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Research on 3D stereoscopic images and videos has been extended quite a lot over the last 10 years. However, there is still empty space for objective quality metrics yet to come for 3D images and videos. Objective quality measurement is based on designing mathematical metrics which result in high correlation with subjective test results that take lots of time to perform in fact. This study mainly...
We have developed reduced reference parametric models for estimating perceived quality in audiovisual multimedia services. We have created 144 unique configurations for audiovisual content including various application and network parameters such as bitrates and distortions in terms of bandwidth, packet loss rate and jitter. To generate the data needed for model training and validation we have tasked...
Due to proliferation of mobile devices, the demand for video in cellular networks has increased exorbitantly. However, cellular networks have limited resources and the wireless medium is time-varying in nature. This necessitates the video streaming protocols to be re-designed taking into account the overall quality of experience (QoE) of the end users. In this paper, we propose a metric called enhanced-time...
The increasing variety of Linked Data on the Web makes it challenging to determine the quality of this data, and subsequently to make this information explicit to data consumers. Despite the availability of a number of tools and frameworks to assess Linked Data Quality, the output of such tools is not suitable for machine consumption, and thus consumers can hardly compare and rank datasets in the...
No-reference quality assessment is a challenging issue due to the non-existence of any information related to the reference and the unknown distortion type. The main goal is to design a computational method to objectively predict the human perceived quality of a distorted mesh and deal with the practical situation when the reference is not available. In this work, we design a no reference method that...
This paper proposes a prediction model for the perceptual quality of wireless 4kUHD H.265 video streaming. Based on Interval Type-2 Fuzzy Logic System (IT2FLS), the model exploits application and physical layer parameters. The results show that good prediction accuracy was obtained from the proposed prediction model. This study should help in the development of a reference-free video quality prediction...
During the process of image acquisition, images are often subject to out-of-focus or defocus blur because of the improper adjustment of the camera's focal length, this image blur will degrade the image quality. However, in the literature, image quality assessment (IQA) methods dedicated to evaluating the quality of images with out-of-focus blur remain few. Therefore, in this paper, we focus our attention...
A polynomial fitting model for predicting the RTP packet rate of Video-on-Demand received by a client is presented. This approach is underpinned by a parametric statistical model for the client-server system. This model, namely the PQ-model, improves the robustness of the predictor in the presence of a time-varying load on the server. The advantage of our approach is that if we model the load on the...
Adaptive video streaming has become prominent due to the rising diversity of Web-enabled personal devices. Common limitations in bandwidth and decoding power challenge the efficiency of content encoders to preserve visual quality at reduced data rates over a wide range of display resolutions. Objective assessment of perceptual video quality has greatly improved in the past decade but remains an open...
The quality of P2P streaming video is generally evaluated using objective or subjective metrics. But this task is even more complex in wireless multi-hop environments. In this paper we developed a statistical framework to evaluate the quality of Peer-to-Peer (P2P) video streaming on multi-hop wireless networks. First, we determine the factors that influence the performance of the P2P video streaming...
This paper presents a methodology for evaluation of video quality on OFDM-based networks. For such a purpose, measurements on a 5.8 GHz Wimax network were carried out in a controlled environment. The proposed methodology is based on mapping the PSNR (Peak Signal-to-Noise Ratio) loss on SNR (Signal-to-Noise ratio) values in a cross-layer analysis. This is achieved by reducing the base station transmitted...
HTTP Adaptive Streaming (HAS) adapts the video quality to the current network condition by switching between different quality layers. As HAS was shown to perform better than classical video streaming, it is becoming increasingly popular. Recent research showed that quality switch amplitude and time on layer have an impact on the Quality of Experience (QoE) of HAS. However, those studies focused only...
Image blur is a common type of image distortion in our daily life. Though traditional image quality assessment (IQA) is increasingly drawing the attention of the research community, the uncertainness and uniqueness which exists in blur images bring unexpected difficulties. We present a simple yet effective automatic method on assessing global invariant blurred images. Different from the traditional...
In this paper, we present an innovative algorithm based on a voting process approach, to analyse the data provided by an eye tracker during tasks of user evaluation of video quality. The algorithm relies on the hypothesis that a lower quality video is more “challenging” for the Human Visual System (HVS) than a high quality one, and therefore visual impairments influence the user viewing strategy....
With the popularity of the HTTP video streaming in mobile networks, the network operators are increasingly interested in the performance of the video streaming at the client-side. However, unlike content providers, network operators are not privy to the client-side or server-side, thus they have no good access to estimating the performance from the video state at the client-side. To address this limitation,...
Assessment and monitoring of speech quality in assistive hearing devices is of great interest to Audiologists, hearing researchers, device manufacturers and consumers. While subjective assessment of device quality is the “gold standard”, objective speech quality evaluation methods that emulate subjective perception are attractive for their efficiency and ease of use. This paper focuses on data-driven,...
Dimensionality Reduction (DR) is a crucial tool to facilitate high-dimensional data analysis. As the volume and the variety of features used to describe a phenomenon keeps increasing, DR has become not only desirable but paramount. However, DR can result in unreliable depictions of data. The uncertainties involved in DR may stem from the selection of methods, parameter configurations, and the constraints...
Speech quality evaluation is a very complex task with important applications. With the deployment of 3G and 4G networks, the end-user is requiring more quality of service. Currently, the assessment of speech quality over mobile phones is done in a controlled environment with a reference clean signal and its distorted version. However, this does not evaluate the quality of speech in a real-time situation...
In this paper, we first propose a novel no-reference (NR) image quality assessment (IQA) method for retargeted image based on the rank learning approach. Firstly, image features for each retargeted image are extracted, which should not only represent the image characteristics but also be sensitive to the retargeted distortions. Specifically, the image feature should be able to capture the shape distortions,...
A novel no-reference video quality assessment is proposed in this paper. The proposed metric is based on the combination of two-pass edge analysis and background subtraction. The two-pass edge analysis is a blur metric we proposed in our previous work, which has gain an efficient performance in image blur assessment and other image processing applications. We apply the two-pass edge analysis to the...
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