• Title/Summary/Keyword: Encoding Schemes

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An Internal Pattern Run-Length Methodology for Slice Encoding

  • Lee, Lung-Jen;Tseng, Wang-Dauh;Lin, Rung-Bin
    • ETRI Journal
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    • v.33 no.3
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    • pp.374-381
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    • 2011
  • A simple and effective compression method is proposed for multiple-scan testing. For a given test set, each test pattern is compressed from the view of slices. An encoding table exploiting seven types of frequently-occurring pattern is used. Compression is then achieved by mapping slice data into codewords. The decompression logic is small and easy to implement. It is also applicable to schemes adopting a single-scan chain. Experimental results show this method can achieve good compression effect.

Modified Skyscraper Broadcasting Schemes for Periodic Broadcasting with VBR Video (VBR 리디오의 주기적 브로드캐스팅을 위한 수정 Skyscraper 브로드캐스팅 기법)

  • 이재동
    • Journal of Korea Multimedia Society
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    • v.5 no.5
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    • pp.571-581
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    • 2002
  • Many periodic broadcasting schemes for near VoD systems are proposed. Recently non-uniform segmentation schemes have been used to develop periodic broadcasting techniques for near VoD. These techniques give significant reductions in start-up latency as compared with more conventional uniform segmentation. However, all of these schemes assume that the videos are CBR-encoded. Since a CBR-encoded video has a target average tate than an VBR encoding, there is potential to obtain further Performance Improvements by using VBR videos. Unfortunately, however, the studies concerning broadcasting with VBR video ate rare and the existing techniques have the problem of virtual loss. In this paper, we modify Skyscraper Broadcasting Scheme for broadcasting with VBR videos which is a representative non-uniform segmentation scheme lot CBR videos. A VBR video can be transmitted at constant bit rate (CBR) by using prefetching. With this idea we propose Modified Skyscraper Broadcasting Schemes for VBR videos and make performance evaluation by simulation. We show that our schemes have a better performance than Skyscraper Broadcasting Scheme for CBR videos.

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Design of Asynchronous System Bus Wrappers based on a Hybrid Ternary Data Encoding Scheme (하이브리드 터너리 데이터 인코딩 기반의 비동기식 시스템 버스 래퍼 설계)

  • Lim, Young-Il;Lee, Je-Hoon;Lee, Seung-Sook;Cho, Kyoung-Rok
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.1
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    • pp.36-44
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    • 2007
  • This paper presented a hybrid ternary encoding scheme using 3-valued logic. It can adapt to the delay-insensitive(DI) model. We designed an asynchronous wrapper for the hybrid ternary encoding scheme to communicate with various asynchronous encoding schemes. It reduced about 50% of transmission lines and power consumption compared with the conventional 1-of-4 and ternary encoding scheme. The proposed wrappers were designed and simulated using the $0.18-{\mu}m$ standard CMOS technology. As a result, the asynchronous wrapper operated over 2 GHz communicating with a system bus. Moreover, the power dissipation of the system bus adapted the hybrid ternary encoding logic decreases 65%, 43%, and 36% of the dual-rail, 1-of-4, and ternary encoding scheme, respectively. The proposed data encoding scheme and the wrapper circuit can be useful for asynchronous high-speed and low-power asynchronous interface.

Serial Concatenation of Space-Time and Recursive Convolutional Codes

  • Ko, Young-Jo;Kim, Jung-Im
    • ETRI Journal
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    • v.25 no.2
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    • pp.144-147
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    • 2003
  • We propose a new serial concatenation scheme for space-time and recursive convolutional codes, in which a space-time code is used as the outer code and a single recursive convolutional code as the inner code. We discuss previously proposed serial concatenation schemes employing multiple inner codes and compare them with the new one. The proposed method and the previous one with joint decoding, both performing a combined decoding of the simultaneous output signals from multiple antennas, give a large performance gain over the separate decoding method. In decoding complexity, the new concatenation scheme has a lower complexity compared with the multiple encoding/joint decoding scheme due to the use of the single inner code. Simulation results for a communication system with two transmit and one receive antennas in a quasi-static Rayleigh fading channel show that the proposed scheme outperforms the previous schemes.

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Adaptive Scanning Method for Fine Granularity Scalable Video Coding

  • Park, Gwang-Hoon;Kim, Kyu-Heon
    • ETRI Journal
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    • v.26 no.4
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    • pp.332-343
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    • 2004
  • One of the recent and most significant technical properties can be expressed as "digital convergence," which is helping lead the technical paradigm into a ubiquitous environment. As an initial trial of realizing a ubiquitous environment, the convergence between broadcasting and telecommunication fields is now on the way, where it is required to develop a scalable video coding scheme for one-source and multi-use media. Traditional scalable video coding schemes have, however, limitations for higher stable picture quality especially on the region of interest. Therefore, this paper introduces an adaptive scanning method especially designed for a higher regional-stable picture quality under a ubiquitous video coding environment, which can improve the subjective quality of the decoded video by most-preferentially encoding, transmitting, and decoding the top-priority image information of the region of interest. Thus, the video can be more clearly visible to users. From various simulation results, the proposed scanning method in this paper can achieve an improved subjective picture quality far better than the widely used raster scan order in conventional video coding schemes, especially on the region of interest, and without a significant loss of quality in the left-over region.

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A Data Hiding Scheme for Grayscale Images Using a Square Function

  • Kwon, Hyejin;Kim, Haemun;Kim, Soonja
    • Journal of Korea Multimedia Society
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    • v.17 no.4
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    • pp.466-477
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    • 2014
  • Many image hiding schemes based on least significant bit (LSB) transformation have been proposed. One of the LSB-based image hiding schemes that employs diamond encoding was proposed in 2008. In this scheme, the binary secret data is converted into base n representation, and the converted secret data is concealed in the cover image. Here, we show that this scheme has two vulnerabilities: noticeable spots in the stego-image, i.e., a non-smooth embedding result, and inefficiency caused by rough re-adjustment of falling-off-boundary value and impractical base translation. Moreover, we propose a new scheme that is efficient and produces a smooth and high quality embedding result by restricting n to power of 2 and using a sophisticated re-adjustment procedure. Our experimental results show that our scheme yields high quality stego-images and is secure against RS detection attack.

Adaptive Linear Predictive Coding of Time-varying Images Using Multidimensional Recursive Least-squares Ladder Filters

  • Nam Man K.;Kim Woo Y.
    • Journal of the military operations research society of Korea
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    • v.13 no.1
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    • pp.1-18
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    • 1987
  • This paper presents several adaptive linear predictive coding techniques based upon extension of recursive ladder filters. A 2-D recursive ladder filter is extended to a 3-D case which can adaptively track the variation of both spatial and temporal changes of moving images. Using the 2-D/3-D ladder filter and a previous farme predictor, two types of adaptive predictor-control schemes are proposed in which the prediction error at each pel can be obtained at or close to a minimum level. We also investigate several modifications of the basic encoding methods. Performance of the 2-D/3-D ladder filters, their adaptive control schemes, and variations in coding methods are evaluated by computer simulations on a real sequence and compared to the results of motion compensation and frame differential coders. As a validity test of the ladder filters developed, the error signals for the different predictors are compared and evaluated.

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Fast Decoding Method of Distributed Video Based on Modeling of Parity Bit Requests (패리티 비트 요구량 모델링에 의한 분산 비디오의 고속 복호화 기법)

  • Kim, Man-Jae;Kim, Jin-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.11
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    • pp.2465-2473
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    • 2012
  • Recently, as one of low complexity video encoding methods, DVC (Distributed Video Coding) scheme has been actively studied. Most of DVC schemes exploit feedback channel to achieve better coding performances, however, this causes these schemes to have high decoding delay. In order to overcome these, this paper proposes a new fast DVC decoding method using parity-bit request model, which can be obtained by using bit-error rate, sent by encoder with motion vector, which is transmitted through feedback channel by decoder after generating side information. Through several simulations, it is shown that the proposed method improves greatly the decoding speed, compared to the conventional schemes.

On The performance of Coordinated Random Beamforming Schemes in A Two-Cell Symmetric Interference Channel (두 셀 대칭적 간섭 채널환경에서 협력적 불규칙 빔형성 방법의 성능에 대한 연구)

  • Yang, Jang-Hoon;Chae, Hyun-Jin;Kim, Yo-Han;Kim, Dong-Ku
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.4A
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    • pp.318-324
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    • 2011
  • In this paper, three coordinated random beamforming (CRBF) schemes are analyzed in a two-cell symmetric interference channel. A simple partial coordination of RBF with base station selection (BSS) is shown to achieve the same average sum rate performance of CRBF with joint encoding (JE). To improve the sum rate performance further, we also propose a transmission mode selection (TMS) between the BSS and JE which is shown to have additional sum rate gain for the large number of users. Simulation results verify the eectiveness of the proposed CRBF schemes and accuracy of the proposed analysis.

Channel Error Detwction and Concealment Technqiues for the MPEG-2 Video Standard (MPEG-2 동영상 표준방식에 대한 채널 오차의 검출 및 은폐 기법)

  • 김종원;박종욱;이상욱
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.10
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    • pp.2563-2578
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    • 1996
  • In this paper, channel error characteristics are investigated to alleviate the channel error propagation problem of the digital TV transmission systems. First, error propagation problems, which are mainly caused by the inter-frame dependancy and variable length coding of the MPEG-2 baseline encoder, are intensively analyzed. Next, existing channel resilient schemes are systematically classified into two kinds of schemes; one for the encoder and the other for the decoder. By comparing the performance and implementation cost, the encoder side schemes, such as error localization, layered coding, error resilience bit stream generation techniques, are described in this paper. Also, in an effort to consider the parcticality of the real transmission situation, an efficient error detection scheme for a decoder system is proposed by employing a priori information of the bit stream syntas, checking the encoding conditions at the encoder stage, and exploiting the statistics of the image itself. Finally, subsequent error concealment technique based on the DCT coefficient recovery algorithm is adopted to evaluate the performance of the proposed error resilience technique. The computer simulation results show that the quality of the received image is significantly improved when the bit error rate is as high as 10$^{-5}$ .

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