• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5C
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• pp.464-471
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• 2010

The demand for high quality of multimedia applications, which far surpasses the rapid evolution of transmission and storage technologies, makes better compression coding capabilities ever increasingly more important. In order to provide enhanced video coding performance, this paper proposes an efficient competition-based motion vector coding scheme. The proposed algorithm adaptively forms the motion vector predictors based on the contexts of scene characteristics such as camera motion and nearby motion vectors, providing more efficient candidate predictors than the previous competition-based motion vector coding schemes which resort to the fixed candidates optimized by extensive simulations. Up to 200% of compression gain was observed in the experimental results for the proposed scheme applied to the motion vector selection for skip mode processing.

• Journal of Korea Multimedia Society
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• v.7 no.8
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• pp.1025-1034
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• 2004

This paper proposes an adaptive motion estimation algorithm using the temporal continuity of motion. We set up a squared global search region (GSR), which basically corresponds to the search region of FSA, and non-squared adaptive local search regions (LSRs), the positions for which are predicted by the motion vectors of the temporal neighbor blocks, are constructed in the GSR. The previous frame blocks that possibly have effects on the current block are to be the temporal neighbor blocks. Because motion estimation is only performed in the areas made by LSRs, we can estimate motion more correctly and reduce processing time. Experimental results show that the proposed method can enhance visual qualities with significant reductions of complexity by reducing search regions, when compared to the conventional methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9A
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• pp.1411-1418
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• 1999

In this paper, we propose a fast motion estimation algorithm using motion prediction and neural network. Considering that the motion vectors have high spatial correlation, the motion vector of current block is predicted by those of neighboring blocks. The codebook of motion vector is designed by Kohonen self-organizing feature map(KSFM) learning algorithm which has a fast learning speed and 2-D adaptive chararteristics. Since the similar codevectors are closely located in the 2-D codebook the motion is progressively estimated from the predicted codevector in the codebook. Computer simulation results show that the proposed method has a good performance with reduced computational complexity.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.247-256
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• 2004

In this paper, we propose the prediction search algorithm for block matching using the temporal/spatial correlation of the video sequence and the renter-biased property of motion vectors The proposed algorithm determines the location of a better starting point for the search of an exact motion vector using the point of the smallest SAD(Sum of Absolute Difference) value by the predicted motion vector from the same block of the previous frame and the predictor candidate pint in each search region and the predicted motion vector from the neighbour blocks of the current frame. And the searching process after moving the starting point is processed a adaptive search pattern according to the magnitude of motion vector Simulation results show that PSNR(Peak-to-Signal Noise Ratio) values are improved up to the 0.75dB as depend on the video sequences and improved about 0.05∼0.34dB on an average except the FS (Full Search) algorithm.

• Journal of Korea Multimedia Society
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• v.13 no.7
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• pp.991-999
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• 2010

In this paper, we propose a fast motion estimation algorithm for video encoding. Conventional fast motion estimation algorithms have a serious problem of low prediction quality in some frames. However, full search based fast algorithms have low computational reduction ratio. In the paper, we propose an algorithm that significantly reduces unnecessary computations, while keeping prediction quality almost similar to that of the full search. The proposed algorithm uses distribution probability of motion vectors and adaptive search patterns and block matching criteria. By taking different search patterns and error criteria of block matching according to distribution probability of motion vectors, we can reduces only unnecessary computations efficiently. Our algorithm takes only 20~30% in computational amount and has decreased prediction quality about 0~0.02dB compared with the fast full search of the H.264 reference software. Our algorithm will be useful to real-time video coding applications using MPEG-2 or MPEG-4 AVC standards.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.67-70
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• 2009

H.264/AVC 동영상 표준은 기존의 동영상 표준과 비교했을 때 뛰어난 압축률을 보인다. 특히 세밀한 움직임 예측을 통해 영상을 효율적으로 압축하지만 움직임 예측은 H.264/AVC 동영상 표준의 높은 복잡도의 원인 중 하나이다. 따라서 H.264/AVC의 부호화 시간을 단축하기 위해서는 고속 움직임 추정 기법이 필수적이다. 일반적으로 영상 신호는 인접한 화면과 매크로블록 사이에서 상관관계가 높고 부호화하고자 하는 매크로블록의 움직임벡터는 인접한 매크로블록에서 결정된 최적의 움직임 벡터와 유사한 방향성을 가진다. 그러므로 고정된 탐색 영역의 크기를 이용하면 불필요한 영역까지 움직임 예측 과정이 수행되어 계산량이 증가한다. 본 논문에서는 영상의 공간적, 시간적 상관도를 이용하여 탐색 영역의 크기를 결정하는 방법을 제안한다. 인접하는 블록들의 움직임 벡터의 표준편차를 이용하여 움직임이 작은 영역에서는 작은 탐색 영역을 이용하여 움직임 예측을 수행하고 반대로 움직임이 큰 영역에서는 큰 탐색 영역을 이용하여 움직임 예측을 수행한다. 또한 현재 화면과 참조 화면의 거리차가 클수록 참조 화면으로 선택되는 확률이 낮다는 사실을 이용하여 적응적으로 탐색 영역의 크기를 조절한다. 제안한 방법은 기존의 전 영역 탐색 방법과 유사한 부호화 성능을 보이면서 움직임 예측 시간이 평균 약 58.93% 감소하는 것을 확인할 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.2C
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• pp.141-146
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• 2003

In this paper, we propose an adaptive search range decision algorithm for motion vector estimation in video coding. The performance of general motion estimation method in video coding mechanism is evaluated with respect to the motion vector accuracy and the complexity, which is trade-off. The proposed algorithm that plays as a role of pre-processing for motion vector estimation determines the motion search range by the local statistics of motion vector of neighboring blocks, resulting in more than 60(%) reduction of the computational cost without the loss of visual quality. Experimental results show the capability of the proposed algorithm.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.1-8
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• 2012

Video FRUC (Frame Rate Up Conversion) has been a technique of great interest due to its diversified applications in consumer electronics. Most advanced FRUC algorithms adopt a motion interpolation technique to determine the motion vector field of interpolated frames. But, in some applications, it is necessary to evaluate how well the MCI (Motion Compensated Interpolation) frame is reconstructed. For this aim, this paper proposes a distortion estimation for motion compensated interpolation frame using frame-adaptive distortion estimation. The proposed method is applied for the symmetric motion estimation and compensated scheme and then analyzed by three different approaches, that is, forward estimation, backward estimation and adaptive bi-directional estimation schemes. Through computer simulations, it is shown that the proposed bi-directional estimation method outperforms others and can be effectively applied for FRUC.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8A
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• pp.669-678
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• 2012

In this paper, we propose an efficient fast integer-pel motion estimation for H.264/AVC using local statistics of local motion vectors. Using neighboring motion vectors, we define a new statistical property that is used to determine a mode of motion search range of current block. In addition, an adaptive motion search range compensated method that is based on cumulative statistics of previous coded blocks is addressed to solve the problem of the statistical motion search range decision method. Experimental results show that proposed algorithm has the capability to reduce the computational cost over the other methods.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.159-161
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• 2017

In this paper, we propose an adaptive search range allocation algorithm for high-performance HEVC encoder and a hardware architecture suitable for the proposed algorithm. In order to improve the prediction performance, the existing motion vector is configured with the motion vectors of the neighboring blocks as prediction vector candidates, and a search range of a predetermined size is allocated using one motion vector having a minimum difference from the current motion vector. The proposed algorithm reduces the computation time by reducing the size of the search range by assigning the size of the search range to the rectangle and octagon type according to the structure of the motion vectors for the surrounding four blocks. Moreover, by using all four motion vectors, it is possible to predict more precisely. By realizing it in a form suitable for hardware, hardware area and computation time are effectively reduced.