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Compressing the Laplacian Pyramid
"... The Laplacian pyramid (LP) is one of the earliest examples of multiscale representation of visual data. It is well known that an LP is overcomplete or redundant by construction, and has lower compression efficiency compared to critical representations such as wavelets and subband coding. In this pa ..."
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The Laplacian pyramid (LP) is one of the earliest examples of multiscale representation of visual data. It is well known that an LP is overcomplete or redundant by construction, and has lower compression efficiency compared to critical representations such as wavelets and subband coding. In this paper, we propose to improve the rate-distortion (R-D) performance of the LP through critical representation. We consider an LP with biorthogonal decimation and interpolation filters, and show that the detail signals lie in lower-dimensional subspaces. This allows them to be represented using fewer coefficients than the original spatial representations. We derive orthogonal bases for these subspaces and represent the detail signals in terms of their projections onto these bases. Simulation results suggest that higher compression ratios can be achieved with the critical representation than with the standard LP with usual or dual frame based reconstructions.
Spatially Scalable Video Coding For HEVC
"... Abstract—Spatially scalable video coding (SSVC) provides an efficient way to transmit one video at different resolutions. Based on the emerging High Efficiency Video Coding (HEVC), we propose an SSVC scheme to support both single-loop (SL) and multiloop (ML) solutions by enabling different interlaye ..."
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Abstract—Spatially scalable video coding (SSVC) provides an efficient way to transmit one video at different resolutions. Based on the emerging High Efficiency Video Coding (HEVC), we propose an SSVC scheme to support both single-loop (SL) and multiloop (ML) solutions by enabling different interlayer prediction mechanisms. Specifically, we employ two interlayer prediction modes: quadtree-based prediction mode (Q-mode) and learning-based prediction mode (L-mode). The Q-mode is investigated to exploit the interlayer redundancy based on the quadtree coding structure of HEVC. Due to the high correlation between layers, Q-mode utilizes the coded information from the base layer quadtree, including coding unit split, prediction unit partition, motion information, and partial texture information of transform unit, to predict the enhancement layer quadtree. By enabling Q-mode, we provide a basic SL solution for low complexity applications. Besides the correlation explored in Q-mode, we employ an extra L-mode to further improve the coding performance. In L-mode, the temporal-spatial correlation is exploited simultaneously by visual patch-based learning and mapping at pixel level. This helps us achieve more accurate prediction signals based on the coarse base layer reconstruction within an ML structure. Experimental results show the effectiveness of our SSVC scheme compared with the simulcast case and other HEVC-based SSVC schemes. Index Terms—High Efficiency Video Coding (HEVC), learningbased approach, scalable video coding (SVC).
LIFTING-BASED LAPLACIAN PYRAMID RECONSTRUCTION SCHEMES
"... Laplacian Pyramid (LP) provides a redundant signal representation and can be characterized as an oversampled filter bank (FB). In this paper, a generic lifting-based parameterization reconstruction algorithm is proposed to characterize all LP synthesis banks that can satisfy the perfect reconstructi ..."
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Laplacian Pyramid (LP) provides a redundant signal representation and can be characterized as an oversampled filter bank (FB). In this paper, a generic lifting-based parameterization reconstruction algorithm is proposed to characterize all LP synthesis banks that can satisfy the perfect reconstruction property. Two typical lifting-based LP reconstruction schemes are then derived from this general representation. The first scheme presents the dual frame LP reconstruction and its closed-form solutions for any LP filters. The second LP reconstruction scheme leads to an efficient FB, which demonstrates improvements over the usual LP reconstruction in the presence of noise. Index Terms — Laplacian pyramid, lifting, oversampled filter bank, dual frame 1.
Representing Laplacian Pyramids with varying Amount of Redundancy
- EUSIPCO 2006, Italy,2006 [8] Peter J Burt, Edward H Adelson, “ The Laplacian Pyramid as a Compact Image Code”, IEEE Trans on Communications,pp 532-540, vol.Com-31, No3
, 1983
"... The Laplacian pyramid (LP) is a useful tool for obtaining spa-tially scalable representations of visual signals such as image and video. However, the LP is overcomplete or redundant and has lower compression efficiency compared to critical representations such as wavelets and subband coding. In this ..."
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Cited by 1 (0 self)
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The Laplacian pyramid (LP) is a useful tool for obtaining spa-tially scalable representations of visual signals such as image and video. However, the LP is overcomplete or redundant and has lower compression efficiency compared to critical representations such as wavelets and subband coding. In this paper, we propose to improve the rate-distortion (R-D) performance of the LP by varying its re-dundancy through decimation of the detail signals. We present two reconstruction algorithms based on the frame theory and the cod-ing theory, and then show them to be equivalent. Simulation results with various standard test images suggest that, using suitable quan-tization parameters, it is possible to have better R-D performance over the usual or the dual frame based reconstruction. 1.
CLASSIFIED PATCH LEARNING FOR SPATIALLY SCALABLE VIDEO CODING
"... This paper proposes an advanced spatially scalable video coding approach that exploits the inter layer correlation between different resolution layers by classified patch learning. The novelty of our proposed scheme is twofold. First, the correlation between low and high resolution frames is explore ..."
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This paper proposes an advanced spatially scalable video coding approach that exploits the inter layer correlation between different resolution layers by classified patch learning. The novelty of our proposed scheme is twofold. First, the correlation between low and high resolution frames is explored at patch level with regard to image features. Patches extracted from the previous coded frame are classified into structural and textural sets according to the gradient information. Then the inter layer correlation is separately studied for the two sets, resulting in two databases containing pairs of patches at different resolutions. Second, our proposed patch-based compensation manages to simultaneously exploit the spatial and temporal redundancies without overhead bit for motion. Based on the two databases, a high resolution prediction is derived from the current low resolution reconstruction at structural and textural regions, respectively. Experimental results show that our proposed approach improves the performance of H.264/MPEG spatially scalable coding up to 1.9dB and significantly enhances the subjective quality, especially at low bit rates. Index Terms — Scalable video coding, spatially scalable, inter layer correlation, classified patch learning
FRACTIONAL COMPENSATION FOR SPATIAL SCALABLE VIDEO CODING
"... This paper proposes a novel fractional compensation approach for spatial scalable video coding. It simultaneously exploits inter layer correlation and intra layer correlation by learning-based mapping. Instead of using an enhancement layer reconstruction as an entire reference, a set of reference pa ..."
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This paper proposes a novel fractional compensation approach for spatial scalable video coding. It simultaneously exploits inter layer correlation and intra layer correlation by learning-based mapping. Instead of using an enhancement layer reconstruction as an entire reference, a set of reference pairs are generated from high-frequency components of both base layer and enhancement layer reconstructions at previous frame. The reference set, which consists of lowresolution and high-resolution patches, can be generated in both encoder and decoder by on-line learning. During the encoding of enhancement layer, a prediction is first gotten from base layer, from which low-resolution patches are extracted. These patches are then used as indices to find the matched high-resolution patches from the reference set. Finally, the prediction enhanced by the high-resolution patches is used for coding. The proposed approach does not need any motion bits. With our proposed FC approach, the performance of H.264 SVC can be improved up to 2.4dB in spatial scalable coding. Index Terms — video coding, motion estimation, scalable coding, spatial scalability 1.
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, 2016
"... Seascape genetics along a steep cline: using genetic patterns to test predictions of marine larval dispersal. Mol Ecol ..."
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Seascape genetics along a steep cline: using genetic patterns to test predictions of marine larval dispersal. Mol Ecol
