Color compensation for multi-view video coding based on diversity of cameras

A novel color compensation method for multi-view video coding （MVC） is proposed, which efficiently exploits the inter-view dependencies between views with the existence of color mismatch caused by the diversity of cameras. A color compensation model is developed in RGB channels and then extended to YCbCr channels for practical use. A modified inter-view reference picture is constructed based on the color compensation model, which is more similar to the coding picture than the original inter-view reference picture. Moreover, the color compensation factors can be derived in both encoder and decoder, therefore no additional data need to be transmitted to the decoder. The experimental results show that the proposed method improves the coding efficiency of M VC and maintains good subjective quality.     

Local curve fitting based Lagrange multiplier selection for Id-slice in multi-view video coding

The rate and distortion of Id-slice do not fit the globally linear relationship on a logarithmic scale. Lagrange multiplier selection methods based on the globally linear approximate relationship are neither efficient nor optimal for multi-view video coding (MVC). To improve the coding efficiency of MVC, a local curve fitting based Lagrange multiplier selection method is proposed in this paper, where Lagrange multipliers are selected according to the local slopes of the approximate curves. Experimental results showed that the proposed method improves the coding efficiency. Up to 2.5 dB gain was achieved at low bitrates.     

Local curve fitting based Lagrange multiplier selection for Id-slice in multi-view video coding

The rate and distortion of Id-slice do not fit the globally linear relationship on a logarithmic scale. Lagrange multiplier selection methods based on the globally linear approximate relationship are neither efficient nor optimal for multi-view video coding （MVC）. To improve the coding efficiency of MVC, a local curve fitting based Lagrange multiplier selection method is proposed in this paper, where Lagrange multipliers are selected according to the local slopes of the approximate curves. Experimental results showed that the proposed method improves the coding efficiency. Up to 2.5 dB gain was achieved at low bitrates.     

PID-based bit allocation strategy for asymmetric stereoscopic video coding with fuzzy quality controller

Asymmetric stereoscopic video coding can take advantage of binocular suppression in human vision by representing one of the two views in lower quality.This paper proposes a bit allocation strategy for asymmetric stereoscopic video coding.In order to improve the accuracy of bit allocation and rate control in the left view,a proportionalintegral-derivative controller is adopted.Meanwhile,to control the quality fluctuation between consecutive frames of the left view,a quality controller is adopted.Besides,a fuzzy controller is proposed to control the variation in quality between the left and right views by comparing the PSNR disparity of two views with a fixed threshold,which is used to quantize the binocular psycho-visual redundancy and adjust the quantization parameter (QP) of the right view correspondingly.The proposed algorithm has been implemented in H.264/AVC video codec,and the experimental results show its effectiveness in rate control while keeping a good quality for the left view,and fewer bits are allocated for the right view so that the overall bit rate is saved by 7.2% at most without the loss of subjective visual quality for stereoscopic video.     

Very low bit-rate video coding based on wavelet transform

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一种基于结构相似度的多视点码率分配方法

多视点视频编码是当前视频编码领域的研究热点之一。在有限的网络带宽下,合理的码率分配可以提高视频主观视觉质量。本文提出一种基于结构相似度的码率分配方法,首先对视频帧提取基于结构相似度的显著图,然后结合显著图对重要宏块和非重要宏块分配不同的QP值,以达到码率分配的目的。实验结果表明,本文方法在有限的带宽下能有效的提高多视点视频的视觉主观质量。     

多视点视频编码预测结构的研究

不同的多视点视频序列具有不同的时空相关性,MVC采用的分层B帧预测结构无法充分利用视频序列的属性。本文提出了一种能适应不同视频序列编码的方法,通过研究多视点视频图像中的时空相关性和视点间的相关性,适当地取消部分时间层的视点间预测并且对所有P视点的非关键帧均采用视点间预测和调整了I视点的位置。实验结果表明,本文方法在提高编码效率的同时使得预测结构具有更好的随机访问性能、更低的编码复杂度。     

RTP payload format for H.264/SVC scalable video coding

The scalable extension of H.264/AVC, known as scalable video coding or SVC, is currently the main focus of the Joint Video Team‘s work. In its present working draft, the higher level syntax of SVC follows the design principles of H.264/AVC.Self-contained network abstraction layer units (NAL units) form natural entities for packetization. The SVC specification is by no means finalized yet, but nevertheless the work towards an optimized RTP payload format has already started. RFC 3984, the RTP payload specification for H.264/AVC has been taken as a starting point, but it became quickly clear that the scalable features of SVC require adaptation in at least the areas of capability/operation point signaling and documentation of the extended NAL unit header. This paper first gives an overview of the history of scalable video coding, and then reviews the video coding layer (VCL)and NAL of the latest SVC draft specification. Finally, it discusses different aspects of the draft SVC RTP payload format, including the design criteria, use cases, signaling and payload structure.     

基于JND和AR模型的感知视频编码方法(英文)

为了达到减少比特数同时保持画面质量的目的,提出了一种基于最小可视失真(JND)和自回归(AR)模型的感知视频编码方法.首先,设计了基于JND的纹理分割算法,建立了空时JND模型,以MB为基本单元,通过计算其JND能量并与阈值做比较,用以分割出视频序列中的纹理区域.然后,开发了AR模型来合成纹理区,在使用最小二乘法计算出AR模型的参数后,用相邻的前后参考帧对应像素的线性插值来生成重构像素.最后,为了检验所提方法的效果,将其与H.264/AVC视频编码系统做比较,用不同的视频序列实验来验证所提方法的有效性.实验结果显示,对于具有不同纹理特点的实验序列,所提方法可以在保持感知质量的同时将比特率减少15%～58%.     

H．264预测编码关键技术的研究分析

H．264是目前最新的视频编码标准，相对于以前的ITU—T视频编码标准和mpeg序列标准具有更高的压缩效率．编码效率的提高主要归根于精确的帧间预测编码，其中包括多种块模式．多参考帧运动估计和分数像素精度3种新技术的采用，对这些帧间预测编码技术进行研究和分析．主要是分析这些技术与H．264基本配置之间的比较。     

一种基于新阈值的视频编码全零块提早判决方法

为了降低计算复杂度和编码时间,提出了一种改进的H.264/AVC全零块提早判决方法.首先,介绍了已有的全零块判决算法,分析了3种变换后将量化为零的频域系数,并在3种不同频域伸缩因子的基础上推导出对应的空域系数.然后,根据这些空域系数,并应用Schwarz不等式原理,设定了3个全零块判决阈值,并根据全零块空域系数的分布情...     

Streaming and congestion control using scalable video coding based on H.264/AVC

INTRODUCTION Streaming of multimedia data over the Internet has rapidly increased in recent years. All commercial applications and most research in video streaming use conventional hybrid video coding. To adapt the data transmission rate on the server to the varying bandwidth caused by congestion in the Internet or to different available bandwidths of different clients, the simulcast solution is widely applied (Balk et al., 2003; Feamster et al., 2001; Schierl and Wiegand, 2004). A larg…     

Deadline-aware network coding for video on demand service over P2P networks

INTRODUCTION With the widespread deployment of broadband access, Video-on-Demand (VoD) streaming on the Internet has received increasing attention recently. In VoD service, video streams are delivered to asyn- chronous users with low delay and VCR-like opera- tion support (e.g., pause, fast-forward, and rewind). However, streaming to a large population of clients is very challenging due to the limited server capacity and little deployment of IP multicast in today’s Internet (Quinn a…     

Multiple description coding with spatial-temporal hybrid interpolation for video streaming in peer-to-peer networks

INTRODUCTION Multimedia services over the Internet are be- coming popular due to the widespread deployment of broadband access. However, the conventional cli- ent-server architecture severely limits the number of simultaneous users, especially for bandwidth inten- sive applications such as video streaming. P2P net- works, on the other hand, offer a solution to the scalability problem. As a node joins a P2P network, it not only consumes resources but also contributes its bandwidth or comp…     

A parallel memory architecture for video coding

To efficiently exploit the performance of single instruction multiple data （SIMD） architectures for video coding, a parallel memory architecture with power-of-two memory modules is proposed. It employs two novel skewing schemes to provide conflict-free access to adjacent elements （8-bit and 16-bit data types） or with power-of-two intervals in both horizontal and vertical directions, which were not possible in previous parallel memory architectures. Area consumptions and delay estimations are given respectively with 4, 8 and 16 memory modules. Under a 0.18-pm CMOS technology, the synthesis results show that the proposed system can achieve 230 MHz clock frequency with 16 memory modules at the cost of 19k gates when read and write latencies are 3 and 2 clock cycles, respectively. We implement the proposed parallel memory architecture on a video signal processor （VSP）. The results show that VSP enhanced with the proposed architecture achieves 1.28× speedups for H.264 real-time decoding.     

Multiple description scalable video coding based on 3D lifted wavelet transform

INTRODUCTION With the expansion of multimedia applications, video transmission is becoming an important issue in the research area of communication. It is very im- portant to compress a large amount of video data effectively, which has already attracted considerable attention recently. To make source coders both er- ror-resilient and network-adaptive are two main challenges facing the video compression techniques. It is necessary to make the bitstreams temporal, spa- tial and SNR scalabl…     

一种将增强层运动补偿与混合时空域的FGS融合的视频编码方案

1 Introduction Scalable coding has already been recognized as aneffective solution to resolve the network’s bandwidthvarying[1].It is also i mportant for video transmissionin error-prone environments , congest-prone networkand network with varying quality of service ,such aswireless video transmission systems .So it plays a veryi mportant role in both network communication andwireless communication. MPEG-4 video standard supports fine granularityscalability ( FGS) fine granularity scalabil…     

More efficient ground truth ROI image coding technique： implementation and wavelet based application analysis

In this paper, more efficient, low-complexity and reliable region of interest (ROI) image codec for compressing smooth low texture remote sensing images is proposed. We explore the efficiency of the modified ROI codec with respect to the selected set of convenient wavelet filters, which is a novel method. Such ROI coding experiment analysis representing low bit rate lossy to high quality lossless reconstruction with timing analysis is useful for improving remote sensing ground truth sur- veillance efficiency in terms of time and quality. The subjective [i.e. fair, five observer (HVS) evaluations using enhanced 3D picture view Hyper memory display technology] and the objective results revealed that for faster ground truth ROI coding applications, the Symlet-4 adaptation performs better than Biorthogonal 4.4 and Biorthogonal 6.8. However, the discrete Meyer wavelet adaptation is the best solution for delayed ROI image reconstructions.     

A novel algorithm for Ethernet-passive-optical-network dynamic bandwidth allocation based on threshold

The Ethernet passive optical network (EPON) is the next generation of broad-band network technique. A crucial issue in EPONs is the sharing of uplink bandwidth among optical network units (ONUs). This article provides a novel dynamic bandwidth allocation algorithm, i.e. threshold dynamic bandwidth allocation (TDBA), which is based on adaptive threshold, to increase resource utilization. The algorithm uses ONU data-transmitting rate to adjust optical line terminal (OLT) receiving data threshold from an ONU. Simulation results show that this algorithm can decrease average packet delay and increase network throughput in a 10G EPON system.     

接头角板位置对客车三杆结构承载特性的影响

应用有限元方法,计算分析不同数量及不同的接头角板位置对相互垂直的不等宽空间三杆结构的承载性能影响,结果表明,角板平面与载荷力平行时,能有效提高结构的刚度和强度;与载荷力垂直方向时,对结构刚度与强度影响很小;接头角板位置不同,对结构刚度占强度影响也是不同.