• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.325-326
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• 2006

This paper proposes a new frame interpolation algorithm mainly designed for intra-mode blocks. In order to improve the accuracy of pixel interpolation, the new algorithm exploits two different interpolation modes for inter-mode blocks and intra-mode blocks, respectively. The use of the two modes reduces ghost artifacts but increases blocking artifacts between the blocks interpolated by different modes. To reduce blocking artifacts, this paper proposes an interpolation algorithm that attempts to isolate a fast moving object and interpolates such objects as the intra-mode while the remaining blocks are interpolated as the inter-mode. Simulation results show that the proposed algorithm improves subjective and objective quality of pictures by reducing ghost artifacts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.734-740
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• 2017

A frame rate up-conversion scheme is needed when moving pictures with a low frame rate is played on appliances with a high frame rate. Frame rate up-conversion methods interpolate the frame with two consecutive frames of the original source. This can be divided into the frame repetition method and motion estimation-based the frame interpolation one. Frame repetition has very low complexity, but it can yield jerky artifacts. The interpolation method based on a motion estimation and compensation can be divided into pixel or block interpolation methods. In the case of pixel interpolation, the interpolated frame was classified into four areas, which were interpolated using different methods. The block interpolation method has relatively low complexity, but it can yield blocking artifacts. The proposed method is the frame rate up-conversion method based on a block motion estimation and compensation using the linearity of motion. This method uses two previous frames and one next frame for motion estimation and compensation. The simulation results show that the proposed algorithm effectively enhances the objective quality, particularly in a high resolution image. In addition, the proposed method has similar or higher subjective quality than other conventional approaches.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.787-788
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• 2008

In this paper, we propose a Motion Estimation (ME) based on Frame Difference (FD) for frame interpolation in video sequence with luminance variation. Proposed algorithm uses limited blocks whose motion is predicted by FD for ME. The Block average of current and previous frame for the blocks which has no motion variation is used as interpolated block. In experiments, the proposed algorithm shows better performance than conventional algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.426-445
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• 2012

Conventional rate control (RC) schemes for H.264 video coding usually regulate output bit rate to match channel bandwidth by adjusting quantization parameter (QP) at fixed full frame rate, and the passive frame skipping to avoid buffer overflow usually occurs when scene changes or high motions exist in video sequences especially at low bit rate, which degrades spatial-temporal quality and causes jerky effect. In this paper, an active content adaptive frame skipping scheme is proposed instead of passive methods, which skips subjectively trivial frames by structural similarity (SSIM) measurement between the original frame and the interpolated frame via motion vector (MV) copy scheme. The saved bits from skipped frames are allocated to coded key ones to enhance their spatial quality, and the skipped frames are well recovered based on MV copy scheme from adjacent key ones at the decoder side to maintain constant frame rate. Experimental results show that the proposed active SSIM-based frameskip scheme acquires better and more consistent spatial-temporal quality both in objective (PSNR) and subjective (SSIM) sense with low complexity compared to classic fixed frame rate control method JVT-G012 and prior objective metric based frameskip method.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.47 no.4
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• pp.1-8
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• 2010

This paper proposes a new frame rate up-conversion method. First, the proposed triple frame-based bidirectional motion estimation method reduce block artifacts in the interpolated frame by solving the wrong motion estimation in the area with similar characteristics. Second, the proposed motion vector smoothing reduces outliers, which result in block artifacts, considering the spatio-temporal neighboring motion vectors. In the experiments, the proposed frame rate up-conversion method improves the average PSNR and SSIM by up to 4.337 dB and 0.089, respectively, compared to the existing methods.

• KIISE Transactions on Computing Practices
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• v.22 no.10
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• pp.532-536
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• 2016

Frame Rate Up Conversion (FRUC) generate interpolated frames between existing frames using motion estimation and motion compensation interpolation considering temporal redundancy. Falsely-estimated FRUC, however, can generate poor quality frames because FRUC typically uses blending-based interpolation method. As skipping an interpolating process between frames generate mis-estimated motion vectors, could improve Quality of Services of FRUC. In this Paper we analyze luminance histogram and motion vector consistency in frames generating poor quality interpolated frames. We conclude these features could help to be a clue in classifying the frames, which often result in the poor quality of FRUC results through the analysis and experiment.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2017.06a
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• pp.66-69
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• 2017

본 논문에서는 프레임율 향상 기법 (Frame Rate Up-Conversion, FRUC)에 사용되는 새로운 움직임 예측(motion estimation)알고리즘을 제시한다. 제안된 알고리즘은 단 방향 움직임 예측(unilateral motion estimation)에 의해 순방향 및 역방향의 움직임 벡터(motion vector)를 독립적으로 추정한다. 움직임 벡터를 찾은 후, weighted motion vector smoothing(WMVS)가 적용된다. 다음으로, 보간 프레임 (interpolated frame)의 관점에서 현재 블록의 인접 블록들의 모션 벡터들을 후보들로 사용하여 현재 블록과 가장 잘 일치하는 움직임 벡터를 찾는다. 그 후, 선택된 움직임 벡터를 현재 블록의 유도 움직임 벡터 (guidance motion vector)로 정한다. 그런 다음 motion vector shifting error 를 없애기 위해 motion vector refinement (MVR)가 진행된다. 마지막 단계에서는 각 움직임 벡터의 신뢰도를 계산하여 순방향 및 역방향 움직임 벡터 중 최종 움직임 벡터를 선택한다.

• Journal of the Optical Society of Korea
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• v.19 no.5
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• pp.537-543
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• 2015

Liquid crystal displays (LCDs) have slow responses, so motion blurs are often perceived in fast moving scenes. To reduce this motion blur, we propose a novel method of robust motion compensated frame interpolation (MCFI) based on bidirectional motion estimation (BME) and weight-overlapped block motion compensation (WOBMC) with variable block sizes. In most MCFI methods, a static block size is used, so some block artefacts and motion blurs are observed. However, the proposed method adjusts motion block sizes and search ranges by comparing matching scores, so the precise motion vectors can be estimated in accordance with motions. In the MCFI, overlapping ranges for WOBMC are also determined by adjusted block sizes, so the accurate MCFI can be performed. In the experimental results, the proposed method strongly reduced motion blurs arisen from large motions, and yielded interpolated images with high visual performance and peak signal-to-noise ratio (PSNR).

• Journal of Information Processing Systems
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• v.7 no.1
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• pp.103-110
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• 2011

In this paper, an adaptive motion vector smoothing scheme based on weighted vector median filtering is proposed in order to eliminate the motion outliers more effectively for improving the quality of side information in frame-based distributed video coding. We use a simple motion vector outlier reliability measure for each block in a motion compensated interpolated frame and apply weighted vector median filtering only to the blocks with unreliable motion vectors. Simulation results show that the proposed adaptive motion vector smoothing algorithm improves the quality of the side information significantly while maintaining low complexity at the encoder in frame-based distributed video coding.

• Journal of the korean Society of Automotive Engineers
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• v.12 no.2
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• pp.29-42
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• 1990

Three dimensional frame structures with such nonlinearities as large displacements, medium rotations, plastic hinges and local defects are efficiently analyzed by introducing the nonlinear rotational spring. Formulations are based on the incremental updated Lagrangian descriptions and the virtual work principle, Axial displacement and twisted angle in beam elements are interpolated linearly, while bending displacements are approximated by the Hermite polynomials. The modified are length method is used as a solution method. The moment-angle of rotation relationship obtained analytically or experimentally can be easily incorporated into the solution procedure. Several examples tested show that the present method can be used efficiently in analyzing nonlinear frame structures with plastic hinges or local defect.