• Journal of Korea Multimedia Society
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• v.6 no.7
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• pp.1121-1130
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• 2003

This paper proposes a new motion estimation algorithm using the temporal continuity of motion. We set up a wide global search region (GSR), which basically corresponds to the search region of FSA, and 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. Then Motion estimation is only performed in the areas made by LSRs. Experimental results show that the proposed method can maintain visual qualifies with significant reductions of complexity by reducing search regions, when compared to the conventional FSA.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2A
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• pp.113-118
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• 2012

In this paper, we propose the removal of search point using motion vector correlation and distance between reference frames in H.264/AVC. We remove the search points in full search method and predictive motion vectors in enhanced predictive zonal search method. Since the probability that the reference frame far from the current frame is selected as the best reference frame is decreased, we apply the weighted average based on distance between the current and reference frame to determine the fianl search range. In general, the size of search range is smaller than initial search range. We reduce motion estimation time using the final search range in full search method. Also, the refinement process is adaptively applied to each reference frame. The proposed methods reduce the computational throughput of full search method by 57.13% and of enhanced predictive zonal search by 14.71% without visible performance degradation.

• Proceedings of the IEEK Conference
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• 2001.09a
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• pp.349-352
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• 2001

일반적인 동영상 압축 부호화 방법에서 시간적 중복 정보를 줄이기 위해 움직임 예측과 움직임 보상 방법을 이용한다. 웨이블릿 변환을 이용한 동영상 압축 부호화 기법 중에는 기존의 공간 영역에서의 움직임을 예측하는 대신에 웨이블릿 변환 영역에서 움직임을 예측하기도 한다. 이러한 방법은 움직임 예측 시간을 줄이는 장점이 있지만, 웨이블릿 변환에서 추림(Desimation)하는 과정에서 천이-변동 문제 (Shift-Variant Problem)를 일으켜 좋지 않은 성능을 나타낸다. 본 논문에서는 웨이블릿 영역에서의 다중 해상도 움직임 예측에서 천이-변동 문제를 해결하기 위한 새로운 움직임 예측과 움직임 보상 방법을 제안한다. 제안된 방법은, 기존의 공간 영역에서의 블록 정합 방법과 비교하여, 더 높은 화질을 나타낼 뿐 아니라, 주관적 화질에도 개선된 결과를 보인다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04b
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• pp.64-66
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• 2001

비디오 데이터는 미디어의 특성상 시간의 흐름에 따라 객체의 위치가 변하는 움직임 객체(Moving Object)를 가지며, 움직임 객체를 기반으로 비디오 데이트를 색인 및 검색하기 위해서는 적합한 시공간 표현 기법이 요구된다. 따라서 본 논문에서는 비디오 데이터가 지니는 움직임 객체의 움직임 경로(Trajectory)를 효율적으로 모델링하고 사용자에게 빠른 검색 결과를 제공할수 있는 근사 탐색(Approximation Search)이 가능한 새로운 시공간 표현 기법을 제안한다. 이는 사용자가 직접 스케치한 움직임 경로를 토대로 검색을 수행하는 내용 기반 검색과 움직임 객체의 일련의 움직임 경로들과 움직임 경로가 일어나는 위치 정보를 통해 얻어진 개념(의미)을 이용한 개념 기반 검색을 지원한다.

• Journal of Communication Design
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• v.38
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• pp.80-90
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• 2012

The purpose of this study is to determine the differences in eye-tracking, which is one of the emotional reactions of the autonomic nervous system, against various experimental stimuli that vary in terms of the movement attributes of graphic image. This experiment conducted an analysis of variance of the movement factors(n) in each movement attribute(speed, horizontality movement, verticality movement, diagonal movement). Dependent variables were the fixation starting time, the fixation dwell time, the whole fixation time from stimulus appearance, and the eye-tracking length. The result of eye-tracking against movement speed showed nonsignificant differences for each movement attribute. In the horizontality movement, the → movement was higher than the ← movement. In the verticality movement, the ↑ movement was higher than the ↓ movement. In the diagonal movement, there was not significant differences for each movement attributes.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.359-361
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• 2012

움직임 검출은 비디오 감시 시스템의 작업부하를 줄여주는 주요한 이슈가 되고 있다. 본 논문에서는 다양한 움직임 검출 알고리즘의 작업부하를 분석하고, 움직임 검출의 정확도와 작업부하를 고려한 경우의 최적 알고리즘을 도출한다. 비디오 감시 시스템에서 획득된 실제 데이터를 이용한 실험 결과, 움직임 프레임 비율이 낮은 환경의 비디오 감시 시스템에서는 차 프레임과 GMM을 이용하는 알고리즘이, 움직임 프레임 비율이 높은 환경에서는 GMM만을 이용하는 알고리즘이 정확도와 수행시간을 통합한 성능지수 관점에서 가장 효과적인 움직임 검출 솔루션이 될 수 있음을 확인하였다.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.6
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• pp.612-622
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• 2002

In this paper, we review temporal error concealment for video transport over unreliable networks, and a new approach for the recovery of lost or erroneous motion vection(MV)s by classifying the movements of neighboring blocks by their homogeneity is proposed. MVs of the neighboring blocks are classified according to the direction of MVs and a representative value for each class is determined to obtain the candidate MV set. By computing the distortion of the candidates, a MV with the minimum distortion is selected. Experimental results show that the proposed algorithm exhibits better performance in many cases than existing methods.

• 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

• The KIPS Transactions:PartB
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• v.16B no.2
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• pp.123-130
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• 2009

Motion estimation (ME) plays an important role in digital video compression. But it limits the performance of image quality and encoding speed and is computational demanding part of the encoder. To reduce computational time and maintain the image quality, integer pel and fractional pel ME methods are proposed in this paper. The proposed method for integer pel ME uses a hierarchical search strategy. This strategy method consists of symmetrical cross-X pattern, multi square grid pattern, diamond patterns. These search patterns places search points symmetrically and evenly that can cover the overall search area not to fall into the local minimum and to reduce the computational time. The proposed method for fractional pel uses full search pattern, center biased fractional pel search pattern and the proposed search pattern. According to block sizes, the proposed method for fractional pel decides the search pattern adaptively. Experiment results show that the speedup improvement of the proposed method over Unsymmetrical cross Multi Hexagon grid Search (UMHexagonS) and Full Search (FS) can be up to around $1.2{\sim}5.2$ times faster. Compared to image quality of FS, the proposed method shows an average PSNR drop of 0.01 dB while showing an average PSNR gain of 0.02 dB in comparison to that of UMHexagonS.

• Journal of Broadcast Engineering
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• v.7 no.3
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• pp.238-247
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• 2002

In this paper, we propose an object-based stereo sequence compression technique using disparity-motion vector relationship. The proposed method uses the coherence of motion vectors and disparity vectors in the left and right Image sequences. After two motion vectors and one disparity vector ate computed using FBMA(Fixed Block Matching Algorithm), the disparity vector of the current stereoscopic pall is computed by disparity-motion vector relationship with vectors which are previously estimated. Moreover, a vector regularization technique is applied in order to obtain reliable vectors. For an object-based coding. the object is defined and coded in terms of layers of VOP such as in MPEG-4. we present a method using disparity and motion vector relationship for extending two-frame compensation into three-frame compensation method for prediction coding of B-VOP. The proposed algorithm shows a high performance when comparing with a conventional method.