• 한국통신학회논문지
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• 제36권4C호
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• pp.207-216
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• 2011

움직임 보상 외삽 기법은 움직임 보상 보간 기법에 비해서 과거의 프레임만 사용하기 때문에 성능은 다소 떨어지지만, 전송 중에 손상된 프레임의 복원 및 프레임율 증가 뿐 아니라 분산 동영상 부호화 시스템의 부가 정보 생성에도 활용될 수 있다. 본 논문에서는 다양한 움직임 보상 외삽 기법의 성능을 평가하고 순방향과 역방향 움직임 추정을 함께 이용한 효율적인 움직임 보상 외삽 기법을 제안한다. 제안하는 기법은 순방향과 역방향 움직임 추정을 통해 두 개의 프레임을 생성하여 두 프레임의 화소값의 평균을 현재 프레임으로 한다. 모의 실험 결과 제안하는 기법이 기존의 기법에 비해서 블록 현상이 감소하고 우수한 PSNR 성능을 보임을 확인하였다.

• 한국정보통신학회논문지
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• 제12권7호
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• pp.1187-1192
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• 2008

본 논문은 적응적 탐색 영역과 새로운 3단계 탐색을 이용하는 고속 움직임 추정을 제안한다. 제안한 방법은 이웃 블록의 모션벡터로부터 현재 블록의 움직임를 예측하고, 예측된 움직임 정보를 이용하여 탐색 영역을 적응적으로 설정함으로써 움직임 보상 영상의 화질이 $0.43dB{\sim}2.19dB$ 향상되었다. 또한 새로운 3단계 탐색 패턴을 적용하여 블록 당 계산량을 기존의 방법에 비해 $1.3%{\sim}1.9%$ 감소시킴으로써 고속 움직임 추정이 가능함을 알 수 있었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권9호
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• pp.4587-4605
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• 2019

High Efficiency Video Coding (HEVC) suffers from high computational complexity due to its quad-tree structure in motion estimation (ME). This paper exposes an adaptive search range decision algorithm for accelerating HEVC integer-pel ME on GPU which estimates the optimal search range (SR) using a MAP (Maximum A Posteriori) estimator. There are three main contributions; First, we define the motion feature as the standard deviation of motion vector difference values in a CTU. Second, a MAP estimator is proposed, which theoretically estimates the motion feature of the current CTU using the motion feature of a temporally adjacent CTU and its SR without any data dependency. Thus, the SR for the current CTU is parallelly determined. Finally, the values of the prior distribution and the likelihood for each discretized motion feature are computed in advance and stored at a look-up table to further save the computational complexity. Experimental results show in conventional HEVC test sequences that the proposed algorithm can achieves high average time reductions without any subjective quality loss as well as with little BD-bitrate increase.

• 대한임베디드공학회논문지
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• 제7권5호
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• pp.285-290
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• 2012

In this paper, we propose a fast encoding algorithm for scalable video encoding without compromising coding performance. Through analysis on multiple motion estimation processes performed at the enhancement layer, we show redundant motion estimations and suggest the condition under which the redundant ones can efficiently be determined without additional memory. Based on the condition, the redundant motion estimation processes are excluded in the proposed algorithm. Simulation results show that the proposed algorithm is faster than the conventional fast encoding method without performance degradation and additional memory.

• 한국IT서비스학회지
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• 제2권2호
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• pp.111-119
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• 2003

In this paper, an efficient block matching algorithm which is based on the Block Sum Pyramid Algorithm (BSPA) is presented. The cost of BSPA[1] was reduced in the proposed algorithm by using l2 norm and partial distortion elimination technique. Motion estimation accuracy of the proposed algorithm is equal to that of BSPA. The efficiency of the proposed algorithm was verified by experimental results.

• 대한전기학회논문지:시스템및제어부문D
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• 제53권8호
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• pp.602-605
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• 2004

A novel motion vector re-estimation technique for transcoding into lower spatial resolution is proposed. This technique is based on the fact that the block matching error is proportional to the complexity of the reference block with Taylor series expansion. It is shown that the motion vectors re-estimated by the proposed method are closer to optimal ones and offer better quality than those of previous techniques.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.339-342
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• 2005

We present an efficient block-based motion estimation algorithm with motion analysis. The motion analysis determines a size of search pattern and a maximum repeated count of search pattern. In case of large movement in large image, we reduce search points and the local minimum which caused by low performance. The proposed algorithm employs with searching step of 2. The first step determines an initial search point with neighbor block vector and a size of initial search pattern. The second step determines a size of search pattern and a maximum repeated count with motion analysis. We improve motion prediction accuracy while reducing required computational complexity compared to other fast block-based motion estimation algorithms.

• Journal of Information Display
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• 제5권3호
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• pp.1-7
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• 2004

We developed a novel frame interpolation method to interpolate a frame between two successive original frames. Using this method, we are able to apply a double-rate driving method instead of an impulse driving method where a black frame is inserted between two successive original frames. The double-rate driving method enables amelioration of the motion blur of LCDs caused by the characteristics of human vision without reducing the luminosity of the whole screen. The image quality of the double-rate driving method was also found to be better than that of an impulse driving method using our motion picture simulator and an actual panel. Our initial model of our frame interpolation method consists of motion estimation with a maximum matching pixel count estimation function, an area segmentation technique, and motion compensation with variable segmentation threshold. Although salt and pepper noise remained in a portion of an object mainly due to inaccuracy of motion estimation, we verified the validity of our method and the possibility of improvement in hold-type motion blurring.

• 한국통신학회논문지
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• 제21권11호
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• pp.2776-2788
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• 1996

A new feature-based motion parameter estimation for arbitrary-shaped regions is proposed. Existing motion parameter estimation algorithms such as gradient-based algorithm require iterations that are very sensitive to initial values and which often converge to a local minimum. In this paper, the motion parameters of an object are obtained by solving a set of linear equations derived by the motion of salient feature points of the object. In order to estimate the displacement of the feature points, a new process called the "bi-directional correspondence scheme" is proposed to ensure the robjstness of correspondence. The proposed correspondence scheme iteratively selects the feature points and their corresponding points until unique one-to-one correspondence is established. Furthermore, initially obtained motion paramerters are refined using an iterative method to give a better performance. The proposed algorithm can be used for motion estimationin object-based image coder, and the experimental resuls show that the proposed method outperforms existing schemes schemes in estimating motion parameters of objects in image sequences.sequences.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.327-328
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• 2007

A contour shape matching based pixel motion estimation is proposed. The pixel motion information is very useful to compensate the motion artifact generated at the specific gray level contours in the moving image for subfield gray-scale display devices. In this motion estimation method, the gray level boundary contours are extracted from the input image. Then using contour shape matching, the most similar contour in next frame is found, and the contour is divided into segment unit. The pixel motion vector is estimated from the displacement of the each segment in the contour by segment matching. From this method, more precise motion vector can be estimated and this method is more robust to image motion with rotation or from illumination variations.