• Title/Summary/Keyword: image/video coding

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Zerotree Entropy Based Coding of Stereo Video Sequences

  • Thanapirom, S.;Fernando, W.A.C.;Edirisinghe, E.A.
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.908-911
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    • 2002
  • Over the past 30 years, many efficient 2D video coding techniques have been presented and developed from many research centers for commercialization. However, direct application of these monocular compression schemes is not optimal for stereo video coding. In this paper, we present a new technique for coding stereo video sequences based on Discrete Wavelet Transform (DWT). The proposed technique exploits Zerotree Entropy Coding (ZTE) that makes use of the wavelet block concept to achieve low bit rate stereo video coding. The one of two image streams, called main stream, is independently coded by modified MPEG-4 encoder and the other stream, called auxiliary stream, is coded by predicting from its corresponding image, its previous image or its follow image.

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Multithread video coding processor for the videophone (동영상 전화기용 다중 스레드 비디오 코딩 프로세서)

  • 김정민;홍석균;이일완;채수익
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.5
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    • pp.155-164
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    • 1996
  • The architecture of a programmable video codec IC is described that employs multiple vector processors in a single chip. The vector processors operate in parallel and communicate with one another through on-chip shared memories. A single scalar control processor schedules each vector processor independently to achieve real-tiem video coding with special vector instructions. With programmable interconnection buses, the proposed architecture performs multi-processing of tasks and data in video coding. Therefore, it can provide good parallelism as well as good programmability. especially, it can operate multithread video coding, which processes several independent image sequences simultaneously. We explain its scheduling, multithred video coding, and vector processor architectures. We implemented a prototype video codec with a 0.8um CMOS cell-based technology for the multi-standard videophone. This codec can execute video encoding and decoding simultaneously for the QCIF image at a frame rate of 30Hz.

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Lossless Inter-frame Video Coding using Extended JPEG2000

  • IMAIZUMI, Shoko;TAKAGI, Ayuko;KIYA, Hitoshi
    • Proceedings of the IEEK Conference
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    • 2002.07c
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    • pp.1803-1806
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    • 2002
  • This paper describes an effective technique for lossless inter-frame video coding sequences based on a JPEG2000 CODEC. This technique has diminished the compression rate for lossless video coding. In this proposed method, firstly a predicted image for an in- put image is generated by motion estimation(ME), and then a difference image between the input image and the predicted image is calculated, and finally the difference image becomes an input image to a JPEG2000 encoder for lossless coding. Simulation results show the effectiveness of this method.

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Distributed Coding Scheme for Multi-view Video through Efficient Side Information Generation

  • Yoo, Jihwan;Ko, Min Soo;Kwon, Soon Chul;Seo, Young-Ho;Kim, Dong-Wook;Yoo, Jisang
    • Journal of Electrical Engineering and Technology
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    • v.9 no.5
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    • pp.1762-1773
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    • 2014
  • In this paper, a distributed image coding scheme for multi-view video through an efficient generation of side information is proposed. A distributed video coding technique corrects the errors in the side information, which is generated with the original image, by using the channel coding technique at the decoder. Therefore, the more correct the generated side information is, the better the performance of distributed video coding. The proposed technique is to apply the distributed video coding schemes to the image coding for multi-view video. It generates side information by selectively and efficiently using both 3-dimensional warping based on the depth map with spatially adjacent frames and motion-compensated temporal interpolation with temporally adjacent frames. In this scheme the difference between the adjacent frames, the sizes of the motion vectors for the adjacent blocks, and the edge information are used as the selection criteria. From the experiments, it was observed that the quality of the side information generated by the proposed technique was improved by the average peak signal-to-noise ratio of 0.97dB than the one by motion-compensated temporal interpolation or 3-dimensional warping. The result from analyzing the rate-distortion curves revealed that the proposed scheme could reduce the bit-rate by 8.01% on average at the same peak signal-to-noise ratio value, compared to previous work.

Multiple Description Coding Using Directional Discrete Cosine Transform

  • Lama, Ramesh Kumar;Kwon, Goo-Rak
    • Journal of information and communication convergence engineering
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    • v.11 no.4
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    • pp.293-297
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    • 2013
  • Delivery of high quality video over a wide area network with large number of users poses great challenges for the video communication system. To ensure video quality, multiple descriptions have recently attracted various attention as a way of encoding and visual information delivery over wireless network. We propose a new efficient multiple description coding (MDC) technique. Quincunx lattice sub-sampling is used for generating multiple descriptions of an image. In this paper, we propose the application of a directional discrete cosine transform (DCT) to a sub-sampled quincunx lattice to create an MDC representation. On the decoder side, the image is decoded from the received side information. If all the descriptions arrive successfully, the image is reconstructed by combining the descriptions. However, if only one side description is received, decoding is executed using an interpolation process. The experimental results show that such the directional DCT can achieve a better coding gain as well as energy packing efficiency than the conventional DCT with re-alignment.

Evaluation of Coding Performance and Design of Spatial Multiplexer or 3D Endoscopic Image Processing (3D 내시경 영상처리를 위한 다중화기 설계와 부호화 성능평가)

  • Song, C.G.;Lee, S.M.;Lee, Y.M.;Kim, W.K.;Hwang, J.D.;Kim, J.H.;Lee, M.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.11
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    • pp.137-141
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    • 1997
  • In this study, in order to improve visualization and enhance the ability of the surgeon to perform delicate endoscopic surgery, three dimensional endoscopic system is designed. These 3D systems have our features of stereoendoscopic image processing: real time image capture and retrieve; presentation of left and right image on a single monitor; separable processing of the left and right eye images; coding of the 3D endoscopic video. For 3D endoscopic video coding, three approaches are presented based on interlaced picture structure, side-field format structure, and simulcast technique. Experimental results and performances comparisons are presented and analyzed or these approaches. Digital video coding techniques are presented or 3D endoscopic video sequences by means of an MPEG-2 video coding.

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Video Coding Using Wavelet Decomposition for Very Low Bit - rate Networks (초저속 전송 네트웍을 위한 웨이브릿 변환을 이용한 비디오 코딩)

  • Oh, Hwang-Seok;Lee, Heung-Kyu
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.10
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    • pp.2629-2639
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    • 1997
  • The video coding for very low bit-rate has recently received considerable attention, but the conventional coding schemes with block based transform suffer from the blocky effect for the constraints of limited bit-rate. In this paper, we present a video coding system based on wavelet transform and multiresolution motion estimation/compensation for very low bit-rate video. The proposed scheme uses the wavelet transform which is flexible to represent non-stationary image signals and adaptable to the human visual characteristics. The wavelet transformed coefficients are coded by various coding modes in accordance with the sum of absolute error after motion estimation/compensation in wavelet decomposed domain. And simple buffer control technique is applied to handle constant image quality. It is shown that the presented scheme has more acceptable image quality without blocky effects than conventional block based transform video coding.

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Key Management Scheme for Conditional Access Control in Scalable Video Coding (Scalable Video Coding 에서의 조건적 접근제어를 위한 키 관리 기법)

  • Won Yong-Geun;Bae Tae-Meon;Ro Yong-Man
    • Proceedings of the Korea Information Processing Society Conference
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    • 2006.05a
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    • pp.929-932
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    • 2006
  • 본 논문에서는 암호화된 Scalable Video Coding (SVC) 비트스트림에서의 조건적 접근제어을 위한 키 관리 기법을 제안한다. 스케일러블 비디오 코딩 기술은 한번 인코딩 후 비트스트림 추출을 통해 다양한 확장성(scalabbility)을 가지는 비디오를 생성 할 수 있는 기술로 확장하는 단위마다 다른 키로 암호화 하여 조건적 접근제어를 구성 할 수 있다. 그러나 기존의 조건적 접근제어 기술은 암호화 시 복수의 키가 필요하며 이는 키의 관리와 분배에 어려움을 준다. 이러한 문제를 해결하기 위해 본 논문에서는 기존의 스케일러블 코딩기법에서 조건적 접근제어를 위한 키 관리기법을 살펴보고 SVC 의 확장 구조에 맞는 키 관리 기법을 제안한다. 제안한 방법은 SVC 를 이용한 스트리밍 테스트베드에서 구현되어, 조건적 접근제어를 위한 키 관리기능의 유용성을 확인하였다.

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A Real-time Multiview Video Coding System using Fast Disparity Estimation

  • Bae, Kyung-Hoon;Woo, Byung-Kwang
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.7
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    • pp.37-42
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    • 2008
  • In this paper, a real-time multiview video coding system using fast disparity estimation is proposed. In the multiview encoder, adaptive disparity-motion estimation (DME) for an effective 3-dimensional (3D) processing are proposed. That is, by adaptively predicting the mutual correlation between stereo images in the key-frame using the proposed algorithm, the bandwidth of stereo input images can be compressed to the level of a conventional 2D image and a predicted image also can be effectively reconstructed using a reference image and adaptive disparity vectors. Also, in multiview decoder, intermediate view reconstruction (IVR) using adaptive disparity search algorithm (DSA) for real-time multiview video processing is proposed. The proposed IVR can reduce a processing time of disparity estimation by selecting adaptively disparity search range. Accordingly, the proposed multiview video coding system is able to increase the efficiency of the coding rate and improve the resolution.

TMS320C80에서의 subband decomposition을 이용한 image coding

  • 이원희;정진현
    • 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.

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