An overlapped block motion compensation for high quality motion picture coding

Nogaki, S.; Ohta, Masahiko

doi:10.1109/iscas.1992.229983

Cited by 64 publications

(39 citation statements)

References 9 publications

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“…Video coding has long exploited MH methods to improve video-coding quality [6]; common forms include subpixel-accurate MC [16], overlapped block MC [17], bidirectional MC (B-frames), and long-term-memory MC [18]. These techniques can be viewed as tradeoffs specific to a rate-limited environment; that is, these techniques impose specific structures on the hypotheses that form the ultimate prediction in order to limit the amount of additional motion-vector rate overhead entailed by multiple predictions of a single block.…”

Section: Mh Frame Prediction For Cs Reconstructionmentioning

confidence: 99%

Video Compressed Sensing with Multihypothesis

Tramel

Fowler

2011

2011 Data Compression Conference

107

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The compressed-sensing recovery of video sequences driven by multihypothesis predictions is considered. Specifically, multihypothesis predictions of the current frame are used to generate a residual in the domain of the compressed-sensing random projections. This residual being typically more compressible than the original frame leads to improved reconstruction quality. To appropriately weight the hypothesis predictions, a Tikhonov regularization to an ill-posed least-squares optimization is proposed. This method is shown to outperform both recovery of the frame independently of the others as well as recovery based on single-hypothesis prediction.

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Section: Mh Frame Prediction For Cs Reconstructionmentioning

confidence: 99%

Video Compressed Sensing with Multihypothesis

Tramel

Fowler

2011

2011 Data Compression Conference

107

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“…If we do not use the optimum filters (10), but some other suboptimum transfer function , we can combine (9), (17)- (19), and (20) to obtain (23), shown at the bottom of the page. Note that for and , we obtain the fundamental equations of motion-compensated prediction (1) and (2) as special cases of (23) and (21).…”

Section: Power Spectral Models For Inaccurate Motion Compensationmentioning

confidence: 99%

“…Since high-frequency components change rapidly, a high motion compensation accuracy is required. If motion compensation is inaccurate, then in (21) and (23) for high frequencies, and results in (21), and, assuming additionally that , then in (23). Obviously, the optimum filter is a low pass filter that removes high frequency components from that are too noisy or that change too rapidly for the given displacement error.…”

Section: Power Spectral Models For Inaccurate Motion Compensationmentioning

confidence: 99%

Efficiency analysis of multihypothesis motion-compensated prediction for video coding

Girod

2000

IEEE Trans. on Image Process.

185

128

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Abstract-Overlapped block motion compensation or B-frames are examples of multihypothesis motion compensation where several motion-compensated signals are superimposed to reduce the bit-rate of a video codec. This paper extends the wide-sense stationary theory of motion-compensated prediction (MCP) for hybrid video codecs to multihypothesis motion compensation. The power spectrum of the prediction error is related to the displacement error probability density functions (pdf's) of an arbitrary number of hypotheses in a closed-form expression. We then study the influence of motion compensation accuracy on the efficiency of multihypothesis motion compensation as well as the influence of the residual noise level and the gain from optimal combination of hypotheses. For the noise-free limiting case, doubling the number of (equally good) hypotheses can yield a gain of up to 1 2 bits/sample, while doubling the accuracy of motion compensation (such as going from integer-pel to 1 2-pel accuracy) can additionally reduce the bit-rate by up to 1 bit/sample independent of . For realistic noise levels, it is shown that the introduction of B-frames or overlapped block motion compensation can provide larger gains than doubling motion compensation accuracy. Spatial filtering of the motion-compensated candidate signals becomes less important if more hypotheses are combined. The critical accuracy beyond which the gain due to more accurate motion compensation is small moves to larger displacement error variances with increasing noise and increasing number of hypotheses . Hence, sub-pel accurate motion compensation becomes less important with multihypothesis MCP. The theoretical insights are confirmed by experimental results for overlapped block motion compensation, B-frames, and multiframe motion-compensated prediction with up to eight hypotheses from ten previous frames.

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“…Overlapped block MC (OBMC) recently has provided an effective extension of the conventional block MC (BMC) [12][13][14][15][16][17][18][19][20], in which blocks are overlapped with each other to reduce the blocking artifacts and residual errors in MC video. The complete estimate of the pixel value in the target block is decided as a linear combination of the previous estimate given by the MVs of the target block and the pixel values of neighboring blocks.…”

Section: Introductionmentioning

confidence: 99%

Block-Based Motion Estimation Using the Pixelwise Classification of the Motion Compensation Error

Kim¹

2012

SIPIJ

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In this paper, we propose block-based motion estimation (ME) algorithms based on the pixelwise classification of two different motion compensation (MC) errors: 1) displaced frame difference (DFD) and 2) brightness constraint constancy term (BCCT). Block-based ME has drawbacks such as unreliable motion vectors (MVs) and blocking artifacts, especially in object boundaries. The proposed block matching algorithm (BMA)-based methods attempt to reduce artifacts in object-boundary blocks caused by incorrect assumption of a single rigid (translational) motion. They yield more appropriate MVs in boundary blocks under the assumption that there exist up to three nonoverlapping regions with different motions. The proposed algorithms also reduce the blocking artifact in the conventional

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An overlapped block motion compensation for high quality motion picture coding

Cited by 64 publications

References 9 publications

Video Compressed Sensing with Multihypothesis

Video Compressed Sensing with Multihypothesis

Efficiency analysis of multihypothesis motion-compensated prediction for video coding

Block-Based Motion Estimation Using the Pixelwise Classification of the Motion Compensation Error

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