The Experts below are selected from a list of 32007 Experts worldwide ranked by ideXlab platform

James D Thomas - One of the best experts on this subject based on the ideXlab platform.

  • Digital Compression of echocardiograms: Impact on quantitative interpretation of color doppler velocity
    Journal of The American Society of Echocardiography, 1996
    Co-Authors: James D Thomas, Shalabh Chandra, Tom H. Karson, Min Pu, Pieter M. Vandervoort
    Abstract:

    Abstract To test the impact of Joint Photographic Expert Group (JPEG) Compression on the quantitative data encoded in color Doppler echocardiographic images, Digital images from transesophageal echocardiography and an in vitro model of proximal flow convergence were analyzed before and after JPEG Compression with Compression ratios (CRs) as high as 65:1. Even at the highest CRs, greater than 95% of the pixels were categorized correctly as representing structure (gray scale) and greater than 98% were categorized correctly as representing velocity (color) data. Furthermore, the velocities and flows recovered from the compressed images agreed well ( r = 0.998 [velocities] and r = 0.998 [flows] for CR=7:1, falling to r = 0.881 [velocities] and r = 0.930 [flows] at CR=65:1; p

  • Digital storage of echocardiograms offers superior image quality to analog storage, even with 20:1 Digital Compression: Results of the Digital echo record access study
    Journal of the American Society of Echocardiography, 1996
    Co-Authors: Tom H. Karson, Shalabh Chandra, Richard C. Zepp, Annitta Morchead, James D Thomas
    Abstract:

    A large interobserver and intraobserver variability study was performed comparing both Digitally compressed and uncompressed echocardiographic images with the same images recorded onto super-VHS video-cassette tape (the current standard). In a blinded, randomized fashion, 179 observers scored the diagnostic and image quality of 20 pairs of echocardiographic loops representing various pathologic conditions. Overall, the Digital images were preferred to the S-VHS images both for image quality and diagnostic content (p < 0.0001) regardless of the background or experience level of the observer. Furthermore, uncompressed Digital images and those compressed by the Joint Photographic Experts Group (JPEG) algorithm at ratios of 20:1 were judged equivalent. These findings show that Digital Compression may be used routinely in echocardiography, resulting in improved image and diagnostic quality over present standards.

  • Digital Compression of echocardiographic images: is it viable?
    Proceedings of Computers in Cardiology Conference, 1
    Co-Authors: Tom H. Karson, Shalabh Chandra, Annitta Morehead, S.e. Nissen, James D Thomas
    Abstract:

    The degree of information loss by Compression of echocardiographic images utilizing the Joint Photographic Experts Group (JPEG) baseline system was evaluated using objective fidelity criteria. Standard echocardiograms were acquired Digitally in real-time and stored on optical disk. 180 still frame images were processed in software using 5 preset quantization tables yielding average Compression ratios of 7:1, 10:1, 17:1, 30:1 and 36:1. Objective parameters evaluated include the root mean square error (RMSE), signal-to-noise ratio (SNR), difference image mean and maximal pixel value shift. The mean pixel values and standard deviations of all images over all levels of Compression were very similar. Even for ratios as high as 35:1, no significant bias was introduced in the pixel intensity values. Average RMSE ranged from 1.27 to 7.89 while average SNR ranged from 38.81 to 22.93. The data shows that JPEG Compression at high ratios does not significantly alter objective image content and is a potential solution for reducing Digital storage requirements. >

Jin-man Cho - One of the best experts on this subject based on the ideXlab platform.

Kyu-tae Yang - One of the best experts on this subject based on the ideXlab platform.

  • The Conditional Access Flow Using Smart Card With KOREASAT Digital DBS Receiver
    International Conference on Consumer Electronics, 1997
    Co-Authors: Kyu-tae Yang, Dong-hee Han, Jin-ho Kim, Nak-seen Seong, Jin-man Cho
    Abstract:

    The KOREASAT Digital DBS System adopted MPEG-2 Digital Compression and multiplex. The KOREASAT Digital DBS system provides a conditional access service. The conditional access service is that only subscribers who pay receiving fee can watch programs. This paper presents the conditional access flow mechanism using subscriber smart card with KOREASAT Digital DBS Receiver.

  • The conditional access flow using subscriber smart card with Koreasat DBS receiver
    IEEE Transactions on Consumer Electronics, 1997
    Co-Authors: Kyu-tae Yang, Dong-hee Han, Jin-ho Kim, Jin-man Cho
    Abstract:

    The Koreasat DBS system has adopted MPEG-2 Digital Compression and multiplexing. It provides conditional access services using a security device such as a smart card. The conditional access services permit that only subscribers who pay the receiving fee can watch programs. This paper presents the conditional access flow using the subscriber smart card with the Koreasat DBS receiver.

  • The design and implementation of Koreasat DBS set-top-box software
    Proceedings of ICICS 1997 International Conference on Information Communications and Signal Processing. Theme: Trends in Information Systems Engineeri, 1
    Co-Authors: Kyu-tae Yang, Dong-hee Han
    Abstract:

    The Koreasat DBS system adopted MPEG-2 Digital Compression and multiplexing. This system has been broadcasting test programs since July 1, 1996. A Koreasat DBS receiver is necessary in order to receive these programs. The Koreasat DBS receiver consists of a 45 cm antenna, LNB, infrared remote controller, subscriber smart card, and set-top-box. This paper presents the design and implementation of Koreasat DBS set-top-box software.

Tom H. Karson - One of the best experts on this subject based on the ideXlab platform.

  • Digital Compression of echocardiograms: Impact on quantitative interpretation of color doppler velocity
    Journal of The American Society of Echocardiography, 1996
    Co-Authors: James D Thomas, Shalabh Chandra, Tom H. Karson, Min Pu, Pieter M. Vandervoort
    Abstract:

    Abstract To test the impact of Joint Photographic Expert Group (JPEG) Compression on the quantitative data encoded in color Doppler echocardiographic images, Digital images from transesophageal echocardiography and an in vitro model of proximal flow convergence were analyzed before and after JPEG Compression with Compression ratios (CRs) as high as 65:1. Even at the highest CRs, greater than 95% of the pixels were categorized correctly as representing structure (gray scale) and greater than 98% were categorized correctly as representing velocity (color) data. Furthermore, the velocities and flows recovered from the compressed images agreed well ( r = 0.998 [velocities] and r = 0.998 [flows] for CR=7:1, falling to r = 0.881 [velocities] and r = 0.930 [flows] at CR=65:1; p

  • Digital storage of echocardiograms offers superior image quality to analog storage, even with 20:1 Digital Compression: Results of the Digital echo record access study
    Journal of the American Society of Echocardiography, 1996
    Co-Authors: Tom H. Karson, Shalabh Chandra, Richard C. Zepp, Annitta Morchead, James D Thomas
    Abstract:

    A large interobserver and intraobserver variability study was performed comparing both Digitally compressed and uncompressed echocardiographic images with the same images recorded onto super-VHS video-cassette tape (the current standard). In a blinded, randomized fashion, 179 observers scored the diagnostic and image quality of 20 pairs of echocardiographic loops representing various pathologic conditions. Overall, the Digital images were preferred to the S-VHS images both for image quality and diagnostic content (p < 0.0001) regardless of the background or experience level of the observer. Furthermore, uncompressed Digital images and those compressed by the Joint Photographic Experts Group (JPEG) algorithm at ratios of 20:1 were judged equivalent. These findings show that Digital Compression may be used routinely in echocardiography, resulting in improved image and diagnostic quality over present standards.

  • Digital Compression of echocardiographic images: is it viable?
    Proceedings of Computers in Cardiology Conference, 1
    Co-Authors: Tom H. Karson, Shalabh Chandra, Annitta Morehead, S.e. Nissen, James D Thomas
    Abstract:

    The degree of information loss by Compression of echocardiographic images utilizing the Joint Photographic Experts Group (JPEG) baseline system was evaluated using objective fidelity criteria. Standard echocardiograms were acquired Digitally in real-time and stored on optical disk. 180 still frame images were processed in software using 5 preset quantization tables yielding average Compression ratios of 7:1, 10:1, 17:1, 30:1 and 36:1. Objective parameters evaluated include the root mean square error (RMSE), signal-to-noise ratio (SNR), difference image mean and maximal pixel value shift. The mean pixel values and standard deviations of all images over all levels of Compression were very similar. Even for ratios as high as 35:1, no significant bias was introduced in the pixel intensity values. Average RMSE ranged from 1.27 to 7.89 while average SNR ranged from 38.81 to 22.93. The data shows that JPEG Compression at high ratios does not significantly alter objective image content and is a potential solution for reducing Digital storage requirements. >

Dong-hee Han - One of the best experts on this subject based on the ideXlab platform.

  • The Conditional Access Flow Using Smart Card With KOREASAT Digital DBS Receiver
    International Conference on Consumer Electronics, 1997
    Co-Authors: Kyu-tae Yang, Dong-hee Han, Jin-ho Kim, Nak-seen Seong, Jin-man Cho
    Abstract:

    The KOREASAT Digital DBS System adopted MPEG-2 Digital Compression and multiplex. The KOREASAT Digital DBS system provides a conditional access service. The conditional access service is that only subscribers who pay receiving fee can watch programs. This paper presents the conditional access flow mechanism using subscriber smart card with KOREASAT Digital DBS Receiver.

  • The conditional access flow using subscriber smart card with Koreasat DBS receiver
    IEEE Transactions on Consumer Electronics, 1997
    Co-Authors: Kyu-tae Yang, Dong-hee Han, Jin-ho Kim, Jin-man Cho
    Abstract:

    The Koreasat DBS system has adopted MPEG-2 Digital Compression and multiplexing. It provides conditional access services using a security device such as a smart card. The conditional access services permit that only subscribers who pay the receiving fee can watch programs. This paper presents the conditional access flow using the subscriber smart card with the Koreasat DBS receiver.

  • The design and implementation of Koreasat DBS set-top-box software
    Proceedings of ICICS 1997 International Conference on Information Communications and Signal Processing. Theme: Trends in Information Systems Engineeri, 1
    Co-Authors: Kyu-tae Yang, Dong-hee Han
    Abstract:

    The Koreasat DBS system adopted MPEG-2 Digital Compression and multiplexing. This system has been broadcasting test programs since July 1, 1996. A Koreasat DBS receiver is necessary in order to receive these programs. The Koreasat DBS receiver consists of a 45 cm antenna, LNB, infrared remote controller, subscriber smart card, and set-top-box. This paper presents the design and implementation of Koreasat DBS set-top-box software.