• Title/Summary/Keyword: Variable block size

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시.공간 상관성을 이용한 움직임 추정 연구

  • Im, Gi-Yeong;Lee, Si-Hyeon
    • Proceedings of the Korea Information Processing Society Conference
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    • 2000.04a
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    • pp.858-863
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    • 2000
  • 동영상은 시간 및 공간적으로 많은 상관성을 지니고 있으며, 움직임추정 방법에서 움직임의 시 공간 상관성을 이용하면 정확한 움직임 추정과 성능 개선을 가져올 수 있다. 한편, Zafar와 Zhang은 웨이브릿 변환 영역에서 가변 블록 (variable block-size)을 이용한 다해상도 움직임 추정(multire-solution motion estimation) 기법을 제안하였다

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GNUnet improvement for anonymity supporting is large multimedia file (대형 멀티미디어 파일의 익명성 지원을 위한 수정 GNUnet)

  • Lee, Myeong-Hun;Jo, In-Jun
    • The Journal of Engineering Research
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    • v.7 no.1
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    • pp.89-97
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    • 2005
  • The GNUnet proposed a file encoding method by 1KB block size to support anonimity of file and decentralizes encoded block to peers through unstructed model. but, the encoding and block decentralizing method with 600~700MB large multimedia file appered two problems. First problem, it need addition R block and I block, which make about 4% of storage resource. Second problem, unstructed model added network load by broadcasting decentralizing method. The paper suggest variable encoding block size and structured model by block decentralizing solution. Suggested encoding method reduced block request supplementary block generation from 4% to 1%. and network load by proposal structured model sending answer through dedicated peer to decentralize block.

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Fast motion estimation scheme based on Successive Elimination Algorithm for applying to H.264 (H.264에 적용을 위한 SEA기반 고속 움직임 탐색 기법)

  • Lim Chan;Kim Young-Moon;Lee Jae-Eun;Kang Hyun-Soo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.42 no.2 s.302
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    • pp.151-160
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    • 2005
  • In this paper, we propose a new fast motion estimation algorithm based on successive elimination algorithm (SEA) which can dramatically reduce heavy complexity of the variable block size motion estimation in H.264 encoder. The proposed method applies the conventional SEA in the hierarchical manner to the seven block modes. That is, the proposed algorithm can remove the unnecessary computation of SAD by means of the process that the previous minimum SAD is compared to a current SAD for each mode which is obtained by accumulating sum norms or SAD of $4\times4$ blocks. As a result, we have tighter bound in the inequality between SAD and sum norm than in the ordinary SEA. If the basic size of the block is smaller than $4\times4$, the bound will become tighter but it also causes to increase computational complexity, specifically addition operations for sum norm. Compared with fast full search algorithm of JM of H.264, our algorithm saves 60 to $70\%$ of computation on average for several image sequences.

Enhanced Prediction for Low Complexity Near-lossless Compression (낮은 복잡도의 준무손실 압축을 위한 향상된 예측 기법)

  • Son, Ji Deok;Song, Byung Cheol
    • Journal of Broadcast Engineering
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    • v.19 no.2
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    • pp.227-239
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    • 2014
  • This paper proposes an enhance prediction for conventional near-lossless coder to effectively lower external memory bandwidth in image processing SoC. First, we utilize an already reconstructed green component as a base of predictor of the other color component because high correlation between RGB color components usually exists. Next, we can improve prediction performance by applying variable block size prediction. Lastly, we use minimum internal memory and improve a temporal prediction performance by using a template dictionary that is sampled in previous frame. Experimental results show that the proposed algorithm shows better performance than the previous works. Natural images have approximately 30% improvement in coding efficiency and CG images have 60% improvement on average.

Two-stage variable block-size multiresolution motion estiation in the wavelet transform domain (웨이브렛 변환영역에서의 2단계 가변 블록 다해상도 움직임 추정)

  • 김성만;이규원;정학진;박규태
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.7
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    • pp.1487-1504
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    • 1997
  • In this paper, the two-stage variable block-size multiresolution motion algorithm is proposed for an interframe coding scheme in the wavelet decomposition. An optimal bit allocagion between motion vectors and the prediction error in sense of minimizing the total bit rate is obtained by the proposed algorithm. The proposed algorithm consists of two stages for motion estimatation and only the first stage can be separated and run on its own. The first stage of the algorithm introduces a new method to give the lower bit rate of the displaced frame difference as well as a smooth motion field. In the second stage of the algorithm, the technique is introduced to have more accurate motion vectors in detailed areas, and to decrease the number of motion vectors in uniform areas. The algorithm aims at minimizin gthe total bit rate which is sum of the motion vectors and the displaced frame difference. The optimal bit allocation between motion vectors and displaced frame difference is accomplished by reducing the number of motion vectors in uniform areas and it is based on a botom-up construction of a quadtree. An entropy criterion aims at the control of merge operation. Simulation resuls show that the algorithm lends itself to the wavelet based image sequence coding and outperforms the conventional scheme by up to the maximum 0.28 bpp.

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Optimization of a Block Stacking Storage Model for a Single Product using (s, S) Inventory Policy ((s, S) 재고정책하에서 단일제품의 확률적 Block Stacking 저장모형의 최적화)

  • Yang, Moon-Hee;Chang, Kyung
    • Journal of Korean Institute of Industrial Engineers
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    • v.24 no.1
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    • pp.137-144
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    • 1998
  • Block stacking, which involves the storage of unit loads in stacks within storage rows, is typically used in traditional warehouses to achieve a high space utilization at a low investment cost. In this paper, assuming that the demand size from a customer is an i.i.d. random variable, we develop a probabilistic block stacking storage model and its algorithm for a singles product, which minimizes the time-overage floor space requirement under an (s, S) inventory policy and the violation of the FIFO lot rotation rule only in a single partially-occupied row.

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A Study on Motion Estimation Encoder Supporting Variable Block Size for H.264/AVC (H.264/AVC용 가변 블록 크기를 지원하는 움직임 추정 부호기의 연구)

  • Kim, Won-Sam;Sohn, Seung-Il
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.12 no.10
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    • pp.1845-1852
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    • 2008
  • The key elements of inter prediction are motion estimation(ME) and motion compensation(MC). Motion estimation is to find the optimum motion vectors, not only by using a distance criteria like the SAD, but also by taking into account the resulting number of 비트s in the 비트 stream. Motion compensation is compensate for movement of blocks of current frame. Inter-prediction Encoding is always the main bottleneck in high-quality streaming applications. Therefore, in real-time streaming applications, dedicated hardware for executing Inter-prediction is required. In this paper, we studied a motion estimator(ME) for H.264/AVC. The designed motion estimator is based on 2-D systolic array and it connects processing elements for fast SAD(Sum of Absolute Difference) calculation in parallel. By providing different path for the upper and lower lesion of each reference data and adjusting the input sequence, consecutive calculation for motion estimation is executed without pipeline stall. With data reuse technique, it reduces memory access, and there is no extra delay for finding optimal partitions and motion vectors. The motion estimator supports variable-block size and takes 328 cycles for macro-block calculation. The proposed architecture is local memory-free different from paper [6] using local memory. This motion estimation encoder can be applicable to real-time video processing.

Experimental Analysis of the AES Encryption Algorithm (AES 암호화 알고리즘의 실험적 분석)

  • Oh, Ju-Young;Suh, Jin-Hyung
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.3 no.2
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    • pp.58-63
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    • 2010
  • Cryptography is primarily a computationally intensive process. In this paper we expand AES scheme for analysis of computation time with four criteria, first is the compression of plain data, second is the variable size of block, third is the selectable round, fourth is the selective function of whole routine. We have tested our encryption scheme by c++ using MinGW GCC. Through extensive experimentations of our scheme we found that the optimal block size.

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Moving image coding with variablesize block based on the segmentation of motion vectors (움직임 벡터의 영역화에 의한 가변 블럭 동영상 부호화)

  • 김진태;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.3
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    • pp.469-480
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    • 1997
  • For moving image coding, the variable size of region coding based on local motion is more efficient than fixed size of region coding. It can be applied well to complex motions and is more stable for wide motions because images are segmented according to local motions. In this paper, new image coding method using the segmentation of motion vectors is proposed. First, motion vector field is smoothed by filtering and segmented by smoothed motion vectors. The region growing method is used for decomposition of regions, and merging of regions is decided by motion vector and prediction errors of the region. Edge of regions is excluded because of the correlation of image, and neighbor motion vectors are used evaluation of current block and construction of region. The results of computer simulation show the proposed method is superior than the existing methods in aspect of coding efficiency.

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Algorithm for Block Packing of Main Memory Allocation Problem (주기억장치 할당 문제의 블록 채우기 알고리즘)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.22 no.6
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    • pp.99-105
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    • 2022
  • This paper deals with the problem of appropriately allocating multiple processors arriving at the ready queue to the block in the user space of the main memory is divided into blocks of variable size at compilation time. The existing allocation methods, first fit(FF), best fit(BF), worst fit(WF), and next fit(NF) methods, had the disadvantage of waiting for a specific processor because they failed to allocate all processors arriving at the ready queue. The proposed algorithm in this paper is a simple block packing algorithm that allocates as many processors as possible to the largest block by sorting the size of the partitioned blocks(holes) and the size of the processor in the ready queue in descending order. The application of the proposed algorithm to nine benchmarking experimental data showed the performance of allocating all processors while having minimal internal fragment(IF) for all eight data except one data in which the weiting processor occurs due to partition errors.