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Conference on Visual Communications and Image Processing 2005

作者： Xiong, RQ Xu, JZ Wu, F Li, SP Chinese Acad Sci Inst Comp Technol Beijing 100080 Peoples R China

ISBN: (纸本)0819459763

This paper makes a comparative study on the various spatial scalable coding frameworks. The frameworks with multiple image-domain motion aligned temporal filtering at various spatial resolutions, named as multi-T+2d, are mainly investigated. First we investigate a multi-T+2d scheme based on redundant frame representation. The cross spatial layer redundancy and prediction methods are discussed. The redundancy brings significant performance loss for schemes providing wide range SNR spatial scalability. To remove the redundancy produced in the multi-resolution temporal filtering while retaining the advantage of spatial-domain motion compensation, a novel non-redundant multi-T+2d scheme is proposed. Performance comparison is given among the discussed frameworks and it shows that the proposed non-redundant multi-T+2d framework has a good performance for fully scalable video coding. We also verify that the redundant multi-T+2d framework with cross spatial layer reconstruction feedback is practical in providing narrow range SNR scalability for each spatial layer.

关键词： spatial scalability 3d wavelet video coding motion aligned temporal filtering multiple resolution MATF in-scale MATF cross-layer redundancy subband coupling

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Optimal subband rate allocation for spatial scalability in 3d wavelet video coding with motion aligned temporal filtering

Optimal subband rate allocation for spatial scalability in 3...

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Conference on Visual Communications and Image Processing 2005

作者： Xiong, RQ Xu, JZ Wu, F Li, SP Zhang, YQ Chinese Acad Sci Inst Comp Technol Beijing 100080 Peoples R China

ISBN: (纸本)0819459763

The shift-variant property of discrete wavelet transform leads to the intrinsic coupling across various spatial subbands during motion aligned temporal filtering. It brings a big challenge how to achieve a better trade-off between subband independency and motion alignment efficiency in the context of providing spatial scalability in 3d wavelet video coding. This paper first investigates the issue of subband coupling in-depth. From the investigations on analysis and synthesis filters, we verify the existence and causes of subband coupling phenomenon and illustrate the subband leakage due to motion shift. Furthermore, we propose a method to measure the strength of this kind of coupling. Based on these investigations, we focus on schemes which preserving most subband coupling relationship and recommend that spatial highpass subbands should not be dropped completely. The issue of rate allocation for spatial highpass subbands is considered in this paper. An error propagation model is proposed to describe the effect of subband coupling in video reconstruction. The synthesis gain of each subband is estimated according to this model and it is finally adopted to guide the rate allocation algorithm. Experimental results have fully demonstrated the promising of the proposed techniques in improving both objective and subjective qualities of low resolution video, especially at middle and high bit rates, for 3d video coding schemes with spatial scalability.

关键词： 3d wavelet video coding spatial scalability subband coupling motion aligned temporal filtering error propagation subband rate allocation

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Motion compensated predictive subband coding of temporal lowpass frames from a 3d wavelet video coding scheme

Motion compensated predictive subband coding of temporal low...

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Conference on Visual Communications and Image Processing 2003

作者： Mayer, C Univ Aachen Rhein Westfal TH Aachen Inst Commun Engn D-52056 Aachen Germany

ISBN: (纸本)0819450235

In 3d wavelet video coding schemes, in which a temporal wavelet decomposition of the video data is combined with a spatial wavelet transform, temporal scalability and the reduction of temporal redundancy is often achieved at the expense of a delay. The delay increases according to the number of video frames that are jointly coded or, in other terms, according to the temporal wavelet transform depth. depending on the system delay that is allowed by a specific application, the maximum temporal transform depth might be limited. On the other hand. consecutive temporal lowpass frames at the highest permitted temporal decomposition level might still be strongly correlated, especially in case of video material with static background or low motion that can be optimally compensated. In this case, the temporal correlation should be exploited to improve the coding efficiency without inducing an additional delay to the overall system. In this paper, we consider a 3d wavelet video coding scheme in which the temporal wavelet decomposition precedes the spatial wavelet decomposition, and investigate the application of a spatially scalable wavelet video coder with in-band prediction to the temporal lowpass frames at the maximum temporal transform depth.

关键词： 3d wavelet video coding spatial scalability temporal scalability in-band prediction overcomplete discrete wavelet transform

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Performance of Spatial and Temporal Error Concealment Method for 3d dWT video coding in Packet Loss Channel

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IEICE TRANSACTIONS ON FUNdAMENTALS OF ELECTRONICS COMMUNICATIONS ANd COMPUTER SCIENCES 2012年第11期E95A卷 2015-2022页

作者： Tanaka, Hirokazu Kim, Sunmi Ogawa, Takahiro Haseyama, Miki Toshiba Co Ltd Minato Ku Tokyo 1058001 Japan Hokkaido Univ Grad Sch Informat Sci & Technol Sapporo Hokkaido 0600814 Japan

A new spatial and temporal error concealment method for three-dimensional discrete wavelet transform (3d dWT) video coding is analyzed. 3d dWT video coding employing dispersive grouping (dG) and two-step error concealment is an efficient method in a packet loss channel [20], [21]. In the two-step error concealment method, the interpolations are only spatially applied however, higher efficiency of the interpolation can be expected by utilizing spatial and temporal similarities. In this paper, we propose an enhanced spatial and temporal error concealment method in order to achieve higher error concealment (EC) performance in packet loss networks. In the temporal error concealment method, structural similarity (SSIM) index is employed for inter group of pictures (GOP) EC and minimum mean square error (MMSE) is used for intra GOP EC. Experimental results show that the proposed method can obtain remarkable performance compared with the conventional methods.

关键词： 3d wavelet video coding error-resilient video coding structural similarity index error concealment

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Overcomplete MCTF for improved spatial scalability in 3d wavelet video compression

Overcomplete MCTF for improved spatial scalability in 3D wav...

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Conference on Visual Communications and Image Processing 2005

作者： Rusert, T Ohm, JR Univ Aachen Rhein Westfal TH Aachen Int Commun Engn D-52056 Aachen Germany

ISBN: (纸本)0819459763

As of its open-loop structure and good decorrelation capability, motion-compensated temporal filtering (MCTF) provides a robust basis for highly-efficient scalable video coding. Combining MCTF with spatial wavelet decomposition and embedded quantization results in a 3d wavelet video compression system, providing temporal, spatial, and SNR scalability. Recent results indicate that the overall coding performance of these systems can be maximized if temporal filtering is performed in spatial domain (t+2d approach). However, as compared to non-scalable video coding, the performance of t+2d systems may not be satisfactory if spatial scalability needs to be provided. One important reason for this fact is the problem of spatial scalability of motion information. In this paper we present a conceptually new approach for t+2d-based video compression with spatially scalable motion information. We call our approach overcomplete MCTF since multiple spatial-domain temporal filtering operations are needed to generate the lower spatial scales of the temporal subbands. Specifically, the encoder performs MCTF-based generation of reference sequences for the coarser spatial scales. We find that the newly generated reference sequences are of satisfactory quality. Compared to the conventional t+2d system, our approach allows for optimization of the reconstruction quality at lower spatial scales while having reduced impact on the reconstruction quality at high spatial scales/bitrates.

关键词： MCTF 3d wavelet video coding spatial scalability motion scalability

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Motion-compensated 3d video coding using smooth transitions

Motion-compensated 3D video coding using smooth transitions

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Conference on Image and video Communications and Processing

作者： Hanke, K Rusert, T Ohm, JR Rhein Westfal TH Aachen Inst Commun Engn D-52056 Aachen Germany

ISBN: (纸本)0819448222

For exploitation of temporal interdependencies between consecutive frames, in existing 3d wavelet video coding concepts a blockwise motion estimation (ME) and compensation (MC) is employed. Because of local object motion, rotation or scaling, the processing of occlusion areas is problematic. In these regions, the calculation of correct motion vectors (MV) is not always possible and blocking artifacts may appear at the motion boundaries to the connected areas, for which uniquely referenced MV could be estimated. In order to avoid this, smooth transitions can be included around the occlusion pixels, which means to blur out the block artifacts. The proposed algorithm is based on the MC-EZBC 3d wavelet video coder (Motion-Compensated Embedded video coding algorithm using ZeroBlocks of subband / wavelet coefficients and Context modeling), which employs a lifting approach for temporal filtering [1].

关键词： 3d wavelet video coding motion-compensated temporal filtering artifact reduction deblocking

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Enhanced interframe wavelet video coding considering the interrelation of spatio-temporal transform and motion compensation

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SIGNAL PROCESSING-IMAGE COMMUNICATION 2004年第7期19卷 617-635页

作者： Rusert, T Hanke, K Mayer, C Rhein Westfal TH Aachen Inst Commun Engn D-52074 Aachen Germany

High coding performance and temporal, spatial, and SNR scalability are key elements required in future video applications. Within hybrid video coding schemes, scalability cannot be efficiently achieved due to the recursive coder structure. In motion-compensated interframe wavelet video coding, temporal filtering using wavelet filters and spatial wavelet decomposition are successively combined in an arbitrary manner, allowing for efficient spatio-temporal decor-relation and full scalability. depending on the particular succession of spatio-temporal decomposition, typical artifacts are induced, resulting in reduced subjective and objective coding performance. In this paper, these problems are addressed within the scope of a t + 2d scheme, where temporal filtering is followed by spatial transform coding, and possible solutions are discussed. Techniques for deblocking, adaptation of temporal and spatial filters, as well as for optimization of rate allocation are presented. (C) 2004 Elsevier B.V. All rights reserved.

关键词： 3d wavelet video coding lifting-based MCTF t+2d artifact reduction

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