Department of Telecommunications, VSB-Technical University of Ostrava, 708 00 Ostrava, Czech Republic.
Department of Multimedia and Information-Communication Technology, University of Zilina, Univerzitna 1, 010 26 Zilina, Slovakia.
Sensors (Basel). 2021 Mar 10;21(6):1949. doi: 10.3390/s21061949.
Video quality evaluation needs a combined approach that includes subjective and objective metrics, testing, and monitoring of the network. This paper deals with the novel approach of mapping quality of service (QoS) to quality of experience (QoE) using QoE metrics to determine user satisfaction limits, and applying QoS tools to provide the minimum QoE expected by users. Our aim was to connect objective estimations of video quality with the subjective estimations. A comprehensive tool for the estimation of the subjective evaluation is proposed. This new idea is based on the evaluation and marking of video sequences using the sentinel flag derived from spatial information (SI) and temporal information (TI) in individual video frames. The authors of this paper created a video database for quality evaluation, and derived SI and TI from each video sequence for classifying the scenes. Video scenes from the database were evaluated by objective and subjective assessment. Based on the results, a new model for prediction of subjective quality is defined and presented in this paper. This quality is predicted using an artificial neural network based on the objective evaluation and the type of video sequences defined by qualitative parameters such as resolution, compression standard, and bitstream. Furthermore, the authors created an optimum mapping function to define the threshold for the variable bitrate setting based on the flag in the video, determining the type of scene in the proposed model. This function allows one to allocate a bitrate dynamically for a particular segment of the scene and maintains the desired quality. Our proposed model can help video service providers with the increasing the comfort of the end users. The variable bitstream ensures consistent video quality and customer satisfaction, while network resources are used effectively. The proposed model can also predict the appropriate bitrate based on the required quality of video sequences, defined using either objective or subjective assessment.
视频质量评估需要一种综合方法,包括主观和客观指标、测试和网络监测。本文涉及一种新颖的方法,即使用体验质量 (QoE) 指标将服务质量 (QoS) 映射到体验质量 (QoE),以确定用户满意度的限制,并应用 QoS 工具来提供用户期望的最低 QoE。我们的目标是将视频质量的客观估计与主观估计联系起来。提出了一种用于主观评估估计的综合工具。这个新想法基于使用来自单个视频帧中的空间信息 (SI) 和时间信息 (TI) 的哨兵标志对视频序列进行评估和标记。本文的作者创建了一个用于质量评估的视频数据库,并从每个视频序列中得出 SI 和 TI,以便对场景进行分类。使用客观和主观评估对视频场景进行评估。基于结果,本文定义并提出了一种用于预测主观质量的新模型。该质量是使用基于客观评估和通过定性参数(如分辨率、压缩标准和码流)定义的视频序列类型的基于人工神经网络进行预测的。此外,作者创建了一个最优映射函数,用于根据视频中的标志定义可变比特率设置的阈值,确定所提出模型中的场景类型。该函数允许根据场景的特定片段动态分配比特率,并保持所需的质量。我们提出的模型可以帮助视频服务提供商提高最终用户的舒适度。可变比特流确保了视频质量和客户满意度的一致性,同时有效利用了网络资源。该模型还可以根据使用客观或主观评估定义的视频序列所需的质量来预测适当的比特率。