The contrast effect: QoE of mixed video-qualities at the same time
The contrast effect: QoE of mixed video-qualities at the same time
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对比效果：同时混合视频质量的 QoE
DOI：
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发表时间：
2018
期刊：
影响因子：
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通讯作者：
Pablo César
中科院分区：
文献类型：
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作者：
Marwin Schmitt;D. Bulterman;Pablo César
在桌面多方视频会议中，参与者的视频流以不同的质量传送，但我们对屏幕的这种组成如何影响体验质量知之甚少。不同的视频流是否充当间接质量参考，并且感知的视频质量因此取决于同一会话中的其他流？每个流的感知质量与整个会话的感知质量之间的关系如何？为了回答这些问题，我们进行了一项众包研究，其中我们收集了 5000 多个对整体会议和单个直播的感知质量评级。我们的结果显示了对比效果：当同时存在更多低质量流时，高质量流的评价更好，反之亦然。反过来，通过用高质量流交换低质量流，可以显着提高整个会话的质量感知。在比较个人和总体评分的平均值时，我们可以进一步观察到，当用户询问单个流时比总体评分更挑剔。然而，结果表明，虽然存在对比效应，但效果不够强，无法通过降低其他参与者的质量来优化体验。
In desktop multi-party video-conferencing videostreams of participants are delivered in different qualities, but we know little about how such composition of the screen affects the quality of experience. Do the different videostreams serve as indirect quality references and the perceived video quality is thus dependent on other streams in the same session? How is the relation between the perceived qualities of each stream and the perceived quality of the overall session? To answer these questions we conducted a crowdsourcing study, in which we gathered over 5000 perceived quality ratings of overall sessions and individual streams. Our results show a contrast effect: high quality streams are rated better when more low quality streams are co-present, and vice versa. In turn, the quality perception of an overall session can increase significantly by exchanging one low quality stream with a high quality one. When comparing the means of individual and overall ratings we can further observe that users are more critical when asked for individual streams than for an overall rating. However, the results show that while contrast effect exists, the effect is not strong enough, to optimize the experience by lowering the quality of other participants.