Video quality

About: Video quality is a research topic. Over the lifetime, 13143 publications have been published within this topic receiving 178307 citations.

A perceptual quality assessment metric using temporal complexity and disparity information for stereoscopic video

Abstract: Visual discomfort/fatigue problems in 3D video have become an important issue. In this paper, we examine the factors that affect human perception of depth and visual comfort from stereoscopic video. For this, we conduct subjective quality assessments from which we extract four factors - temporal variance, disparity variation in intra-frames, disparity variation in inter-frames and disparity distribution of frame boundary areas. Based on these four factors, we design a no-reference stereoscopic video quality perception model (SV-QPM) as an objective quality assessment metric for stereoscopic video. The proposed SV-QPM does not require depth map but utilize the disparity information by simple estimation, and the model parameters are estimated based on linear regression. The experimental results show that our proposed model exhibits high consistency with subjective quality assessment results in terms of a Pearson correlation coefficient value of 0.808, and the prediction performance exhibits good consistency with zero outlier ratio value.

Noncollaborative Resource Management for Wireless Multimedia Applications Using Mechanism Design

Abstract: We propose to add a new dimension to existing wireless multimedia communications systems by enabling competing stations to proactively engage in the resource management game by adapting their cross-layer transmission strategies. For this, we model wireless stations (WSTAs) as rational and selfish players competing for available wireless resources in a dynamic game. We focus on polling-based wireless LAN (WLAN) networks, where developing an efficient solution for managing the available transmission opportunities is of paramount importance. The resource allocation game is coordinated by a network moderator, which deploys a novel resource management based on the Vickrey-Clarke-Groves (VCG) mechanism to determine a) the amount of time to be allocated to the various users and b) the transmission cost associated to the allocated resources. The transmission cost is referred to in the VCG mechanism as "transfer" and depends not on the used resources, but rather on the inconvenience (in terms of utility impact) that it causes to other WSTAs. The transfer is introduced in order to discourage WSTAs from lying about their resource requirements. Importantly, this proposed dynamic resource management approach for wireless multimedia applications changes the passive way stations are currently adapting their cross-layer strategies by enabling them to selfishly influence the wireless systems dynamics by proactively adapting their packet scheduling strategies, error protection strategies, etc. Hence, each wireless station can play the resource management game by adapting its multimedia transmission strategy depending on the experienced channel conditions, derived video quality, attitude towards risk, willingness to pay for resources and available information about the wireless network. Our simulations show that using the VCG mechanism the WSTAs do not have any incentives to lie about their resource requirements as otherwise they will be severely penalized by a high transfer. We also show that deploying advanced cross-layer strategies for playing the resource management game significantly benefit the WSTAs' received video quality. The willingness-to-pay for resources is introduced to provide WSTAs a tool to gather additional resources whenever they need to transmit an important (part of a) video sequence by agreeing to pay for resources an increased cost. A novel risk-aware scheduling scheme is also proposed that provides WSTAs the ability to dynamically avoid network congestion and hence, reduce their incurred transfer

Motion-based perceptual quality assessment of video

Abstract: There is a great deal of interest in methods to assess the perceptual quality of a video sequence in a full reference framework. Motion plays an important role in human perception of video and videos suffer from several artifacts that have to deal with inaccuracies in the representation of motion in the test video compared to the reference. However, existing algorithms to measure video quality focus primarily on capturing spatial artifacts in the video signal, and are inadequate at modeling motion perception and capturing temporal artifacts in videos. We present an objective, full reference video quality index known as the MOtion-based Video Integrity Evaluation (MOVIE) index that integrates both spatial and temporal aspects of distortion assessment. MOVIE explicitly uses motion information from the reference video and evaluates the quality of the test video along the motion trajectories of the reference video. The performance of MOVIE is evaluated using the VQEG FR-TV Phase I dataset and MOVIE is shown to be competitive with, and even out-perform, existing video quality assessment systems.

SDN Based QoE Optimization for HTTP-Based Adaptive Video Streaming

Abstract: Rapidly increasing volume of video streaming traffic creates a bandwidth crunch for service providers and network operators. Increased user expectations for higher quality video does not imply their willingness to pay higher monthly fees. Hence, more efficient bandwidth management schemes are needed to bridge the gap between growing demand from video traffic and existing network infrastructure. In this work, we present a novel bandwidth management solution for optimizing overall quality of experience (QoE) of multiple video streaming sessions. Instead of allocating bandwidth equally among competing flows, we propose to tailor the bandwidth allocation to both content complexity of requested video and playout buffer status of individual clients. We formulate the multi client bandwidth allocation problem within the convex optimization framework, which is flexible enough to accommodate a wide variety of video quality metrics. Further, we present a practical architecture based on software defined networking (SDN) with two components: video quality monitoring and video quality optimization. Testbed-based experiments confirm that with quality-optimized allocation the network can support up to 75% more users at the same level of quality-of-experience (QoE) than conventional equal-rate allocations.

Multichannel joint rate control of VBR MPEG encoded video for DBS applications

Abstract: A method to transmit multiplexed digital video that potentially allows for video quality and capacity gains over conventional constant bit-rate (CBR) transmission is described. The method uses a joint rate control algorithm that regulates the encoders during buffer congestion periods using bandwidth re-allocation and source rate control. A multichannel joint rate control algorithm is described and its performance simulated for MPEG encoded video on broadcast satellite (DBS) application. Results indicate significant capacity and/or quality gains over conventional CBR transmission methods. >