• Journal of Broadcast Engineering
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• v.10 no.3
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• pp.321-327
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• 2005

A MVC (Multi-view Video Coding) method, which uses both an illumination change-adaptive ME (Motion Estimation)/DC (Motion Compensation) and a 2D (Dimensional) direct mode, is proposed. Firstly, a new SAD (Sum of Absolute Difference) measure for ME/MC is proposed to compensate the Luma pixel value changes for spatio-temporal motion vector prediction. Illumination change-adaptive (ICA) ME/MC uses the new SAD to improve both MV (Motion Vector) accuracy and bit saving. Secondly, The proposed 2D direct mode that can be used in inter-view prediction is an extended version of the temporal direct mode in MPEG-4 AVC. The proposed MVC method obtains approximately 0.8dB PSNR (Peak Signal-to-Noise Ratio) increment compared with the MPEG-4 AVC simulcast coding.

• Journal of Broadcast Engineering
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• v.14 no.5
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• pp.551-560
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• 2009

This paper proposes a method for efficient lossless depth map coding for MPEG 3D-Video coding. In general, the conventional video coding method such as H.264 has been used for depth map coding. However, the conventional video coding methods do not consider the image characteristics of the depth map. Therefore, as a lossless depth map coding method, this paper proposes a bit-plane based lossless depth mar coding method by using the MPEG-4 Part 2 shape coding scheme. Simulation results show that the proposed method achieves the compression ratios of 28.91:1. In intra-only coding, proposed method reduces the bitrate by 24.84% in comparison with the JPEG-LS scheme, by 39.35% in comparison with the JPEG-2000 scheme, by 30.30% in comparison with the H.264(CAVLC mode) scheme, and by 16.65% in comparison with the H.264(CABAC mode) scheme. In addition, in intra and inter coding the proposed method reduces the bitrate by 36.22% in comparison with the H.264(CAVLC mode) scheme, and by 23.71% in comparison with the 0.264(CABAC mode) scheme.

• Journal of Broadcast Engineering
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• v.20 no.4
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• pp.509-520
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• 2015

A design for the merge mode of three dimensional High Efficiency Video Coding (3D-HEVC) is proposed in this paper. The proposed design can reduce the implementation complexity by removing the duplicated modules of the HEVC. For the extension codec, the implementation complexity is as crucial as coding efficiency, meaning if possible, extension codec needs to be easily implemented through by reusing the design of the legacy codec as-is. However, the existing merging process of 3D-HEVC had been built-in integrated in the inside of the HEVC merging process. Thus the duplicated merging process of HEVC had to be fully re-implemented in the 3D-HEVC. Consequently the implementation complexity of the extension codec was very high. The proposed 3D-HEVC merge mode is divided into following two stages; the process to reuse the HEVC modules without any modification; and the reprocessing process for newly added and modified merging modules in 3D-HEVC. By applying the proposed method, the re-implemented HEVC modules, which accounted for 51.4% of 3D-HEVC merge mode confirmed through the operational analysis of algorithm, can be eliminated, while maintaining the same coding efficiency and computational complexity.

• Journal of Broadcast Engineering
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• v.13 no.3
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• pp.289-298
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• 2008

We propose an SNR-scalable coding algorithm for three-dimensional mesh sequences based on singular value decomposition (SVD). SVD achieves a coding gain by representing a mesh sequence with a small number of basis vectors and singular values. First, we introduce a bit plane coding scheme and derive a quantitative relationship between each bit plane and the reconstructed image quality. Using the relationship, we develop a rate-distortion (RD) optimized coding algorithm. Moreover, we propose prediction techniques to exploit the spatio-temporal correlations in real mesh sequences. Simulation results demonstrate that the proposed algorithm provides significantly better RD performance than conventional SVD coders.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.2
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• pp.763-774
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• 2015

Hand posture recognition has been a wide region of applications in Human Computer Interaction and Computer Vision for many years. The problem arises mainly due to the high dexterity of hand and self-occlusions created in the limited view of the camera or illumination variations. To remedy these problems, a hand posture recognition method using 3-D point cloud is proposed to explicitly utilize 3-D information from depth maps in this paper. Firstly, hand region is segmented by a set of depth threshold. Next, hand image normalization will be performed to ensure that the extracted feature descriptors are scale and rotation invariant. By robustly coding and pooling 3-D facets, the proposed descriptor can effectively represent the various hand postures. After that, SVM with Gaussian kernel function is used to address the issue of posture recognition. Experimental results based on posture dataset captured by Kinect sensor (from 1 to 10) demonstrate the effectiveness of the proposed approach and the average recognition rate of our method is over 96%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.3
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• pp.1140-1154
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• 2015

Multiple Description (MD) coding is a promising alternative for the robust transmission of information over error-prone channels. Lattice vector quantization (LVQ) is a significant version of MD techniques to design an MD image coder. However, different from the traditional 2D texture image, the 3D depth image has its own special characteristics, which should be taken into account for efficient compression. In this paper, an optimized MDLVQ scheme is proposed in view of the characteristics of 3D depth image. First, due to the sparsity of depth image, the image blocks can be classified into edge blocks and smooth blocks, which are encoded by different modes. Furthermore, according to the boundary contents in edge blocks, the step size of LVQ can be regulated adaptively for each block. Experimental results validate the effectiveness of the proposed scheme, which show better rate distortion performance compared with the conventional MDLVQ.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.59-63
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• 2005

We propose non-DC-free generalized PRML (GPRML) that are suppressed DC contents for matching to the response of perpendicular magnetic recording channel with a ring-head. In addition, DC-free encoding is considered to prevent low-frequency disturbances. The SNR performance is obtained by combining the various PRML channels with DC-free and non-DC-free codes during the normalized recording density increases from 2.5 to 3.5. The GPRML detections without using DC-free code get SNR gains more than 1dB compared to the conventional PRML systems at 10/sup -5/BER. We confirmed that the rate 127/136 DC-free coded GPRML systems show good performances compared with the 16/17 non-DC-free coded GPRML systems. In results, DC-free coded GPRML detections get gains about 1.4dB and 2.0dB at the density of 3.3 and 3.5, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.12C
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• pp.721-726
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• 2011

The compression performance of HEVC (high efficiency video coding) is improved 40%, compared to H.264/AVC. Since the existing 3D video CODEC is based on H.264/AVC or MPEG-2, we can improve the compression performance when we use the proposed stereoscopic video coding method based on HEVC. Since the stereoscopic video has the temporal and inter-view correlations, the videos of the left and right cameras encode together to improve the performance. Especially, we implemented the proposed technique using HM(HEVC test model) 3.4. To compare the performance of the proposed method, we only compare the right view video which is coded using the inter-view prediction. The proposed method which is considered inter-view correlation is improved the performance which BDBR reduce about 36.24% and BDPSNR increase approximately 1.19 dB compared to the separated-coding method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.9
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• pp.1635-1641
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• 2017

In this paper, a trellis-coded 3-dimensional (3-D) orthogonal frequency division multiplexing (OFDM) system is presented and its performance is analyzed. Here, a set-partitioning technique for trellis coding with respect to a 3-D signal constellation is also presented. We show theoretically that the proposed system, which exploits a trellis coding scheme with recursive systematic convolutional codes (RSC) of code rate R = 1/3 and 2/3, can improve symbol error rate (SER) up to 7.8 dB as compared with the uncoded OFDM system in an additive white Gaussian noise (AWGN) channel. Computer simulation confirms that the theoretical analysis of the proposed system is very accurate. It is, therefore, considered that the proposed trellis-coded 3-D OFDM system is well suited for the high quality digital transmission system without increase in the available bandwidth.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.326-329
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• 2009

This paper proposes a new video compression algorithm using an adaptive transform that is adjusted depending on the frequency contents of the input signals. The adaptive transform is based on the warped discrete cosine transform (WDCT) which is shown to provide better performance than the DCT at high bit rates, when applied to JPEG compression scheme [1, 2, 3]. The WDCT is applied to the video compression in this paper, as a new feature in the H.264/AVC. The proposed method shows the coding gain over the H.264/AVC at high bit rates. The coding gain is shown over the 35dB PSNR quality, and the gain increases as the bit rate increases. (about 1.0dB at 45dB PSNR quality at maximum)