more explicit physical meaning.

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

  • a new calibration Model of camera lens distortion
    2008
    Co-Authors: Jianhua Wang, Jing Zhang
    Abstract:

    Lens distortion is one of the main factors affecting camera calibration. In this paper, a new Model of camera lens distortion is presented, according to which lens distortion is governed by the coefficients of radial distortion and a transform from ideal image plane to real sensor array plane. The transform is determined by two angular parameters describing the pose of the real sensor array plane with respect to the ideal image plane and two linear parameters locating the real sensor array with respect to the optical axis. Experiments show that the new Model has about the same correcting effect upon lens distortion as the Conventional Model including all the radial distortion, decentering distortion and prism distortion. Compared with the Conventional Model, the new Model has fewer parameters to be calibrated and more explicit physical meaning.

  • a new calibration Model of camera lens distortion
    2008
    Co-Authors: Jianhua Wang, Jing Zhang
    Abstract:

    Lens distortion is one of the main factors affecting camera calibration. In this paper, a new Model of camera lens distortion is presented, according to which lens distortion is governed by the coefficients of radial distortion and a transform from ideal image plane to real sensor array plane. The transform is determined by two angular parameters describing the pose of the real sensor array plane with respect to the ideal image plane and two linear parameters locating the real sensor array with respect to the optical axis. Experiments show that the new Model has about the same correcting effect upon lens distortion as the Conventional Model including all the radial distortion, decentering distortion and prism distortion. Compared with the Conventional Model, the new Model has fewer parameters to be calibrated and more explicit physical meaning.

Yuko Osana - One of the best experts on this subject based on the ideXlab platform.

  • fast kohonen feature map associative memory using area representation for sequential analog patterns
    2010
    Co-Authors: Hiroki Midorikawa, Yuko Osana
    Abstract:

    In this paper, we propose a Fast Kohonen Feature Map Associative Memory with Area Representation for Sequential Analog Patterns (FKFMAM-AR-SAP). This Model is based on the Conventional Improved Kohonen Feature Map Associative Memory with Area Representation for Sequential Analog Patterns (IKFMAM-AR-SAP). The proposed Model can realize the one-to-many associations even when the first patterns are same in the plural sequential patterns. And, it has enough robustness for noisy input and damaged neurons. Moreover, the learning speed of the proposed Model is faster than that of the Conventional Model. We carried out a series of computer experiments and confirmed the effectiveness of the proposed Model.

  • improved kohonen feature map associative memory with area representation for sequential analog patterns
    2009
    Co-Authors: Tomonori Shirotori, Yuko Osana
    Abstract:

    In this paper, we propose an improved Kohonen feature map associative memory with area representation for sequential analog patterns. This Model is based on the Conventional Kohonen feature map associative memory with area representation for sequential analog patterns. The proposed Model has enough robustness for noisy input and damaged neurons. Moreover, the learning speed of the proposed Model is faster than that of the Conventional Model. We carried out a series of computer experiments and confirmed the effectiveness of the proposed Model.

O Reimer - One of the best experts on this subject based on the ideXlab platform.

  • diffuse galactic continuum gamma rays a Model compatible with egret data and cosmic ray measurements
    2004
    Co-Authors: A W Strong, I V Moskalenko, O Reimer
    Abstract:

    We present a study of the compatibility of some current Models of the diffuse Galactic continuum � -rays with EGRET data. A set of regions sampling the whole sky is chosen to provide a comprehensive range of tests. The range of EGRET data used is extended to 100 GeV. The Models are computed with our GALPROP cosmic-ray propagation and � -ray production code. We confirm that the ‘‘Conventional Model’’ based on the locally observed electron and nucleon spectra is inadequate, for all sky regions. A Conventional Model plus hard sources in the inner Galaxy is also inadequate, since this cannot explain the GeVexcess away from the Galactic plane. Models with a hard electron injection spectrum are inconsistent with the local spectrum even considering the expected fluctuations; they are also inconsistent with the EGRET data above 10 GeV. We present a new Model that fits the spectrum in all sky regions adequately. Secondary antiproton data were used to fix the Galactic average proton spectrum, while the electron spectrum is adjusted using the spectrum of diffuse emission itself. The derived electron and proton spectra are compatible with those measured locally considering fluctuations due to energy losses, propagation, or possibly details of Galactic structure. This Model requires a much less dramatic variation in the electron spectrum than Models with a hard electron injection spectrum, and moreover it fits the � -ray spectrum better and to the highest EGRET energies. It gives a good representation of the latitude distribution of the � -ray emission from the plane to the poles, and of the longitude distribution. We show that secondary positrons and electrons make an essential contribution to Galactic diffuse � -ray emission. Subject heading gs: cosmic rays — diffusion — Galaxy: general — gamma rays: observations — gamma rays: theory — ISM: general

  • diffuse galactic continuum gamma rays a Model compatible with egret data and cosmic ray measurements
    2004
    Co-Authors: A W Strong, I V Moskalenko, O Reimer
    Abstract:

    We present a study of the compatibility of some current Models of the diffuse Galactic continuum gamma rays with EGRET data. A set of regions sampling the whole sky is chosen to provide a comprehensive range of tests. The range of EGRET data used is extended to 100 GeV. The Models are computed with our GALPROP cosmic-ray propagation and gamma-ray production code. We confirm that the "Conventional Model" based on the locally observed electron and nucleon spectra is inadequate, for all sky regions. A Conventional Model plus hard sources in the inner Galaxy is also inadequate, since this cannot explain the GeV excess away from the Galactic plane. Models with a hard electron injection spectrum are inconsistent with the local spectrum even considering the expected fluctuations; they are also inconsistent with the EGRET data above 10 GeV. We present a new Model which fits the spectrum in all sky regions adequately. Secondary antiproton data were used to fix the Galactic average proton spectrum, while the electron spectrum is adjusted using the spectrum of diffuse emission itself. The derived electron and proton spectra are compatible with those measured locally considering fluctuations due to energy losses, propagation, or possibly details of Galactic structure. This Model requires a much less dramatic variation in the electron spectrum than Models with a hard electron injection spectrum, and moreover it fits the gamma-ray spectrum better and to the highest EGRET energies. It gives a good representation of the latitude distribution of the gamma-ray emission from the plane to the poles, and of the longitude distribution. We show that secondary positrons and electrons make an essential contribution to Galactic diffuse gamma-ray emission.

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

  • diffuse galactic continuum gamma rays a Model compatible with egret data and cosmic ray measurements
    2004
    Co-Authors: A W Strong, I V Moskalenko, O Reimer
    Abstract:

    We present a study of the compatibility of some current Models of the diffuse Galactic continuum � -rays with EGRET data. A set of regions sampling the whole sky is chosen to provide a comprehensive range of tests. The range of EGRET data used is extended to 100 GeV. The Models are computed with our GALPROP cosmic-ray propagation and � -ray production code. We confirm that the ‘‘Conventional Model’’ based on the locally observed electron and nucleon spectra is inadequate, for all sky regions. A Conventional Model plus hard sources in the inner Galaxy is also inadequate, since this cannot explain the GeVexcess away from the Galactic plane. Models with a hard electron injection spectrum are inconsistent with the local spectrum even considering the expected fluctuations; they are also inconsistent with the EGRET data above 10 GeV. We present a new Model that fits the spectrum in all sky regions adequately. Secondary antiproton data were used to fix the Galactic average proton spectrum, while the electron spectrum is adjusted using the spectrum of diffuse emission itself. The derived electron and proton spectra are compatible with those measured locally considering fluctuations due to energy losses, propagation, or possibly details of Galactic structure. This Model requires a much less dramatic variation in the electron spectrum than Models with a hard electron injection spectrum, and moreover it fits the � -ray spectrum better and to the highest EGRET energies. It gives a good representation of the latitude distribution of the � -ray emission from the plane to the poles, and of the longitude distribution. We show that secondary positrons and electrons make an essential contribution to Galactic diffuse � -ray emission. Subject heading gs: cosmic rays — diffusion — Galaxy: general — gamma rays: observations — gamma rays: theory — ISM: general

  • diffuse galactic continuum gamma rays a Model compatible with egret data and cosmic ray measurements
    2004
    Co-Authors: A W Strong, I V Moskalenko, O Reimer
    Abstract:

    We present a study of the compatibility of some current Models of the diffuse Galactic continuum gamma rays with EGRET data. A set of regions sampling the whole sky is chosen to provide a comprehensive range of tests. The range of EGRET data used is extended to 100 GeV. The Models are computed with our GALPROP cosmic-ray propagation and gamma-ray production code. We confirm that the "Conventional Model" based on the locally observed electron and nucleon spectra is inadequate, for all sky regions. A Conventional Model plus hard sources in the inner Galaxy is also inadequate, since this cannot explain the GeV excess away from the Galactic plane. Models with a hard electron injection spectrum are inconsistent with the local spectrum even considering the expected fluctuations; they are also inconsistent with the EGRET data above 10 GeV. We present a new Model which fits the spectrum in all sky regions adequately. Secondary antiproton data were used to fix the Galactic average proton spectrum, while the electron spectrum is adjusted using the spectrum of diffuse emission itself. The derived electron and proton spectra are compatible with those measured locally considering fluctuations due to energy losses, propagation, or possibly details of Galactic structure. This Model requires a much less dramatic variation in the electron spectrum than Models with a hard electron injection spectrum, and moreover it fits the gamma-ray spectrum better and to the highest EGRET energies. It gives a good representation of the latitude distribution of the gamma-ray emission from the plane to the poles, and of the longitude distribution. We show that secondary positrons and electrons make an essential contribution to Galactic diffuse gamma-ray emission.