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Takashi Komatsu - One of the best experts on this subject based on the ideXlab platform.

  • Selective image‐sharpness enhancement by coupled nonlinear reaction‐Diffusion Time‐evolution equations and its application to suppression of breathing distortions in moving pictures
    Electronics and Communications in Japan Part Iii-fundamental Electronic Science, 2020
    Co-Authors: Takahiro Saito, Jun Satsumabayashi, Takashi Komatsu
    Abstract:

    The authors describe a technique for selectively sharpening only edges that were blurred due to various causes without making interference factors such as random noise more conspicuous. The selective sharpening technique described in this paper is implemented as an iterative updating nonlinear algorithm obtained by discretizing a type of nonlinear reaction-Diffusion Time-evolution equations. The update terms of this algorithm consist of a quadratic nonlinear smoothing term, reaction term, and overshooting term. By performing quantitative evaluation experiments, the authors showed that the proposed technique has significantly better selective sharpness enhancement capabilities than existing sharpness enhancement techniques such as the peaking method. In addition, the authors introduced a processing parameter adaptive control method in the proposed technique and applied it to the suppression of breathing distortions in video sequences. Breathing distortions, which are video sequence distortions that often appear in old films, are Time-varying blurring distortions that occur due to temporal variations of the focus. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(5): 33–47, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10086

  • EUSIPCO - Selective image-sharpness enhancement by coupled nonlinear reaction-Diffusion Time-evolution and its practical application
    2002
    Co-Authors: Takahiro Saito, Jun Satsumabayashi, Kentarou Yashiro, Takashi Komatsu
    Abstract:

    This paper presents a method for selective sharpness enhancement that can sharpen only degraded edges blurred by several causes without increasing the visibility of nuisance factors such as random noise. The method is based on the coupled nonlinear reaction-Diffusion Time-evolution equipped with a second-order nonlinear smoothing term, a reaction term and an overshooting term. The quantitative performance evaluations demonstrate that the method sharpens blurred edges selectively much better than the existing sharpness enhancement methods such as the peaking method and the Volterra filter method. Moreover, this paper applies the method to the real problem of the breathing-distortion removal.

  • VCIP - Selective sharpness enhancement of corrupted old film sequences by coupled nonlinear reaction-Diffusion Time-evolution
    Visual Communications and Image Processing 2002, 2002
    Co-Authors: Takahiro Saito, Jun Satsumabayashi, Kentarou Yashiro, Takashi Komatsu
    Abstract:

    In old movie film, most of sharp brightness transitions have been blurred, and film materials are often corrupted by several distortions such as blotches. To restore original edge sharpness without augmenting visibility of such distortions, first we characterize such distortion areas, repair them and then sharpen only blurred edges selectively. This paper presents a locally-adaptive sharpening method based on the coupled nonlinear reaction-Diffusion Time-evolution equipped with a second-order nonlinear smoothing term, a reaction term and an overshooting term. The overshooting term adds an overshoot only to the blurred edges. The coupled nonlinear reaction-Diffusion method utilizes information about local image contents and the characterized film distortions, to control the degree of the second-order smoothing and the magnitude of the overshoot to be added. Our method sharpens blurred edges selectively much better than our previously presented adaptive peaking method. Our method, of course, is applicable to sharpness enhancement of general blurred images.

  • Selective image-sharpness enhancement by coupled nonlinear reaction-Diffusion Time-evolution and its practical application
    2002 11th European Signal Processing Conference, 2002
    Co-Authors: Takahiro Saito, Jun Satsumabayashi, Kentarou Yashiro, Takashi Komatsu
    Abstract:

    This paper presents a method for selective sharpness enhancement that can sharpen only degraded edges blurred by several causes without increasing the visibility of nuisance factors such as random noise. The method is based on the coupled nonlinear reaction-Diffusion Time-evolution equipped with a second-order nonlinear smoothing term, a reaction term and an overshooting term. The quantitative performance evaluations demonstrate that the method sharpens blurred edges selectively much better than the existing sharpness enhancement methods such as the peaking method and the Volterra filter method. Moreover, this paper applies the method to the real problem of the breathing-distortion removal.

Takahiro Saito - One of the best experts on this subject based on the ideXlab platform.

  • Selective image‐sharpness enhancement by coupled nonlinear reaction‐Diffusion Time‐evolution equations and its application to suppression of breathing distortions in moving pictures
    Electronics and Communications in Japan Part Iii-fundamental Electronic Science, 2020
    Co-Authors: Takahiro Saito, Jun Satsumabayashi, Takashi Komatsu
    Abstract:

    The authors describe a technique for selectively sharpening only edges that were blurred due to various causes without making interference factors such as random noise more conspicuous. The selective sharpening technique described in this paper is implemented as an iterative updating nonlinear algorithm obtained by discretizing a type of nonlinear reaction-Diffusion Time-evolution equations. The update terms of this algorithm consist of a quadratic nonlinear smoothing term, reaction term, and overshooting term. By performing quantitative evaluation experiments, the authors showed that the proposed technique has significantly better selective sharpness enhancement capabilities than existing sharpness enhancement techniques such as the peaking method. In addition, the authors introduced a processing parameter adaptive control method in the proposed technique and applied it to the suppression of breathing distortions in video sequences. Breathing distortions, which are video sequence distortions that often appear in old films, are Time-varying blurring distortions that occur due to temporal variations of the focus. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(5): 33–47, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10086

  • EUSIPCO - Selective image-sharpness enhancement by coupled nonlinear reaction-Diffusion Time-evolution and its practical application
    2002
    Co-Authors: Takahiro Saito, Jun Satsumabayashi, Kentarou Yashiro, Takashi Komatsu
    Abstract:

    This paper presents a method for selective sharpness enhancement that can sharpen only degraded edges blurred by several causes without increasing the visibility of nuisance factors such as random noise. The method is based on the coupled nonlinear reaction-Diffusion Time-evolution equipped with a second-order nonlinear smoothing term, a reaction term and an overshooting term. The quantitative performance evaluations demonstrate that the method sharpens blurred edges selectively much better than the existing sharpness enhancement methods such as the peaking method and the Volterra filter method. Moreover, this paper applies the method to the real problem of the breathing-distortion removal.

  • VCIP - Selective sharpness enhancement of corrupted old film sequences by coupled nonlinear reaction-Diffusion Time-evolution
    Visual Communications and Image Processing 2002, 2002
    Co-Authors: Takahiro Saito, Jun Satsumabayashi, Kentarou Yashiro, Takashi Komatsu
    Abstract:

    In old movie film, most of sharp brightness transitions have been blurred, and film materials are often corrupted by several distortions such as blotches. To restore original edge sharpness without augmenting visibility of such distortions, first we characterize such distortion areas, repair them and then sharpen only blurred edges selectively. This paper presents a locally-adaptive sharpening method based on the coupled nonlinear reaction-Diffusion Time-evolution equipped with a second-order nonlinear smoothing term, a reaction term and an overshooting term. The overshooting term adds an overshoot only to the blurred edges. The coupled nonlinear reaction-Diffusion method utilizes information about local image contents and the characterized film distortions, to control the degree of the second-order smoothing and the magnitude of the overshoot to be added. Our method sharpens blurred edges selectively much better than our previously presented adaptive peaking method. Our method, of course, is applicable to sharpness enhancement of general blurred images.

  • Selective image-sharpness enhancement by coupled nonlinear reaction-Diffusion Time-evolution and its practical application
    2002 11th European Signal Processing Conference, 2002
    Co-Authors: Takahiro Saito, Jun Satsumabayashi, Kentarou Yashiro, Takashi Komatsu
    Abstract:

    This paper presents a method for selective sharpness enhancement that can sharpen only degraded edges blurred by several causes without increasing the visibility of nuisance factors such as random noise. The method is based on the coupled nonlinear reaction-Diffusion Time-evolution equipped with a second-order nonlinear smoothing term, a reaction term and an overshooting term. The quantitative performance evaluations demonstrate that the method sharpens blurred edges selectively much better than the existing sharpness enhancement methods such as the peaking method and the Volterra filter method. Moreover, this paper applies the method to the real problem of the breathing-distortion removal.

Thomas K Pilgram - One of the best experts on this subject based on the ideXlab platform.

  • effects of Diffusion Time on short range hyperpolarized 3he diffusivity measurements in emphysema
    Journal of Magnetic Resonance Imaging, 2009
    Co-Authors: David S Gierada, Jason C Woods, Andrew J Bierhals, Seth T Bartel, Jon H Ritter, Cliff Khuat Chye Choong, Cheng Hong, Thomas K Pilgram
    Abstract:

    Purpose: To characterize the effect of Diffusion Time on short-range hyperpolarized 3He MR Diffusion measurements across a wide range of emphysema severity. Materials and Methods: 3He Diffusion MR imaging was performed on 19 lungs or lobes resected from 18 subjects with varying degrees of emphysema using 3 Diffusion Times (1.6 msec, 5 msec, and 10 msec) at constant b value. Emphysema severity was quantified as the mean apparent Diffusion coefficient (ADC) and as the percentage of pixels with ADC higher than multiple thresholds from 0.30-0.55 cm2/sec (ADC index). Quantitative histology (mean linear intercept) was obtained in 10 of the lung specimens from 10 of the subjects. Results: The mean ADCs with Diffusion Times of 1.6, 5.0, and 10.0 msec were 0.46, 0.40, and 0.37 cm2/sec, respectively (P <0.0001, ANOVA). There was no relationship between the ADC magnitude and the effect of Diffusion Time on ADC values. Mean linear intercept correlated with ADC (r=0.91-0.94, P<0.001) and ADC index (r=0.78-0.92, P<0.01) at all Diffusion Times.

  • Effects of Diffusion Time on short‐range hyperpolarized 3He diffusivity measurements in emphysema
    Journal of Magnetic Resonance Imaging, 2009
    Co-Authors: David S Gierada, Jason C Woods, Andrew J Bierhals, Seth T Bartel, Jon H Ritter, Cliff Khuat Chye Choong, Cheng Hong, Thomas K Pilgram, Yulin V. Chang
    Abstract:

    Purpose: To characterize the effect of Diffusion Time on short-range hyperpolarized 3He MR Diffusion measurements across a wide range of emphysema severity. Materials and Methods: 3He Diffusion MR imaging was performed on 19 lungs or lobes resected from 18 subjects with varying degrees of emphysema using 3 Diffusion Times (1.6 msec, 5 msec, and 10 msec) at constant b value. Emphysema severity was quantified as the mean apparent Diffusion coefficient (ADC) and as the percentage of pixels with ADC higher than multiple thresholds from 0.30-0.55 cm2/sec (ADC index). Quantitative histology (mean linear intercept) was obtained in 10 of the lung specimens from 10 of the subjects. Results: The mean ADCs with Diffusion Times of 1.6, 5.0, and 10.0 msec were 0.46, 0.40, and 0.37 cm2/sec, respectively (P

Cliff Khuat Chye Choong - One of the best experts on this subject based on the ideXlab platform.

  • effects of Diffusion Time on short range hyperpolarized 3he diffusivity measurements in emphysema
    Journal of Magnetic Resonance Imaging, 2009
    Co-Authors: David S Gierada, Jason C Woods, Andrew J Bierhals, Seth T Bartel, Jon H Ritter, Cliff Khuat Chye Choong, Cheng Hong, Thomas K Pilgram
    Abstract:

    Purpose: To characterize the effect of Diffusion Time on short-range hyperpolarized 3He MR Diffusion measurements across a wide range of emphysema severity. Materials and Methods: 3He Diffusion MR imaging was performed on 19 lungs or lobes resected from 18 subjects with varying degrees of emphysema using 3 Diffusion Times (1.6 msec, 5 msec, and 10 msec) at constant b value. Emphysema severity was quantified as the mean apparent Diffusion coefficient (ADC) and as the percentage of pixels with ADC higher than multiple thresholds from 0.30-0.55 cm2/sec (ADC index). Quantitative histology (mean linear intercept) was obtained in 10 of the lung specimens from 10 of the subjects. Results: The mean ADCs with Diffusion Times of 1.6, 5.0, and 10.0 msec were 0.46, 0.40, and 0.37 cm2/sec, respectively (P <0.0001, ANOVA). There was no relationship between the ADC magnitude and the effect of Diffusion Time on ADC values. Mean linear intercept correlated with ADC (r=0.91-0.94, P<0.001) and ADC index (r=0.78-0.92, P<0.01) at all Diffusion Times.

  • Effects of Diffusion Time on short‐range hyperpolarized 3He diffusivity measurements in emphysema
    Journal of Magnetic Resonance Imaging, 2009
    Co-Authors: David S Gierada, Jason C Woods, Andrew J Bierhals, Seth T Bartel, Jon H Ritter, Cliff Khuat Chye Choong, Cheng Hong, Thomas K Pilgram, Yulin V. Chang
    Abstract:

    Purpose: To characterize the effect of Diffusion Time on short-range hyperpolarized 3He MR Diffusion measurements across a wide range of emphysema severity. Materials and Methods: 3He Diffusion MR imaging was performed on 19 lungs or lobes resected from 18 subjects with varying degrees of emphysema using 3 Diffusion Times (1.6 msec, 5 msec, and 10 msec) at constant b value. Emphysema severity was quantified as the mean apparent Diffusion coefficient (ADC) and as the percentage of pixels with ADC higher than multiple thresholds from 0.30-0.55 cm2/sec (ADC index). Quantitative histology (mean linear intercept) was obtained in 10 of the lung specimens from 10 of the subjects. Results: The mean ADCs with Diffusion Times of 1.6, 5.0, and 10.0 msec were 0.46, 0.40, and 0.37 cm2/sec, respectively (P

Cheng Hong - One of the best experts on this subject based on the ideXlab platform.

  • effects of Diffusion Time on short range hyperpolarized 3he diffusivity measurements in emphysema
    Journal of Magnetic Resonance Imaging, 2009
    Co-Authors: David S Gierada, Jason C Woods, Andrew J Bierhals, Seth T Bartel, Jon H Ritter, Cliff Khuat Chye Choong, Cheng Hong, Thomas K Pilgram
    Abstract:

    Purpose: To characterize the effect of Diffusion Time on short-range hyperpolarized 3He MR Diffusion measurements across a wide range of emphysema severity. Materials and Methods: 3He Diffusion MR imaging was performed on 19 lungs or lobes resected from 18 subjects with varying degrees of emphysema using 3 Diffusion Times (1.6 msec, 5 msec, and 10 msec) at constant b value. Emphysema severity was quantified as the mean apparent Diffusion coefficient (ADC) and as the percentage of pixels with ADC higher than multiple thresholds from 0.30-0.55 cm2/sec (ADC index). Quantitative histology (mean linear intercept) was obtained in 10 of the lung specimens from 10 of the subjects. Results: The mean ADCs with Diffusion Times of 1.6, 5.0, and 10.0 msec were 0.46, 0.40, and 0.37 cm2/sec, respectively (P <0.0001, ANOVA). There was no relationship between the ADC magnitude and the effect of Diffusion Time on ADC values. Mean linear intercept correlated with ADC (r=0.91-0.94, P<0.001) and ADC index (r=0.78-0.92, P<0.01) at all Diffusion Times.

  • Effects of Diffusion Time on short‐range hyperpolarized 3He diffusivity measurements in emphysema
    Journal of Magnetic Resonance Imaging, 2009
    Co-Authors: David S Gierada, Jason C Woods, Andrew J Bierhals, Seth T Bartel, Jon H Ritter, Cliff Khuat Chye Choong, Cheng Hong, Thomas K Pilgram, Yulin V. Chang
    Abstract:

    Purpose: To characterize the effect of Diffusion Time on short-range hyperpolarized 3He MR Diffusion measurements across a wide range of emphysema severity. Materials and Methods: 3He Diffusion MR imaging was performed on 19 lungs or lobes resected from 18 subjects with varying degrees of emphysema using 3 Diffusion Times (1.6 msec, 5 msec, and 10 msec) at constant b value. Emphysema severity was quantified as the mean apparent Diffusion coefficient (ADC) and as the percentage of pixels with ADC higher than multiple thresholds from 0.30-0.55 cm2/sec (ADC index). Quantitative histology (mean linear intercept) was obtained in 10 of the lung specimens from 10 of the subjects. Results: The mean ADCs with Diffusion Times of 1.6, 5.0, and 10.0 msec were 0.46, 0.40, and 0.37 cm2/sec, respectively (P