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Ling Shao - One of the best experts on this subject based on the ideXlab platform.
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coding artifact reduction using non reference block grid visibility measure
International Conference on Multimedia and Expo, 2006Co-Authors: Ihor Olehovych Kirenko, R Muijs, Ling ShaoAbstract: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.
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ICME - Coding Artifact Reduction using Non-Reference Block Grid Visibility Measure
2006 IEEE International Conference on Multimedia and Expo, 2006Co-Authors: Ihor Olehovych Kirenko, R Muijs, Ling ShaoAbstract: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.
Ihor Olehovych Kirenko - One of the best experts on this subject based on the ideXlab platform.
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coding artifact reduction using non reference block grid visibility measure
International Conference on Multimedia and Expo, 2006Co-Authors: Ihor Olehovych Kirenko, R Muijs, Ling ShaoAbstract: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.
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ICME - Coding Artifact Reduction using Non-Reference Block Grid Visibility Measure
2006 IEEE International Conference on Multimedia and Expo, 2006Co-Authors: Ihor Olehovych Kirenko, R Muijs, Ling ShaoAbstract: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.
Taichiu Hsung - One of the best experts on this subject based on the ideXlab platform.
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A deblocking technique for block-transform compressed Image using wavelet transform modulus maxima
IEEE transactions on image processing : a publication of the IEEE Signal Processing Society, 1998Co-Authors: Taichiu Hsung, D. Pak-kong Lun, Wanchi SiuAbstract:We introduce a deblocking algorithm for Joint Photographic Experts Group (JPEG) Decoded Images using the wavelet transform modulus maxima (WTMM) representation. Under the WTMM representation, we can characterize the blocking effect of a JPEG Decoded Image as: (1) small modulus maxima at block boundaries over smooth regions; (2) noise or irregular structures near strong edges; and (3) corrupted edges across block boundaries. The WTMM representation not only provides characterization of the blocking effect, but also enables simple and local operations to reduce the adverse effect due to this problem. The proposed algorithm first performs a segmentation on a JPEG Decoded Image to identify the texture regions by noting that their WTMM have small variation in regularity. We do not process the modulus maxima of these regions, to avoid the Image texture being "oversmoothed" by the algorithm. Then, the singularities in the remaining regions of the blocky Image and the small modulus maxima at block boundaries are removed. We link up the corrupted edges, and regularize the phase of modulus maxima as well as the magnitude of strong edges. Finally, the Image is reconstructed using the projection onto convex set (POCS) technique on the processed WTMM of that JPEG Decoded Image. This simple algorithm improves the quality of a JPEG Decoded Image in the senses of the signal-to-noise ratio (SNR) as well as the visual quality. We also compare the performance of our algorithm to the previous approaches, such as CLS and POCS methods. The most remarkable advantage of the WTMM deblocking algorithm is that we can directly process the edges and texture of an Image using its WTMM representation.
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a deblocking technique for jpeg Decoded Image using wavelet transform modulus maxima representation
International Conference on Image Processing, 1996Co-Authors: Taichiu Hsung, Pakkong D Lun, Wanchi SiuAbstract:In this paper, we introduce a local deblocking algorithm for JPEG Decoded Images using the wavelet transform modulus maxima (WTMM) representation. Under the WTMM representation, we can characterize the blocking effect as: 1) small modulus maxima at block boundaries over smooth regions; 2) noises or irregular structures near strong edges; 3) corrupted edges across block boundaries. The WTMM representation not only provides characterization of the blocking effect, but also enables simple and local operations on those singularities. The proposed algorithm first performs a segmentation to discriminate the texture regions of an Image based on the WTMM local regularity variance. We then keep the modulus maxima of these regions, which are of low regularity variation, unchange to avoid the Image texture being "over-smoothed" by the algorithm. Then, the singularities on the remaining regions of the blocky Image and small modulus maxima at block boundaries are removed. Then, we link up the corrupted edges and regularize the phase of modulus maxima as well as the amplitude of strong edges. Finally, the Image is reconstructed using the projection onto convex sets (POCS) technique on the processed WTMM of the JPEG Decoded Image. This simple algorithm improves the quality of JPEG Decoded Image in the sense of signal to noise ratio as well as visual quality. We also compare the performance of our algorithm with the previous approaches and show the superiority over them. The most remarkable advantage of the WTMM deblocking algorithm is that it incorporates direct edges and texture operations into the WTMM representation.
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ICIP (2) - A deblocking technique for JPEG Decoded Image using wavelet transform modulus maxima representation
Proceedings of 3rd IEEE International Conference on Image Processing, 1Co-Authors: Taichiu Hsung, D. Pak-kong Lun, Wanchi SiuAbstract:In this paper, we introduce a local deblocking algorithm for JPEG Decoded Images using the wavelet transform modulus maxima (WTMM) representation. Under the WTMM representation, we can characterize the blocking effect as: 1) small modulus maxima at block boundaries over smooth regions; 2) noises or irregular structures near strong edges; 3) corrupted edges across block boundaries. The WTMM representation not only provides characterization of the blocking effect, but also enables simple and local operations on those singularities. The proposed algorithm first performs a segmentation to discriminate the texture regions of an Image based on the WTMM local regularity variance. We then keep the modulus maxima of these regions, which are of low regularity variation, unchange to avoid the Image texture being "over-smoothed" by the algorithm. Then, the singularities on the remaining regions of the blocky Image and small modulus maxima at block boundaries are removed. Then, we link up the corrupted edges and regularize the phase of modulus maxima as well as the amplitude of strong edges. Finally, the Image is reconstructed using the projection onto convex sets (POCS) technique on the processed WTMM of the JPEG Decoded Image. This simple algorithm improves the quality of JPEG Decoded Image in the sense of signal to noise ratio as well as visual quality. We also compare the performance of our algorithm with the previous approaches and show the superiority over them. The most remarkable advantage of the WTMM deblocking algorithm is that it incorporates direct edges and texture operations into the WTMM representation.
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Image denoising using wavelet transform modulus sum
ICSP '98. 1998 Fourth International Conference on Signal Processing (Cat. No.98TH8344), 1Co-Authors: D. Pak-kong Lun, Taichiu HsungAbstract:For conventional MPEG-1 video decoding, one of the major sources of noise appearing in the Decoded Image sequence is the blocking effect, which is incurred by the quantization errors of the Image blocks of the key frames. Recently, the wavelet transform modulus maxima (WTMM) approach was proposed to significantly reduce the blocking effect of the Decoded Image sequence. This algorithm improves the quality of the Decoded Image sequence in the sense of signal-to-noise ratio as well as visual quality. Nonetheless, the WTMM deblocking algorithm is an iterative algorithm that requires a long computation time to reconstruct the processed WTMM to obtain the deblocked Image. In this paper, another wavelet-based deblocking algorithm is studied. The algorithm has the advantage of the WTMM approach that it can effectively identify the edges and the smooth regions of an Image irrespective the discontinuities introduced by the blocking effect. It improves over the WTMM approach in that only a simple inverse wavelet transform is required to reconstruct the processed wavelet coefficients to obtain the deblocked Image sequence.
Wanchi Siu - One of the best experts on this subject based on the ideXlab platform.
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A deblocking technique for block-transform compressed Image using wavelet transform modulus maxima
IEEE transactions on image processing : a publication of the IEEE Signal Processing Society, 1998Co-Authors: Taichiu Hsung, D. Pak-kong Lun, Wanchi SiuAbstract:We introduce a deblocking algorithm for Joint Photographic Experts Group (JPEG) Decoded Images using the wavelet transform modulus maxima (WTMM) representation. Under the WTMM representation, we can characterize the blocking effect of a JPEG Decoded Image as: (1) small modulus maxima at block boundaries over smooth regions; (2) noise or irregular structures near strong edges; and (3) corrupted edges across block boundaries. The WTMM representation not only provides characterization of the blocking effect, but also enables simple and local operations to reduce the adverse effect due to this problem. The proposed algorithm first performs a segmentation on a JPEG Decoded Image to identify the texture regions by noting that their WTMM have small variation in regularity. We do not process the modulus maxima of these regions, to avoid the Image texture being "oversmoothed" by the algorithm. Then, the singularities in the remaining regions of the blocky Image and the small modulus maxima at block boundaries are removed. We link up the corrupted edges, and regularize the phase of modulus maxima as well as the magnitude of strong edges. Finally, the Image is reconstructed using the projection onto convex set (POCS) technique on the processed WTMM of that JPEG Decoded Image. This simple algorithm improves the quality of a JPEG Decoded Image in the senses of the signal-to-noise ratio (SNR) as well as the visual quality. We also compare the performance of our algorithm to the previous approaches, such as CLS and POCS methods. The most remarkable advantage of the WTMM deblocking algorithm is that we can directly process the edges and texture of an Image using its WTMM representation.
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a deblocking technique for jpeg Decoded Image using wavelet transform modulus maxima representation
International Conference on Image Processing, 1996Co-Authors: Taichiu Hsung, Pakkong D Lun, Wanchi SiuAbstract:In this paper, we introduce a local deblocking algorithm for JPEG Decoded Images using the wavelet transform modulus maxima (WTMM) representation. Under the WTMM representation, we can characterize the blocking effect as: 1) small modulus maxima at block boundaries over smooth regions; 2) noises or irregular structures near strong edges; 3) corrupted edges across block boundaries. The WTMM representation not only provides characterization of the blocking effect, but also enables simple and local operations on those singularities. The proposed algorithm first performs a segmentation to discriminate the texture regions of an Image based on the WTMM local regularity variance. We then keep the modulus maxima of these regions, which are of low regularity variation, unchange to avoid the Image texture being "over-smoothed" by the algorithm. Then, the singularities on the remaining regions of the blocky Image and small modulus maxima at block boundaries are removed. Then, we link up the corrupted edges and regularize the phase of modulus maxima as well as the amplitude of strong edges. Finally, the Image is reconstructed using the projection onto convex sets (POCS) technique on the processed WTMM of the JPEG Decoded Image. This simple algorithm improves the quality of JPEG Decoded Image in the sense of signal to noise ratio as well as visual quality. We also compare the performance of our algorithm with the previous approaches and show the superiority over them. The most remarkable advantage of the WTMM deblocking algorithm is that it incorporates direct edges and texture operations into the WTMM representation.
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ICIP (2) - A deblocking technique for JPEG Decoded Image using wavelet transform modulus maxima representation
Proceedings of 3rd IEEE International Conference on Image Processing, 1Co-Authors: Taichiu Hsung, D. Pak-kong Lun, Wanchi SiuAbstract:In this paper, we introduce a local deblocking algorithm for JPEG Decoded Images using the wavelet transform modulus maxima (WTMM) representation. Under the WTMM representation, we can characterize the blocking effect as: 1) small modulus maxima at block boundaries over smooth regions; 2) noises or irregular structures near strong edges; 3) corrupted edges across block boundaries. The WTMM representation not only provides characterization of the blocking effect, but also enables simple and local operations on those singularities. The proposed algorithm first performs a segmentation to discriminate the texture regions of an Image based on the WTMM local regularity variance. We then keep the modulus maxima of these regions, which are of low regularity variation, unchange to avoid the Image texture being "over-smoothed" by the algorithm. Then, the singularities on the remaining regions of the blocky Image and small modulus maxima at block boundaries are removed. Then, we link up the corrupted edges and regularize the phase of modulus maxima as well as the amplitude of strong edges. Finally, the Image is reconstructed using the projection onto convex sets (POCS) technique on the processed WTMM of the JPEG Decoded Image. This simple algorithm improves the quality of JPEG Decoded Image in the sense of signal to noise ratio as well as visual quality. We also compare the performance of our algorithm with the previous approaches and show the superiority over them. The most remarkable advantage of the WTMM deblocking algorithm is that it incorporates direct edges and texture operations into the WTMM representation.
Noriyoshi Kambayashi - One of the best experts on this subject based on the ideXlab platform.
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ISCAS (2) - Optimum word length allocation for multipliers of integer DCT.
2003Co-Authors: Masahiro Iwahashi, Osamu Nishida, Somchart Chokchaitam, Noriyoshi KambayashiAbstract:Recently, the integer DCT (Int-DCT), which has the rounding operations in the lifting structure, is attracting many researchers' attention as an effective method for DCT based lossy / lossless unified coding. So far, focuses of the previous reports relevant to the Int-DCT have been limited to a few topics such as how to reduce the number of multipliers with the four point lossless Hadamard transform and the non-separable two dimensional LDCT. What seems to be lacking, however, is how to express multipliers' word length as short as possible for reduction of hardware complexity. This report defines a new "SNR sensitivity" as an indicator of how the word length truncation of multiplier coefficients affects quality of the Decoded Image, and also proposes a new word length allocation method based on the sensitivity. As a result, two [bit] in average shorter word length is attained under equivalent quality of the Decoded Image.
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Optimum word length allocation for multipliers of integer DCT [Image coding]
Proceedings of the 2003 International Symposium on Circuits and Systems 2003. ISCAS '03., 1Co-Authors: Masahiro Iwahashi, Osamu Nishida, Somchart Chokchaitam, Noriyoshi KambayashiAbstract:Recently, the integer DCT (Int-DCT), which has rounding operations in the lifting structure, is attracting many researchers attention as an effective method for DCT based lossy/lossless unified coding. So far, focuses of the previous reports relevant to the Int-DCT have been limited to a few topics such as how to reduce the number of multipliers with the four point lossless Hadamard transform and the non-separable two dimensional LDCT. What seems to be lacking, however, is how to express multiplier word length as short as possible for reduction of hardware complexity. This report defines a new "SNR sensitivity" as an indicator of how the word length truncation of multiplier coefficients affects quality of the Decoded Image, and also proposes a new word length allocation method based on the sensitivity. As a result, two [bit] on average shorter word length is attained under equivalent quality of the Decoded Image.
