A novel depth motion vector coding exploiting spatial and inter-component clustering tendency
- Authors: Shahriyar, Shampa , Murshed, Manzur , Ali, Mortuza , Paul, Manoranjan
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: Visual Communications and Image Processing, VCIP 2015; Singapore; 13th-16th December 2015 p. 1-4
- Relation: http://purl.org/au-research/grants/arc/DP130103670
- Full Text: false
- Reviewed:
- Description: Motion vectors of depth-maps in multiview and free-viewpoint videos exhibit strong spatial as well as inter-component clustering tendency. This paper presents a novel coding technique that first compresses the multidimensional bitmaps of macroblock mode and then encodes only the non-zero components of motion vectors. The bitmaps are partitioned into disjoint cuboids using binary tree based decomposition so that the 0's and 1's are either highly polarized or further sub-partitioning is unlikely to achieve any compression. Each cuboid is entropy-coded as a unit using binary arithmetic coding. This technique is capable of exploiting the spatial and inter-component correlations efficiently without the restriction of scanning the bitmap in any specific linear order as needed by run-length coding. As encoding of non-zero component values no longer requires denoting the zero value, further compression efficiency is achieved. Experimental results on standard multiview test video sequences have comprehensively demonstrated the superiority of the proposed technique, achieving overall coding gain against the state-of-the-art in the range [22%, 54%] and on average 38%. © 2015 IEEE.
- Description: 2015 Visual Communications and Image Processing, VCIP 2015
Disparity-adjusted 3D multi-view video coding with dynamic background modelling
- Authors: Paul, Manoranjan , Evans, Christopher , Murshed, Manzur
- Date: 2013
- Type: Text , Conference paper
- Relation: Proceedings of IEEE International Conference on Image Processing (ICIP 2013). 15th-18th Sept, Melbourne, Vic. p.1719-1723
- Full Text: false
- Reviewed:
- Description: Capturing a scene using multiple cameras from different angles is expected to provide the necessary interactivity in the 3D space to satisfy end-users' demands for observing objects and actions from different angles and depths. Existing multiview video coding (MVC) technologies are not sufficiently agile to exploit the interactivity and inefficient in terms of image quality and computational time. In this paper a novel technique is proposed using disparity-adjusted 3D MVC (DA-3D-MVC) with 3D motion estimation (ME) and 3D coding to overcome the problems. In the proposed scheme, a 3D frame is formed using the same temporal frames of all disparity-adjusted views and ME is carried out for the current 3D macroblock using the immediate previous 3D frame as a reference frame. Then, 3D coding technique is used for better compression. As all the same temporal position frames of all views are encoded at the same time, the proposed scheme provides better interactivity and reduced computational time compared to the H.264/MVC. To improve the rate-distortion (RD) performance of the proposed technique, an additional reference frame comprising dynamic background is also used. Experimental results reveal that the proposed scheme outperforms the H.264/MVC in terms of RD performance, computational time, and interactivity.
Exploiting spatial smoothness to recover undecoded coefficients for transform domain distributed video coding
- Authors: Ali, Mortuza , Murshed, Manzur
- Date: 2013
- Type: Text , Conference paper
- Relation: IEEE International Conference on Image Processing; Melbourne, Australia; 15th-18th September 2013, p. 1782-1786
- Relation: http://purl.org/au-research/grants/arc/DP1095487
- Full Text: false
- Reviewed:
- Description: In a transform domain distributed video coding scheme, the correlation between the current encoding unit, e.g. block and slice, and the corresponding side-information is modeled using a virtual channel. This correlation model is then used for rate allocation, quantization, and Wyner-Ziv coding. Since the encoder can only have an estimate of the correlation instead of the exact knowledge of the side-information, the decoder will fail to recover the quantized transformed coeffi- cients with a nonzero probability. In this paper, we propose to integrate a scheme at the decoder to recover the undecoded coefficients using the spatial smoothness property of individual video frames. Simulation results demonstrated that, at different decoding failure probabilities, a transformed coeffi- cient recovery scheme can significantly improve the quality of videos in terms of both PSNR and SSIM.
- Description: In a transform domain distributed video coding scheme, the correlation between the current encoding unit, e.g. block and slice, and the corresponding side-information is modeled using a virtual channel. This correlation model is then used for rate allocation, quantization, and Wyner-Ziv coding. Since the encoder can only have an estimate of the correlation instead of the exact knowledge of the side-information, the decoder will fail to recover the quantized transformed coeffi- cients with a nonzero probability. In this paper, we propose to integrate a scheme at the decoder to recover the undecoded coefficients using the spatial smoothness property of individual video frames. Simulation results demonstrated that, at different decoding failure probabilities, a transformed coeffi- cient recovery scheme can significantly improve the quality of videos in terms of both PSNR and SSIM