• Journal of Korea Multimedia Society
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• v.15 no.9
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• pp.1093-1101
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• 2012

Multi-view video is obtained by capturing one three-dimensional scene with many cameras at different positions. Multi-view video coding exploits inter-view correlations among pictures of neighboring views and temporal correlations among pictures of the same view. Multi-view video coding which uses many cameras requires a method to reduce the computational complexity. In this paper, we proposed an efficient prediction structure to improve performance of multi-view video coding. The proposed prediction structure exploits an average distance between the current picture and its reference pictures. The proposed prediction structure divides every GOP into several small groups to decide the maximum index of hierarchical B layer and the number of pictures of each B layer. Experimental results show that the proposed prediction structure shows good performance in image quality and bit-rates. When compared to the performance of hierarchical B pictures of Fraunhofer-HHI, the proposed prediction structure achieved 0.07~0.13 (dB) of PSNR gain and was down by 6.5(Kbps) in bitrate.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.4
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• pp.79-89
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• 2010

Recently, distributed video coding (DVC) has been actively studied for low complexity video encoder. The complexity of the encoder in DVC is much simpler than that of traditional video coding schemes such as H.264/AVC, but the complexity of the decoder in DVC increases. In this paper, we propose the Region-Of-Interest (ROI) based DVC with low decoding complexity. The proposed scheme uses the ROI, the region the motion of objects is quickly moving as the input of the Wyner-Ziv (WZ) encoder instead of the whole WZ frame. In this case, the complexity of encoder and decoder is reduced, and the bite rate decreases. Experimental results show that the proposed scheme obtain 0.95 dB as the maximum PSNR gain in Hall Monitor sequence and 1.87 dB in Salesman sequence. Moreover, the complexity of encoder and decoder in the proposed scheme is significantly reduced by 73.7% and 63.3% over the traditional DVC scheme, respectively. In addition, we employ the layered belief propagation (LBP) algorithm whose decoding convergence speed is 1.73 times faster than belief propagation algorithm as the Low-Density Parity-Check (LDPC) decoder for low decoding complexity.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1730-1733
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• 1997

In this paper, a realization of a subband coding with TMS320C80 is studied. TMS320C80 is a multi-media processor specially designed for an image process. A main topic of this paper, as mentioned above, is an application of TMS320C80 to subband coding. Subband coding is the coding that devides full image to several subbands and encodes each subband with different coding methods. As using that methods, good image compression can be obtained. First above all, goal of this paper deals with TMS320C80 in coding still image and useds it in expending it's application to 3-D video coding.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.11
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• pp.673-679
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• 2005

This Paper presents the 3D wavelet transformation based video compression system, which possesses the capability of progressive transmission by increasing resolution and increasing rate for multimedia applications. The 3D wavelet packet based video compression system removes the temporal correlation of the input sequences using the motion compensation filter and decomposes the spatio-temporal subband using the spatial wavelet packet transformation. The proposed system allocates the higher bit rate to the low frequency image of the 3D wavelet sequences and improves the 0.49dB PSNR performance of the reconstructed image in comparison with that of H.263. In addition to the limitation on the propagation of the motion compensation error by the 3D wavelet transformation, the proposed system progressively transmits the input sequence according to the resolution and rate scalability.

• Journal of Broadcast Engineering
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• v.22 no.3
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• pp.405-408
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• 2017

Based on the fact that high similarities exist between viewpoints of multi-view images, MV-HEVC achieves high encoding efficiency by performing conventional temporal direction prediction in a single viewpoint as well as inter-view prediction between viewpoints. In this paper, we propose to integrate SHVC and MVC (Multi-view Video Coding) to implement scalable multi-view video encoder using HEVC as a base layer. According to experimental results, it is verified that the BD-PSNR improvement reaches up to 1.5dB while reducing the BD-Bitrate by around 50~60%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.5
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• pp.1728-1743
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• 2021

Three-dimensional (3D) video scenes are complex and difficult to control, especially when scene switching occurs. In this paper, we propose two algorithms based on an incremental proportional-integral-derivative (PID) algorithm and a similarity analysis between views to improve the method of bit allocation for multi-view high efficiency video coding (MV-HEVC). Firstly, an incremental PID algorithm is introduced to control the buffer "liquid level" to reduce the negative impact on the target bit allocation of the view layer and frame layer owing to the fluctuation of the buffer "liquid level". Then, using the image similarity between views is used to establish, a bit allocation calculation model for the multi-view video main viewpoint and non-main viewpoint is established. Then, a bit allocation calculation method based on hierarchical B frames is proposed. Experimental simulation results verify that the algorithm ensures a smooth transition of image quality while increasing the coding efficiency, and the PSNR increases by 0.03 to 0.82dB while not significantly increasing the calculation complexity.

• ETRI Journal
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• v.36 no.2
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• pp.242-252
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• 2014

Since July of 2012, the 3D video extension of H.264/AVC has been under development to support the multi-view video plus depth format. In 3D video applications such as multi-view and free-view point applications, synthesized views are generated using coded texture video and coded depth video. Such synthesized views can be distorted by quantization noise and inaccuracy of 3D wrapping positions, thus it is important to improve their quality where possible. To achieve this, the relationship among the depth video, texture video, and synthesized view is investigated herein. Based on this investigation, an edge noise suppression filtering process to preserve the edges of the depth video and a method based on a total variation approach to maximum a posteriori probability estimates for reducing the quantization noise of the coded texture video. The experiment results show that the proposed methods improve the peak signal-to-noise ratio and visual quality of a synthesized view compared to a synthesized view without post processing methods.

• Journal of Broadcast Engineering
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• v.16 no.3
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• pp.510-519
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• 2011

Intra mode decision is a useful coding tool in Distributed Video Coding (DVC) for improving DVC coding efficiency for video sequences having fast motion. A major limitation associated with the existing intra mode decision methods, however, is that its efficiency highly depends on user-specified thresholds or modeling parameters. This paper proposes an entropy-based method to address this problem. The probabilities of intra and Wyner?Ziv (WZ) modes are determined firstly by examining correlation of pixels in spatial and temporal directions. Based on these probabilities, entropy of the intra and the WZ modes are computed. A comparison based on the entropy values decides a coding mode between intra coding and WZ coding without relying on any user-specified thresholds or modeling parameters. Experimental results show its superior rate-distortion performance of improvements of PSNR up to 2 dB against a conventional Wyner?Ziv coding without intra mode decision. Furthermore, since the proposed method does not require any thresholds or modeling parameters from users, it is very attractive for real life applications.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.433-436
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• 2003

In this paper, the efficient motion estimation and compensation method for 3 dimensional wavelet transform is proposed. Recently, since the compression performance and scalable functionality are provided by wavelet transform, many researches have been carried out for applying to the video compression. For the temporal filtering, motion estimation and compensation techniques are used, but the unconnected pixels, which are produced by motion compensation result into the degradation of coding performance and quality of the picture. For the efficient motion compensated temporal filtering by reducing the number of these unconnected pixels, we propose the variable block size motion estimation and compensation method. Also we propose a method that determines the block size using rate-distortion optimization technique according to the local characteristics of the frame. The simulation results show the improved performances than the MPEG-4 scalable coding methods and the 3 dimensional wavelet coding methods using fixed block size motion estimation and compensation.

• Journal of Broadcast Engineering
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• v.9 no.3
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• pp.214-224
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• 2004

In this paper, an adaptive spatio-temporal predictive coding based on the H.264 is proposed for 3D immersive media encoding, such as 3D image processing, 3DTV, and 3D videoconferencing. First, we propose a spatio-temporal predictive coding using the same view and inter-view images for the two TPPP, IBBP GOP (group of picture) structures 4hat are different from the conventional simulcast method. Second, an 2D inter-view direct mode for the efficient prediction is proposed when the proposed spatio-temporal prediction uses the IBBP structure. The 2D inter-view direct mode is applied when the temporal direct mode in B(hi-Predictive) picture of the H.264 refers to an inter-view image, since the current temporal direct mode in the H.264 standard could no: be applied to the inter-view image. The proposed method is compared to the conventional simulcast method in terms of PSNR (peak signal to noise ratio) for the various 3D test video sequences. The proposed method shows better PSNR results than the conventional simulcast mode.