On Macroblock Partition for Motion Compensation

Hung, Edson M.; Queiroz, Ricardo L. de; Mukherjee, Debargha

doi:10.1109/icip.2006.312686

Cited by 48 publications

(16 citation statements)

References 3 publications

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“…In light of this problem, line-based segmentation schemes [7,8] that divide a code block using any arbitrary straight line segment that cuts across the code block have been proposed. There are two problems, however: i) the shape of the moving object may not follow a straight line, resulting in shape-mismatch; and ii) the computation required to search for a RD-optimal dividing line segment can be prohibitively expensive.…”

Section: Related Workmentioning

confidence: 99%

Arbitrarily shaped sub-block motion prediction in texture map compression using depth information

Daribo

Florêncio

Cheung

2012

2012 Picture Coding Symposium

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When transmitting the so-called "texture-plus-depth" video format, texture and depth maps from the same viewpoint exhibit high correlation. Coded bits from one map can then be used as side information to encode the other. In this paper, we propose to use the depth information to divide the corresponding block in texture map into arbitrarily shaped regions (sub-blocks) for separate motion estimation (ME) and motion compensation (MC). We implemented our proposed sub-block motion prediction (MP) method for texture map coding using depth information as a new coding mode (z-mode) in H.264. Nonetheless, in practical experiments one can observe either a misalignment between texture and depth edges, or an aliasing effect at the texture boundaries. To overcome this issue, z-mode offers two MC types: i) non-overlapping MC, and ii) overlapping MC. In the latter case, overlapped sub-blocks after ME are alpha-blended using a properly designed filter. Moreover, the MV of each sub-block in z-mode is predicted using a Laplacian-weighted average of MVs of neighboring blocks of similar depth. Experimental results show that using z-mode, coding performance of the texture map can be improved by up to 0.7dB compared to native H.264 implementation at high bitrate.

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Section: Related Workmentioning

confidence: 99%

Arbitrarily shaped sub-block motion prediction in texture map compression using depth information

Daribo

Florêncio

Cheung

2012

2012 Picture Coding Symposium

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“…A number of works have been focused on this goal. In [6,7], the GEO partitioning line is predicted based on a spatial edge detection. A refinement step is then applied around the detected spatial edges.…”

Section: Introductionmentioning

confidence: 99%

Fast encoding algorithms for geometry-adaptive block partitioning

Bordes

François

Thoreau

2011

2011 18th IEEE International Conference on Image Processing

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State-of-the-art video compression technologies, such as MPEG-4 AVC/H.264 or the new HEVC standard being developed by ISO MPEG and ITU-T VCEG, make use of tree-structured block partitioning for motion compensation. Such motion partitioning only captures horizontal and vertical motion boundaries. To better match actual motion frontiers, Geometry adaptive block partitioning (GEO) has been explored for several years. GEO enables splitting a block using non-horizontal or non-vertical line. Although noticeable coding efficiency gains can be obtained, GEO involves a significant increase of the number of modes to be tested with therefore a high impact on encoding complexity. This paper presents fast algorithms aiming at controlling the complexity while saving the coding efficiency gains of GEO. Experimental results are provided on top of the HEVC standard, demonstrating first the efficiency of the GEO tool. Simplified versions, offering noticeable complexity reduction with limited rate-distortion performance loss, are also demonstrated and compared.

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“…Further, searching for the most appropriate block sizes by evaluating the rate-distortion (RD) costs of possible coding modes is computationally expensive. Alternatively, line-based segmentation schemes [5,6] divide a code block using an arbitrary line segment that cuts across the code block. There are two problems to this approach: i) an object's boundary often is not a straight line, resulting in shape-mismatch; and ii) it is still computationally expensive to search for a RD-optimal dividing line segment.…”

Section: Related Workmentioning

confidence: 99%

Arithmetic edge coding for arbitrarily shaped sub-block motion prediction in depth video compression

Daribo

Cheung

Florêncio

2012

2012 19th IEEE International Conference on Image Processing

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Depth map compression is important for compact representation of 3D visual data in "texture-plus-depth" format, where texture and depth maps of multiple closely spaced viewpoints are encoded and transmitted. A decoder can then freely synthesize any chosen intermediate view via depth-image-based rendering (DIBR) using neighboring coded texture and depth maps as anchors. In this work, we leverage on the observation that "pixels of similar depth have similar motion" to efficiently encode depth video. Specifically, we divide a depth block containing two zones of distinct values (e.g., foreground and background) into two sub-blocks along the dividing edge before performing separate motion prediction. While doing such arbitrarily shaped sub-block motion prediction can lead to very small prediction residuals (resulting in few bits required to code them), it incurs an overhead to losslessly encode dividing edges for sub-block identification. To minimize this overhead, we first devise an edge prediction scheme based on linear regression to predict the next edge direction in a contiguous contour. From the predicted edge direction, we assign probabilities to each possible edge direction using the von Mises distribution, which are subsequently inputted to a conditional arithmetic codec for entropy coding. Experimental results show an average overall bitrate reduction of up to 30% over classical H.264 implementation.

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On Macroblock Partition for Motion Compensation

Cited by 48 publications

References 3 publications

Arbitrarily shaped sub-block motion prediction in texture map compression using depth information

Arbitrarily shaped sub-block motion prediction in texture map compression using depth information

Fast encoding algorithms for geometry-adaptive block partitioning

Arithmetic edge coding for arbitrarily shaped sub-block motion prediction in depth video compression

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