• 제목/요약/키워드: Block quality

검색결과 1,212건 처리시간 0.031초

RTP/IP 기반의 네트워크 전송 환경에서 라그랑제 보간법을 이용한 에러 은닉 기법 (Error Concealment Algorithm Using Lagrange Interpolation For H.264/AVC)

  • 정학재;안도랑;이동욱
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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    • pp.161-163
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    • 2005
  • In this paper, we propose an efficient motion vector recovery algorithm for the new coding standard H.264, which makes use of the Lagrange interpolation formula. In H.264/AVC, a 16$\times$16 macroblock can be divided into different block shapes for motion estimation, and each block has its own motion vector. In the natural video the motion vector is likely to move in the same direction, hence the neighboring motion vectors are correlative. Because the motion vector in H.264 covers smaller area than previous coding standards, the correlation between neighboring motion vectors increases. We can use the Lagrange interpolation formula to constitute a polynomial that describes the motion tendency of motion vectors, and use this polynomial to recover the lost motion vector. The simulation result shows that our algorithm can efficiently improve the visual quality of the corrupted video.

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영상통신을 위한 새로운 프랙탈 부호화 기법 (A Novel Fractal Coding Method for Image Communication)

  • 김정일;김병천
    • 한국컴퓨터정보학회논문지
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    • 제3권3호
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    • pp.99-106
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    • 1998
  • 본 논문에서는 탐색영역 제한방식과 스케일링 방식을 이용하여 프랙탈 부호화시에걸리는 시간을 줄이는 방법으로서 영상통신을 위한 새로운 프랙탈 부호화 기법을 제안한다.먼저, 원영상을 스케일링 방식을 이용해 이분의 일과 사분의 일의 크기를 가지는 영상으로축소한다. 이어서, 이분의 일의 크기를 가지는 레인지 블럭들 중에 사분의 일의 크기를 가지는 도메인 블럭과 가장 유사한 블럭을 탐색영역 제한방식을 이용해 검색하게 된다. 실험 결과, 제안된 알고리즘은 Jacquin의 방법에 비해 복원된 영상의 화질은 약간 떨어졌으나, 압축율이 향상되고 부호화 시간을 크게 감소시킬 수 있었다.

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신경인성 방광 간호에 관한 고찰 (Literature Review of Neurogenic Bladder Care)

  • 김원옥
    • 기본간호학회지
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    • 제5권2호
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    • pp.225-236
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    • 1998
  • The literature review about bladder management method given to maintain and improve health of neurogenic bladder patients was done. Because the study of neurogenic bladder patients in nursing field is not enough, I tried to find report the study tendency through literature review, 1. There are five types of neurogenic bladder such as uninhibited neurogenic bladder, reflex neurogenic bladder, autonomous neurogenic bladder, sensory paralytic neurogenic bladder, and motor paralytic neurogenic bladder. 2. The accurate assessment of neurogenic bladder is done mainly through urodynamics and especially cystometrogram and urethrogram are used. 3. As the study of therapeutic management, the effect of Desmopressin, bladder auto-augmentation, incision of external urethral sphincter muscle, subarachnoid block and pudendal never block using phenol was studied. 4. For the study of general management, the effect of bladder training progam, intermittent catheterization and infection control has been studied but there has not been any obvious study in nursing field. Reviewed the study condition, it is necessary to develope bladder training program in order to increase life quality of neurogenic bladder patients.

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움직임 분류와 직접 탐색 패턴을 통한 고속 블록 움직임 추정 알고리즘 (A Fast Block Motion Estimation Algorithm Based On Motion Classification And Directional Search Patterns)

  • 박순철;후메라리사;최태선
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.903-904
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    • 2008
  • This paper suggests a simple scheme of block motion estimation in which the search pattern selection is based on the classification of motion content available in the spatio temporal neighboring blocks. The search area is divided into eight sectors and the search pattern selection is also based on the direction of predicted motion vector. Experimental results show that the proposed algorithm has achieved good predicted image quality measured in terms of PSNR and has very less computational complexity.

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SBC와 블럭 적응 양자화를 이용한 가정용 디지탈 VCR 영상 압축 알고리듬 (An Image Data Compression Algorithm for a Home-Use Digital VCR Using SBC with Block-Adaptive Quantization)

  • 김주희;서정태;박용철;이제형;윤대희
    • 전자공학회논문지B
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    • 제31B권9호
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    • pp.124-132
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    • 1994
  • An image data compression method for a digital VCR must satisfy special requirements such as high speed playback. various edting capabilities and error concealment to provide immunity to tape dropouts. Taking these requirements requirements into consideration, this paper proposes a new interframe subband coding algorithm for a digital VCR. In the proposed method, continuous input images are fist partitioned into four frequency bands. The lowest frequency subband is coded with 3-D block adaptive quantization that removes the level redundancy within each level. The other higher frequency subbands are coded by an intraframe coding method using the property of the human visual system. To keep reasonable image quality in high speed palyback, a segment forming method in the frequency domaing is also proposed Computer simulation results demonstrate that the proposed algorithm has the potential of achieving virtually lossless compression in normal play and produces an image with less mosaic errors in high speed play.

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사축식 Axial Piston Pump의 Rod 구동 메카니즘 해석 (The analysis of driving mechanism of rods in bent-axis-type axial piston pump)

  • 김종기;정재연
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1997년도 제26회 추계학술대회
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    • pp.76-85
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    • 1997
  • Recently, bent-axis-type axial piston pumps drived by rod being in extensively used in the world, because of simple design, lightweight, effective cost. So, to guarantee the quality of bent-axis-type axial piston pumps drived by rods, it is necessary to know chracteristics of the forces applied to rods and the driving mechanism of rods. But, as they perform both reciprocating and spinning motions, it is difficult to understand driving mechanism. In this paper, I explained the theoretical driving mechanisms of cylinder block drived by rods through geometric method and the characteristics of the forces applied to them.

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지각적으로 고화질을 보장하는 심층암층기술 (High Quality perceptual Steganographic Techiques)

  • 장기식;정창호;이상진;양일우
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 컴퓨터소사이어티 추계학술대회논문집
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    • pp.157-160
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    • 2003
  • Recently, several steganographic algorithms for two-color binary images have been proposed. In this paper, we propose a steganographic algorithm which embeds a secret message into bitmap images and palette-based images. To embed a message, the suggested algorithm divides a bitmap image into bit-plane images from LSB-plane to MSB-plane for each pixel, and considers each bit-plane image as a binary one. The algorithm splits each bit-plane image into m$\times$n blocks. and embeds a r-bit(r=[log$_2$(mn+1]-1) message into the block. And our schemes embed a message to every bit-plane from LSB to MSB to maximize the amount of embedded message and to minimize the degradation. The schemes change at most two pixels in each block. Therefore, the maximal color changes of the new algorithm are much smaller than other bit-plane embedding schemes' such as the substantial substitution schemes.

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세그멘트기법을 이용한 프랙탈 영상 부호화에 대한 연구 (A study On the Image Coding Based on the Segmented Fractal Coding)

  • 서주하;최황규;조철희
    • 산업기술연구
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    • 제15권
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    • pp.93-101
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    • 1995
  • Fractal coding is a promising method for image compression, but it has not lived up to its promise as low bit-rate image compression scheme. The existing algorithms for finding self-mapping contractive transforms are computationally expensive and offer a poor rate-quality tradeoff. In this paper, we propose a segment based fractal coding. We classify the range blocks into shade, midrange or edge blocks, and segment edge block along the edge. And we apply midrange coding scheme for each segment. Our experiments show that our method gives better rate-qualty trade of than current fractal block coding methods.

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New Design of Choice Sets for Choice-based Conjoint Analysis

  • Kim, Bu-Yong
    • 응용통계연구
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    • 제25권5호
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    • pp.847-857
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    • 2012
  • This article is concerned with choice-based conjoint analysis versus rating-based and ranking-based conjoint analysis. Choice-based conjoint analysis has a definite advantage in that the respondent's task of choosing the most preferred profile from several competing profiles adequately mimics consumer marketplace behavior. It is crucial to design the choice sets appropriate for the choice-based conjoint. Thus, this article suggests a new method to design the choice sets that are well-balanced. It augments the balanced incomplete block design and then obtains the dual design of the result to accommodate various numbers of profiles. In consequence, the choice sets designed by the new method have the desirable characteristics that each profile is presented to the same number of respondents, and pairs of any two distinct profiles occur together in the same number of choice sets. The balancing of the design increases the efficiency of the conjoint analysis. In addition, the pair-comparison scheme can improve the quality of data through the identification of contradictory responses.

인지 왜곡 척도를 사용한 프랙탈 영상 압축 (Fractal image compression with perceptual distortion measure)

  • 문용호;박기웅;손경식;김윤수;김재호
    • 한국통신학회논문지
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    • 제21권3호
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    • pp.587-599
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    • 1996
  • In general fractal imge compression, each range block is approximated by a contractive transform of the matching domain block under the mean squared error criterion. In this paper, a distortion measure reflecting the properties of human visual system is defined and applied to a fractal image compression. the perceptual distortion measure is obtained by multiplying the mean square error and the noise sensitivity modeled by using the background brightness and spatial masking. In order to compare the performance of the mean squared error and perceptual distortion measure, a simulation is carried out by using the 512*512 Lena and papper gray image. Compared to the results, 6%-10% compression ratio improvements under improvements under the same image quality are achieved in the perceptual distortion measure.

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