• Title/Summary/Keyword: DPCM

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Improved H.264/AVC Intra Lossless Compression Using Multiple Partition Prediction For $4{\times}4$ Intra Block ($4{\times}4$ 블록의 Multiple Partition 예측을 이용한 개선된 H.264/AVC 무손실 인트라 압축 방법)

  • Lee, Sang Heon;Cho, Nam Ik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2010.11a
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    • pp.295-297
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    • 2010
  • H.264/AVC 무손실 인트라 압축을 위하여 사용되는 픽셀 예측 방법은 Sample by Sample DPCM (SbS DPCM) 으로서 이 방법에서는 각각의 픽셀을 주변 픽셀로부터 예측하고 그 오차를 전송한다. 본 논문에서는 $4{\times}4$ 블록에 대한 Multiple Partition 예측과 SbS DPCM을 이용하여 H.264/AVC 의 무손실 인트라 압축 효율을 증가시키는 방법을 제안한다. 제안하는 방법은 각 $4{\times}4$ 블록을 $4{\times}4$, $4{\times}2$, $2{\times}4$, $2{\times}2$, $1{\times}1$ 크기의 sub-partition 을 가지는 다양한 partition 으로 예측한다. 이 때 각 sub-partition 들은 SbS DPCM을 이용하여 예측되고 이 때 사용하는 예측 방향의 개수는 예측 방향 정보량을 고려하여 sub-partition 크기에 따라 조절한다. 실험 결과에 의하면 제안하는 방법은 기존 H.264/AVC에 비하여 최대 17.02 %p, 평균 13.29 %p 의 압축율 개선을 보여주며 SbS DPCM만 사용하는 방법에 비하여 최대 4.74 %p, 평균 3.62 %p 정도의 압축율 개선을 보여준다.

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Voiced/Unvoiced/Silence Classification of Speech Signal by Level Crossing and DPCM (Level Crossing과 DPCM을 사용한 유성음/무성음/묵음의 분류)

  • Kim, Jin-Young;Sung, Koeng-Mo
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1615-1618
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    • 1987
  • This paper proposes new algorithm for classifying speech signal frame into voiced, unvoiced, silence frame, using the parameters extracted from time domain behavior of speech signal The prameters used in this paper are absolute magnitude, the sum of peaks lager than reference level (T-peak), the ratio of T-peak to absolute magnitude and the magnitude of signal outputs of DPCM. Using this parameters, speech signal is more easily classified into voiced/ unvoiced/silence frame.

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CUDA based Lossless Asynchronous Compression of Ultra High Definition Game Scenes using DPCM-GR (DPCM-GR 방식을 이용한 CUDA 기반 초고해상도 게임 영상 무손실 비동기 압축)

  • Kim, Youngsik
    • Journal of Korea Game Society
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    • v.14 no.6
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    • pp.59-68
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    • 2014
  • Memory bandwidth requirements of UHD (Ultra High Definition $4096{\times}2160$) game scenes have been much more increasing. This paper presents a lossless DPCM-GR based compression algorithm using CUDA for solving the memory bandwidth problem without sacrificing image quality, which is modified from DDPCM-GR [4] to support bit parallel pipelining. The memory bandwidth efficiency increases because of using the shared memory of CUDA. Various asynchronous transfer configurations which can overlap the kernel execution and data transfer between host and CUDA are implemented with the page-locked host memory. Experimental results show that the maximum 31.3 speedup is obtained according to CPU time. The maximum 30.3% decreases in the computation time among various configurations.

Improvement of Bit Rate by Removing the Repeated Sequences of Prediction Errors (예측오차 열의 중복성 제거에 의한 비트율 개선)

  • 김형철;조제황
    • The Journal of the Acoustical Society of Korea
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    • v.17 no.8
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    • pp.68-72
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    • 1998
  • 본 논문에서는 기존의 DPCM에 의한 압축방법보다 더 낮은 비트율을 갖는 압축방 법을 제안한다. 각 화소의 예측오차 값은 DPCM방법에 의해 양자화되고, 양자화된 예측오차 의 열은 예측오차의 학습된 열로 구성된 코드북과 비교된다. 비교과정은 벡터양자화 방법과 동일하고, 그 결과 코드북의 주소를 생성한다. 제안된 방법은 DPCM과 동일한 복원 영상의 화질을 보이지만, 더 낮은 비트율을 얻을 수 있다.

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An Edge Adaptive 1-Bit DPCM Image Coding (에지 적응 1-비트 DPCM 영상부호화)

  • 심영석;남상욱
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.7
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    • pp.819-825
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    • 1988
  • An 1-bit DPCM image coding method is presented. Our method is specially designed to reduce the slope overload which seems to be the major performance degradation factor in 1-bit DPCM. In the present algorithm, based on the classification of neighborhoods by its flatness, slope strength and direction, predictor and quantizer operate adaptively through switching action. Compared with some other methods by computer simulation, proposed method shows improved performance in image quality as well as in signal to noise ratio. This gain mainly comes from the reduced slope overload and seems large to compensate the increased complexity in prediction. As a post processing, Lee filter is used to reduce the granular noise subjectively annoying in flat region.

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A Study on an Embedded DPCM with Convolutional Coding (길쌈부호를 사용한 Embedded DPCM 방식에 관한 연구)

  • 임종수;이상곤;문상재
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.28A no.1
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    • pp.1-7
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    • 1991
  • Degradation of communication quality is due to transmission error rather than quantization noise when DPCM signal is transmitted over a heavily noise channel. The communication quality can be improved by employing an error correcting code to the DPCM signal transmission over such a channel. We considered both quantization noise and transmission error simultaneously in evaluating the signal to noise ratio. To efficiently improve the signal to noise ratio, we analyze the unequal symbol error probability of convolutional code, and encoded to more protect significant symbols from channel errors than least ones, so that the signal to noise ratio is improved. We derived related formulas and also made computer simulations.

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Design and Implementation of a Composite DPCM System for NTSC Color TV Signal (45Mb/s의 컬러 TV전송을 위한 기본적 DPCM시스템의 구성연구)

  • 박석현;이만섭;김재균
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.8 no.4
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    • pp.156-163
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    • 1983
  • A composite DPCM system is designed and implemented for the transmission of a NTSC color TV signal over a 44, 736Mbps channel. It is based on an intra-field fourth-order linear predictor and a nonlinear quantizer of five bits. The predictor preserves both the luminance and the chrominance components through one predictor. To accomodate the speed requirement for real time processing, mainly high speed ECL gates and memory devices are used in the hardware implementation. Experimental results show that this composite DPCM system can be applicable for a practical transmission of color TV signal with CATV quality.

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Applied of Integrated Optical Biosensor based on Combination of Photonic Crystal Micro-Cavity and Ring Resonator (광결정 공진기와 링 공진기의 공진특성 결합을 통한 바이오센서 응용)

  • Kim, Hong-Seung;Kim, Doo-Gun;Oh, Geum-Yoon;Lee, Tae-Kyeong;Choi, Young-Wan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.4
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    • pp.817-822
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    • 2011
  • We propose a novel ring structure based on the stadium-shaped ring resonator (SSRR) with dual photonic crystal microcavity (DPCM) for biosensor and analyzed the sensing characteristics. The Q-factor of the photonic crystal microcavity (PCM) can be significantly enhanced when the PCM or DPCM has the same resonance condition as the SSRR. The simulation results show that the Q-factor of the SRR with DPCM was increased by three times in comparison with single PCM structure. We also defined a mutual interference between two PCMs. Assuming a detectable spectral resolution of 10 picometers, a refractive index resolution of $3.03\times10-5$ can be measured on the SSRR-DPCM.

On the luminance adaptive DPCM coding of chrominance signals (명도신호를 이용한 색도신호의 부호화에 관한 연구)

  • 이해영;이만섭;김성대;김재균
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1984.10a
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    • pp.88-91
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    • 1984
  • In component coding, it si well known that a Luminance edge provides better masking of the noise added to chrominance signals. So we propose an adapive DPCM coding system which provides good performance in chromainance signals by using the effect of this masking.

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A new DPCM-based transmission scheme for flight data (차분펄스부호변조방식에 기반한 새로운 비행데이터 전송 기법)

  • Kang, Min-Woo;Moon, Yong-Ho
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.6
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    • pp.149-157
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    • 2011
  • In this paper, we propose a new DPCM-based transmission scheme for flight data. The amount of the flight data from LRU to MC has been increased due to the emergence and development of avionics systems and functions. It becomes a serious issue for satisfying the hard real-time processing required in the MC. In order to solve this problem, we observed the flight data produced by X-Plane simulator and discovered that the most flight data are moderately varied during flight. Based on this fact, a new data format is suggested by modifying that of ARINC-429 protocol in this paper. And the different value of the flight data is transmitted in the proposed scheme. The simulation results show that the proposed scheme achieves 20% data transfer gain compared to the ARINC-429 based transmission method.