Video quality

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

Vision and Video: Models and Applications

Abstract: While traditional analog systems still form the vast majority of television sets today, production studios, broadcasters and network providers have been installing digital video equipment at an ever-increasing rate. The border line between analog and digital video is moving closer and closer to the consumer. Digital satellite and cable service have been available for a while, and recently terrestrial digital television broadcast has been introduced in a number of locations around the world.

GamingVideoSET: a dataset for gaming video streaming applications

Abstract: This paper presents GamingVideoSET1, a dataset consisting of twenty-four uncompressed raw gaming videos of 30 seconds duration, 1080p resolution, and 30 fps for the research community working on gaming video quality assessment. Furthermore, the data set includes subjective quality assessment results for 90 video sequences obtained by encoding six different gaming videos using the H.264/MPEG-AVC codec standard in 15 different resolution-bitrate pairs (three resolution, five bitrates each). In addition to the reference videos, the dataset offers a total of 576 distorted videos in MP4 format, obtained by encoding the videos in 24 different resolution-bitrate pairs, and their objective quality assessment results (average and per-frame) using three video quality assessment metrics. 1The database is available at https://kingston.box.com/v/GamingVideoSET

Allocation of layer bandwidths and FECs for video multicast over wired and wireless networks

Abstract: Layered multicast is an efficient technique to deliver video to heterogeneous receivers over wired and wireless networks. We consider such a multicast system in which the server adapts the bandwidth and forward-error correction code (FEC) of each layer so as to maximize the overall video quality, given the heterogeneous client characteristics in terms of their end-to-end bandwidth, packet drop rate over the wired network, and bit-error rate in the wireless hop. In terms of FECs, we also study the value of a gateway which "transcodes" packet-level FECs to byte-level FECs before forwarding packets from the wired network to the wireless clients. We present an analysis of the system, propose an efficient algorithm on FEC allocation for the base layer, and formulate a dynamic program with a fast and accurate approximation for the joint bandwidth and FEC allocation of the enhancement layers. Our results show that a transcoding gateway performs only slightly better than the nontranscoding one in terms of end-to-end loss rate, and our allocation is effective in terms of FEC parity and bandwidth served to each user.

Efficient PFD-Based Networking and Buffering Models for Improving Video Quality over Congested Links

Abstract: Video traffic over the Internet becomes increasingly popular and is expected to comprise the largest proportion of the traffic carried by wired and wireless networks. On the other hand, videos are usually compressed by exploiting spatial and temporal redundancy for the reason of increasing the number of video streams that can be simultaneously carried over links. Unfortunately, receiving high-quality video streaming over the Internet remains a challenge due to the packet loss encountered in the congested wired and wireless links. In addition, the problem is more apparent in wireless links due to not only employing limited system capacity, but also some of the major drawbacks of wireless networks, out of which the bandwidth limitations and link asymmetry which refers to the situation where the forward and reverse paths of a transmission have different channel capacities. Therefore, the wireless hops may be congested which result in dropping many video frames. Additionally, as a result of compressing videos, dependencies among frames and within a frame arise. Consequently, the overall video quality tends to be degraded dramatically. The main challenge is to support the growth of video traffic while keeping the perceived quality of the delivered videos high. In this paper, we extend our previous work concerning improving video traffic over wireless networks through professionally studying the dependencies between video frames and their implications on the overall network performance. In other words, we propose very efficient network and buffer models proportionately to novel algorithms that aim to minimize the cost of aforementioned possible losses by selectively discarding frames based on their contribution to picture quality, namely, partial and selective partial frame discarding policies considering the dependencies between video frames. The performance metrics that are employed to evaluate the performance of the proposed algorithms include the rate of non-decodable frames, peak signal-to-noise ratio, frameput, average buffer occupancy, average packet delay, as well as jitter. Our results are so promising and show significant improvements in the perceived video quality over what is relevant in the current literature. We do not end up to this extent, but rather the effect of producing different bit-stream rates by the FFMPEG codecs on aforementioned performance metrics has been extensively studied.

Study of Saliency in Objective Video Quality Assessment

Abstract: Reliably predicting video quality as perceived by humans remains challenging and is of high practical relevance. A significant research trend is to investigate visual saliency and its implications for video quality assessment. Fundamental problems regarding how to acquire reliable eye-tracking data for the purpose of video quality research and how saliency should be incorporated in objective video quality metrics (VQMs) are largely unsolved. In this paper, we propose a refined methodology for reliably collecting eye-tracking data, which essentially eliminates bias induced by each subject having to view multiple variations of the same scene in a conventional experiment. We performed a large-scale eye-tracking experiment that involved 160 human observers and 160 video stimuli distorted with different distortion types at various degradation levels. The measured saliency was integrated into several best known VQMs in the literature. With the assurance of the reliability of the saliency data, we thoroughly assessed the capabilities of saliency in improving the performance of VQMs, and devised a novel approach for optimal use of saliency in VQMs. We also evaluated to what extent the state-of-the-art computational saliency models can improve VQMs in comparison to the improvement achieved by using “ground truth” eye-tracking data. The eye-tracking database is made publicly available to the research community.