Video quality

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

Method and system for video quality assessment

Abstract: A method and system for automated video quality assessment which reduces the adverse effects of sub-field/frame misalignments between the reference and test sequences. More particularly, the invention provides for misalignments down to a sub-field/frame level to be handled by individually matching sub-field/frame elements of a test video field/frame with sub-field/frame elements from a reference video field/frame. The use of a matching element size that is significantly smaller than the video field/frame size enables transient sub-field/frame misalignments to be effectively tracked.

Development of opinion-based audiovisual quality models for desktop video-teleconferencing

Abstract: This paper discusses the analysis of an audiovisual desktop video-teleconferencing subjective experiment conducted at the Institute for Telecommunication Sciences. Objective models of the individual audio and video quality are presented. Also discussed is an objective model of the audiovisual quality based upon the results of the individual objective audio and video quality models. Finally, a subjective model of audiovisual quality based upon users' ratings of the audio and video quality is discussed.

The correlation structure for a class of scene-based video models and its impact on the dimensioning of video buffers

Abstract: We analyze the autocorrelation structure for a class of scene-based MPEG video models at the groups-of-pictures (GOP) (course grain) and frame (fine grain) levels assuming an arbitrary scene-length distribution. At the GOP level, we establish the relationship between the scene-length statistics and the short-range/long-range dependence (SRD/LRD) of the underlying model. We formally show that when the intrascene dynamics exhibit SRD, the overall model exhibits LRD if and only if the second moment of the scene length is infinite. Our results provide the theoretical foundation for several empirically derived scene-based models. We then study the impact of traffic correlations on the packet loss performance at a video buffer. Two popular families of scene-length distributions are investigated: Pareto and Weibull. In the case of Pareto distributed scene lengths, it is observed that the performance is rather insensitive to changes in the buffer size even as the video model enters the SRD regime. For Weibull distributed scene lengths, we observe that for small buffers the loss performance under a frame-level model can be larger than its GOP-level counterpart by orders of magnitude. In this case, the reliance on GOP-level models will result in very optimistic results.

Awareness driven video quality of service in collaborative virtual environments

Abstract: We extend previous work on texture mapping video streams into virtual environments by introducing awareness driven video QoS. This uses movements within a shared virtual world to activate different video services. In turn, these services have different settings for underlying QoS parameters such as frame-rate, resolution and compression. We demonstrate this technique through a combined conferencing! mediaspace application which uses awareness driven video for facial expressions and for views into remote physical environments. We reflect on the issues of spatial consistency, privacy, seamless shifts in mutual involvement and making underlying QoS mechanisms more visible, malleable and flexible.

Human visual system based objective digital video quality metrics

Abstract: We present a review on human visual system (HVS) based digital video quality metrics. Particularly, three objective video quality metrics are discussed and analyzed in detail because they represent the state-of-the-art of HVS based quality metric research and have been proposed to and verified by VQEG (Video Quality Expert Group) as the candidates of a possible ITU standard. The purpose of the paper is to provide an up-to-date knowledge of the HVS modeling, how the characteristics of the HVS have been incorporated into quality metrics, and the implementation issues of the metrics as well as the directions of future research.