The Experts below are selected from a list of 81 Experts worldwide ranked by ideXlab platform

Ling Shao - One of the best experts on this subject based on the ideXlab platform.

  • MMM (1) - A generalized Coding Artifacts and noise removal algorithm for digitally compressed video signals
    Lecture Notes in Computer Science, 2011
    Co-Authors: Ling Shao, Hui Zhang
    Abstract:

    A generalized Coding Artifact reduction algorithm is proposed for a variety of Artifacts, including blocking Artifact, ringing Artifact and mosquito noise. This algorithm does not require grid position detection and any Coding parameters. All the filtering is based on local content analysis. Basically, the algorithm attempts to apply mild low-pass filtering on more informative regions to preserve the sharpness of the object details, and to apply strong low-pass filtering on less informative regions to remove severe Artifacts. The size and parameters of the low-pass filters are changed continuously based on the entropy of a local region.

  • simultaneous Coding Artifact reduction and sharpness enhancement for block based compressed images and videos
    Signal Processing-image Communication, 2008
    Co-Authors: Ling Shao
    Abstract:

    In this paper, an efficient least mean square (LMS) optimization algorithm based on the ordering of pixels is proposed for simultaneous sharpness enhancement and Coding Artifact reduction. The pixels in a filter aperture are ordered according to their spatial distances and intensity deviations to the central pixel. The optimized filter coefficients for the ordered pixels are obtained by training on a dataset that is composed of the original images and the compressed blurred versions of the original images. The pixel ordering procedure makes the algorithm more efficient for training and much cheaper in terms of classification than other LMS techniques. Experimental results show the superior performance of the proposed algorithm to the state-of-the-art classification-based techniques.

  • Coding Artifact reduction based on local entropy analysis
    IEEE Transactions on Consumer Electronics, 2007
    Co-Authors: Ling Shao, Ihor Olehovych Kirenko
    Abstract:

    Coding Artifacts are very annoying in highly compressed images and video sequences. Most Artifact reduction techniques blur the details of the images while removing various Coding Artifacts. In this paper, we propose a novel and explicit approach for classifying blocks into detailed regions, intermediate regions and smooth regions. The classification is based on the information content of the underlying region. The information content of a region is quantized by local entropy, which is calculated on the PDF of the pixel intensity distribution. Local entropy is used as an indicator of how much smoothing is needed for a certain region. It is well known that blocking Artifacts are more visible in flat regions than in detailed regions. We apply mild low-pass filters on detailed regions to preserve the sharpness, and strong low-pass filters on flat regions to remove the severe blocking Artifacts. Experimental results show that our proposed algorithm can preserve the details and reduce Coding Artifacts better than more expensive state of the art techniques .

  • content adaptive Coding Artifact reduction for decompressed video and images
    International Conference on Consumer Electronics, 2007
    Co-Authors: Ling Shao, Ihor Olehovych Kirenko
    Abstract:

    Most Artifact reduction techniques blur the details of the images while removing various Coding Artifacts. In this paper, we propose a novel and explicit approach for classifying blocks into detailed regions, intermediate regions and smooth regions. The classification is based on the information content of the underlying region, which is quantized by local entropy calculated on the PDF of the pixel intensity distribution. The entropy is used as an indicator of how much smoothing is needed for a certain region. Experimental results show that our proposed algorithm can preserve the details and reduce Coding Artifacts better than more expensive state of the art techniques.

  • Coding Artifact reduction using non reference block grid visibility measure
    International Conference on Multimedia and Expo, 2006
    Co-Authors: Ihor Olehovych Kirenko, R Muijs, Ling Shao
    Abstract:

    In this work a new method is proposed for Coding Artifact reduction of MPEG compressed video sequences. The method makes use of a simple cost-effective technique that allows the block grid position and its visibility to be determined without the need for access to the Coding parameters. This information, combined with the results of local spatial analysis of luminance and chrominance components of a decoded image, is used to effectively suppress Coding Artifacts while preserving the sharpness of object edges. Results of our experiments confirm the high efficiency of the proposed approach.

Yu Hen Hu - One of the best experts on this subject based on the ideXlab platform.

  • content based blurring Coding Artifact reduction using patch based texture synthesis image video Coding applications
    International Conference on Acoustics Speech and Signal Processing, 2004
    Co-Authors: Rajas A Sambhare, Yu Hen Hu
    Abstract:

    Blurring Artifacts occur in low bit-rate image or video Coding. This manifests itself as a blurred patch within a textured region. Previously, we proposed a constrained texture synthesis postprocessing algorithm to regenerate the texture of the blurred patch using surrounding texture of the same kind. However, a human operator must manually identify the blurred target, and a valid source region from its surroundings. In this work, we present an effort to automate this process. Specifically, we developed an efficient modified k-means algorithm method to segment and identify potentially blurred patches; and a content-based region selection method to choose the candidate source region. Preliminary experiment results indicate that our algorithm produces results consistent with that produced by a human operator.

  • content based blurring Coding Artifact reduction using patch based texture synthesis
    2004
    Co-Authors: Rajas A Sambhare, Yu Hen Hu
    Abstract:

    Blurring Artifact occurs in low bit-rate image or video Coding. It manifests itself as a blurred patch within a textured region. Previously, we proposed a constrained texture synthesis postprocessing algorithm [8] to regenerate the texture the blurred patch using surrounding texture of the same kind. However, a human operator must manually identify the blurred target, and a valid source region from its surroundings. In this work, we present an effort to automate this process. Specifically, we developed an efficient modified k-means algorithm method to segment and identify potentially blurred patches; and a contentbased region selection method to choose the candidate source region. Preliminary experiment results indicate that our algorithm produces results consistent with that produced by a human operator.

  • MMSP - Low bit rate video sequence Coding Artifact removal
    2001 IEEE Fourth Workshop on Multimedia Signal Processing (Cat. No.01TH8564), 2001
    Co-Authors: S Yang, Yu Hen Hu, S Kittitornkun, T Q Nguyen, D.l. Tull
    Abstract:

    The picture quality of video frames encoded at very low-bit rates often suffers from both blocking and ringing Artifacts. We present two post-processing methods to mitigate the visual quality degradation caused by these Artifacts. To reduce the blocking Artifact of decoded images, we substitute IDCT for the lapped orthogonal transform embedded inverse discrete cosine transform (le-IDCT). On the other hand, we post-process the decoded video frames using a nonlinear robust filter to reduce the ringing Artifact. Extensive simulation results indicated significant improvement in both objective and subjective visual qualities. The computation overhead incurred due to these quality enhancement operations is quite moderate, and can be easily optimized to achieve real-time operation.

  • low bit rate video sequence Coding Artifact removal
    Multimedia Signal Processing, 2001
    Co-Authors: S Yang, Yu Hen Hu, S Kittitornkun, T Q Nguyen, D.l. Tull
    Abstract:

    The picture quality of video frames encoded at very low-bit rates often suffers from both blocking and ringing Artifacts. We present two post-processing methods to mitigate the visual quality degradation caused by these Artifacts. To reduce the blocking Artifact of decoded images, we substitute IDCT for the lapped orthogonal transform embedded inverse discrete cosine transform (le-IDCT). On the other hand, we post-process the decoded video frames using a nonlinear robust filter to reduce the ringing Artifact. Extensive simulation results indicated significant improvement in both objective and subjective visual qualities. The computation overhead incurred due to these quality enhancement operations is quite moderate, and can be easily optimized to achieve real-time operation.

  • MMSP - Blocking effect removal using robust statistics and line process
    1999 IEEE Third Workshop on Multimedia Signal Processing (Cat. No.99TH8451), 1999
    Co-Authors: Seungjoon Yang, Yu Hen Hu, D.l. Tull
    Abstract:

    The Gibbs distribution with spatially adaptive clique potential functions is used as the image prior distribution in the Coding Artifact reduction problem. Unlike previous approaches, the image is divided in regions based on the local statistics and a clique potential function is assigned for each region. A non-differentiable potential function that preserves edge in detailed image regions is introduced. Images recovered by the proposed approach contain reduced Coding Artifact and improved preservation of details.

Ihor Olehovych Kirenko - One of the best experts on this subject based on the ideXlab platform.

  • Coding Artifact reduction based on local entropy analysis
    IEEE Transactions on Consumer Electronics, 2007
    Co-Authors: Ling Shao, Ihor Olehovych Kirenko
    Abstract:

    Coding Artifacts are very annoying in highly compressed images and video sequences. Most Artifact reduction techniques blur the details of the images while removing various Coding Artifacts. In this paper, we propose a novel and explicit approach for classifying blocks into detailed regions, intermediate regions and smooth regions. The classification is based on the information content of the underlying region. The information content of a region is quantized by local entropy, which is calculated on the PDF of the pixel intensity distribution. Local entropy is used as an indicator of how much smoothing is needed for a certain region. It is well known that blocking Artifacts are more visible in flat regions than in detailed regions. We apply mild low-pass filters on detailed regions to preserve the sharpness, and strong low-pass filters on flat regions to remove the severe blocking Artifacts. Experimental results show that our proposed algorithm can preserve the details and reduce Coding Artifacts better than more expensive state of the art techniques .

  • content adaptive Coding Artifact reduction for decompressed video and images
    International Conference on Consumer Electronics, 2007
    Co-Authors: Ling Shao, Ihor Olehovych Kirenko
    Abstract:

    Most Artifact reduction techniques blur the details of the images while removing various Coding Artifacts. In this paper, we propose a novel and explicit approach for classifying blocks into detailed regions, intermediate regions and smooth regions. The classification is based on the information content of the underlying region, which is quantized by local entropy calculated on the PDF of the pixel intensity distribution. The entropy is used as an indicator of how much smoothing is needed for a certain region. Experimental results show that our proposed algorithm can preserve the details and reduce Coding Artifacts better than more expensive state of the art techniques.

  • Coding Artifact reduction using non reference block grid visibility measure
    International Conference on Multimedia and Expo, 2006
    Co-Authors: Ihor Olehovych Kirenko, R Muijs, Ling Shao
    Abstract:

    In this work a new method is proposed for Coding Artifact reduction of MPEG compressed video sequences. The method makes use of a simple cost-effective technique that allows the block grid position and its visibility to be determined without the need for access to the Coding parameters. This information, combined with the results of local spatial analysis of luminance and chrominance components of a decoded image, is used to effectively suppress Coding Artifacts while preserving the sharpness of object edges. Results of our experiments confirm the high efficiency of the proposed approach.

  • ICME - Coding Artifact Reduction using Non-Reference Block Grid Visibility Measure
    2006 IEEE International Conference on Multimedia and Expo, 2006
    Co-Authors: Ihor Olehovych Kirenko, R Muijs, Ling Shao
    Abstract:

    In this work a new method is proposed for Coding Artifact reduction of MPEG compressed video sequences. The method makes use of a simple cost-effective technique that allows the block grid position and its visibility to be determined without the need for access to the Coding parameters. This information, combined with the results of local spatial analysis of luminance and chrominance components of a decoded image, is used to effectively suppress Coding Artifacts while preserving the sharpness of object edges. Results of our experiments confirm the high efficiency of the proposed approach.

  • Reduction of Coding Artifacts using chrominance and luminance spatial analysis
    2006 Digest of Technical Papers International Conference on Consumer Electronics, 2006
    Co-Authors: Ihor Olehovych Kirenko
    Abstract:

    This paper presents a new low-cost method for Coding Artifact reduction of MPEG compressed video sequences. The algorithm detects possible locations of blocking and ringing Artifacts by analyzing local spatial activity of luminance and chrominance components. The analysis explores differences in processing of luminance and chrominance during video Coding. Depending on the outcomes of the analysis, one of three low-pass filters is applied. The results of our experiments show the high efficiency of the proposed approach.

Rajas A Sambhare - One of the best experts on this subject based on the ideXlab platform.

  • content based blurring Coding Artifact reduction using patch based texture synthesis image video Coding applications
    International Conference on Acoustics Speech and Signal Processing, 2004
    Co-Authors: Rajas A Sambhare, Yu Hen Hu
    Abstract:

    Blurring Artifacts occur in low bit-rate image or video Coding. This manifests itself as a blurred patch within a textured region. Previously, we proposed a constrained texture synthesis postprocessing algorithm to regenerate the texture of the blurred patch using surrounding texture of the same kind. However, a human operator must manually identify the blurred target, and a valid source region from its surroundings. In this work, we present an effort to automate this process. Specifically, we developed an efficient modified k-means algorithm method to segment and identify potentially blurred patches; and a content-based region selection method to choose the candidate source region. Preliminary experiment results indicate that our algorithm produces results consistent with that produced by a human operator.

  • content based blurring Coding Artifact reduction using patch based texture synthesis
    2004
    Co-Authors: Rajas A Sambhare, Yu Hen Hu
    Abstract:

    Blurring Artifact occurs in low bit-rate image or video Coding. It manifests itself as a blurred patch within a textured region. Previously, we proposed a constrained texture synthesis postprocessing algorithm [8] to regenerate the texture the blurred patch using surrounding texture of the same kind. However, a human operator must manually identify the blurred target, and a valid source region from its surroundings. In this work, we present an effort to automate this process. Specifically, we developed an efficient modified k-means algorithm method to segment and identify potentially blurred patches; and a contentbased region selection method to choose the candidate source region. Preliminary experiment results indicate that our algorithm produces results consistent with that produced by a human operator.

R Muijs - One of the best experts on this subject based on the ideXlab platform.

  • Coding Artifact reduction using non reference block grid visibility measure
    International Conference on Multimedia and Expo, 2006
    Co-Authors: Ihor Olehovych Kirenko, R Muijs, Ling Shao
    Abstract:

    In this work a new method is proposed for Coding Artifact reduction of MPEG compressed video sequences. The method makes use of a simple cost-effective technique that allows the block grid position and its visibility to be determined without the need for access to the Coding parameters. This information, combined with the results of local spatial analysis of luminance and chrominance components of a decoded image, is used to effectively suppress Coding Artifacts while preserving the sharpness of object edges. Results of our experiments confirm the high efficiency of the proposed approach.

  • ICME - Coding Artifact Reduction using Non-Reference Block Grid Visibility Measure
    2006 IEEE International Conference on Multimedia and Expo, 2006
    Co-Authors: Ihor Olehovych Kirenko, R Muijs, Ling Shao
    Abstract:

    In this work a new method is proposed for Coding Artifact reduction of MPEG compressed video sequences. The method makes use of a simple cost-effective technique that allows the block grid position and its visibility to be determined without the need for access to the Coding parameters. This information, combined with the results of local spatial analysis of luminance and chrominance components of a decoded image, is used to effectively suppress Coding Artifacts while preserving the sharpness of object edges. Results of our experiments confirm the high efficiency of the proposed approach.