• Title/Summary/Keyword: Concealment

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Error Concealment Using a Digital Watermarking Technique for Interframe Video Coding

  • Munadi, Khairul;Kurosaki, Masayuki;Kiya, Hitoshi
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.599-602
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    • 2002
  • A new approach of error concealment using a digital watermarking technique for interframe video coding is presented in this paper. In the proposed method, the most important feature of the reference frame is extracted. Then, this feature is embedded into the prediction error of current frame prior to transmission. Error concealment is achieved by means of recovering the erroneous reference frame using the embedded data before the reconstruction of current frame is performed. Simulation results demonstrated the effectiveness of the proposed method.

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Subblock Based Temporal Error Concealment of Intra Frame for MPEG-2 (서브 블록을 이용한 MPEG-2 인트라 프레임의 시간적 오류 은닉)

  • Ryu, Chul;Kim, Won-Rak
    • Proceedings of the KIEE Conference
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    • 2005.05a
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    • pp.167-169
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    • 2005
  • The occurrence of a single bit error in transmission bitstream leads to serious temporal and spatial errors. Because moving picture coding as MPEG-2 based on block coding algorithm uses variable length coding and motion compensation coding algorithm. In this paper, we propose algorithm to conceal occurred error of I-frames in transmission channel using data of the neighboring blocks in decoder. We divide a damaged macroblock of I-frame into four sub blocks and compose new macroblock using the neighboring blocks for each sub block. We estimate the block with minimum difference value through block matching with previous frame for new macroblocks and replace each estimated block with damaged sub block in the same position. Through simulation results, the proposed algorithm will be applied to a characteristic of moving with effect and shows better performance than conventional error concealment algorithms from visual and PSNR of view.

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Temporal Error Concealment Using Boundary Region Feature and Adaptive Block Matching (경계 영역 특성과 적응적 블록 정합을 이용한 시간적 오류 은닉)

  • Bae, Tae-Wuk;Kim, Seung-Jin;Kim, Tae-Su;Lee, Kun-Il
    • Proceedings of the KIEE Conference
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    • 2005.10b
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    • pp.12-14
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    • 2005
  • In this paper, we proposed an temporal error concealment (EC) using the proposed boundary matching method and the adaptive block matching method. The proposed boundary matching method improves the spatial correlation of the macroblocks (MBs) by reusing the pixels of the concealed MB to estimate a motion vector of a error MB. The adaptive block matching method inspects the horizontal edge and the vertical edge feature of a error MB surroundings, and it conceals the error MBs in reference to more stronger edge feature. This improves video quality by raising edge connection feature of the error MBs and the neighborhood MBs. In particular, we restore a lost MB as the unit of 8${\times}$16 block or 16${\times}$8 block by using edge feature from the surrounding macroblocks. Experimental results show that the proposed algorithm gives better results than the conventional algorithms from a subjective and an objective viewpoint.

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Improvement of Packet Loss Concealment Algorithm by Using state gain control and fixed codebook estimation (상태별 이득 제어 및 fixed codebook estimation을 이용한 G.729에서의 Packet Loss Concealment 알고리즘 개선)

  • Moon Kwang;Hahn Minsoo
    • Proceedings of the KSPS conference
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    • 2003.10a
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    • pp.109-112
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    • 2003
  • In real time packetized voice applications, missing frames is a major source of voice quality degradation. Thus packet loss concealment(PLC) algorithms are needed to guarantee the QoS of the VoIP. Still current speech codecs for VoIP work poor when consecutive packet losses are issued. In this paper, we proposed a new PLC algorithm for the G.729 codec. Our algorithm works better especially when the consecutive packet loss occurs mainly because it adopts an adaptive gain controller utilizing the number of missing packet information combined with a fixed codebook vector estimation algorithm and LPC bandwidth expansion.

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The Error Concealment Scheme Using DCT Based Image Coding for Mobile Network (무선 네트워크를 위한 DCT 기반의 오류 은닉 기법)

  • 양승준;박성찬;이귀상
    • Proceedings of the IEEK Conference
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    • 2000.11c
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    • pp.89-92
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    • 2000
  • The wireless network has bursty and high error rates. Due to the quite limited bandwidth in wireless networks, images are usually transmitted as a compressed version with VLC(variable length coding). Loss of coded data can affect a decoded image to a large extent, making concealment of errors caused by data loss an important issue. This paper presents a error concealment technique for DCT(Discrete Cosine Transform) based image coding. First, a method to estimate the missing DC coefficients of a JPEG coded image which is required for decoding the compressed image, is suggested and evaluated. Second, the missing data is interpolated by exploiting the probability of being nonzero and the correlation between adjacent blocks. In addition, since the these technique is computational efficient, it conserves system resources and power consumption, which are restrictive in mobile computers.

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Spatial Smoothing for Temporal Error Concealment (시간적 에러 은폐를 위한 공간적 스무딩)

  • 김동욱;김진태
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.594-597
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    • 2003
  • In this paper, we propose a new temporal error concealment method for recovery of video packet loss. Error concealment for each loss block is performed by temporal motion compensation and a smoothing operation of boundary pixels between the compensated block and its surrounding blocks. In the simulation results, performance improvement for the proposed technique is on the average 2 dB in comparison with the conventional technique.

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TEMPORAL ERROR CONCEALMENT ALGORITHM BASED ON ADAPTIVE SEACH RANGE AND MULTI-SIDE BOUNDARY INFORMATION FOR H.264/AVC

  • Kim, Myoung-Hoon;Jung, Soon-Hong;Kang, Beum-Joo;Sull, Sang-Hoon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.273-277
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    • 2009
  • A compressed video stream is very sensitive to transmission errors that may severely degrade the reconstructed image. Therefore, error resilience is an essential problem in video communications. In this paper, we propose novel temporal error concealment techniques for recovering lost or erroneously received macroblock (MB). To reduce the computational complexity, the proposed method adaptively determines the search range for each lost MB to find best matched block in the previous frame. And the original corrupted MB split into for $8{\times}8$ sub-MBs, and estimates motion vector (MV) of each sub-MB using its boundary information. Then the estimated MVs are utilized to reconstruct the damaged MB. In simulation results, the proposed method shows better performance than conventional methods in both aspects of PSNR.

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Disparity-based Error Concealment for Stereoscopic Images with Superpixel Segmentation

  • Zhang, Yizhang;Tang, Guijin;Liu, Xiaohua;Sun, Changming
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.9
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    • pp.4375-4388
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    • 2018
  • To solve the problem of transmission errors in stereoscopic images, this paper proposes a novel error concealment (EC) method using superpixel segmentation and adaptive disparity selection (SSADS). Our algorithm consists of two steps. The first step is disparity estimation for each pixel in a reference image. In this step, the numbers of superpixel segmentation labels of stereoscopic images are used as a new constraint for disparity matching to reduce the effect of mismatching. The second step is disparity selection for a lost block. In this step, a strategy based on boundary smoothness is proposed to adaptively select the optimal disparity which is used for error concealment. Experimental results demonstrate that compared with other methods, the proposed method has significant advantages in both objective and subjective quality assessment.

A Study of Psychopaths' Make-up Coordination Expressed on the Slasher Films (슬래셔 영화에 나타난 사이코패스의 분장 코디네이션 연구)

  • Chang, Mee-Sook
    • Fashion & Textile Research Journal
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    • v.10 no.3
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    • pp.399-406
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    • 2008
  • The purpose of this paper is to show how psychopaths' psychological factors are expressed on the characters' visual styles in the make-up coordination of slasher films. Psychopath is an ordinary person who has suffered some terrible trauma (humiliation, the death of a loved one, rape, psychological abuse), and features a disorder that consists of multiple components ranging on the emotional, interpersonal, and behavioral spectrum. Slasher films are sub genre of horror films that psychopathy characters, namely, Leather Face, Michael Myers, Jason Voorhees, Kenny Hampson, Harry Warden, Freddy Kruger and Billy kill the unfamiliar victims by cruel weapons with mercilessly. Their aesthetic characteristics of make-up coordination were shown in concealment, cruelty and suggestion. The concealment was presented by killers' masks, the cruelty was represented by their weapons, and the suggestion, especially space-time and status was depicted by their garments.

Frame Loss Concealment for Multi-View Video Sequences Based on Correspondence Matching Algorithm (일치점 정합 알고리즘에 기반한 다시점 비디오의 프레임 오류 은닉 방법)

  • Song, Kwan-Woong;Chung, Tae-Young;Oh, Yun-Je;Kim, Chang-Su
    • Proceedings of the IEEK Conference
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    • 2007.07a
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    • pp.255-256
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    • 2007
  • We propose a frame loss concealment algorithm for multi-view video sequences based on correspondence matching, which can hide the effects of frame losses efficiently. To achieve high PSNR performances, we employ a block error concealment scheme to refine the concealed results. Simulation results demonstrate that the proposed algorithm effectively protects the quality of reconstructed videos against transmission errors.

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