117 research outputs found
IMPROVING IMAGE QUALITY ASSESSMENT WITH MODELING VISUAL ATTENTION
Visual attention is an important attribute of the human visual system (HVS), while it has not been explored in image quality assessment adequately. This paper investigates the capabilities of visual attention models for image quality assessment in different scenarios: twodimensional images, stereoscopic images, and Digital Cinema setup. Three bottom-up attention models are employed to detect attention regions and find fixation points from an image and compute respective attention maps. Different approaches for integrating the visual attention models into several image quality metrics are evaluated with respect to three different image quality data sets. Experimental results demonstrate that visual attention is a positive factor that can not be ignored in improving the performance of image quality metrics in perceptual quality assessment. Index Terms — Visual attention, saliency, fixation, image quality metri
Perceptual Quality Assessment Based on Visual Attention Analysis
Most existing quality metrics do not take the human attention analysis into account. Attention to particular objects or regions is an important attribute of human vision and perception system in measuring perceived image and video qualities. This paper presents an approach for extracting visual attention regions based on a combination of a bottom-up saliency model and semantic image analysis. The use of PSNR (Peak Signal-to-Noise Ratio) and SSIM (Structural SIMilarity) in extracted attention regions is analyzed for image/video quality assessment, and a novel quality metric is proposed which can exploit the attributes of visual attention information adequately. The experimental results with respect to the subjective measurement demonstrate that the proposed metric outperforms the current methods
Comparing apples and oranges: assessment of the relative video quality in the presence of different types of distortions
<p>Abstract</p> <p>Video quality assessment is essential for the performance analysis of visual communication applications. Objective metrics can be used for estimating the relative quality differences, but they typically give reliable results only if the compared videos contain similar types of quality distortion. However, video compression typically produces different kinds of visual artifacts than transmission errors. In this article, we focus on a novel subjective quality assessment method that is suitable for comparing different types of quality distortions. The proposed method has been used to evaluate how well different objective quality metrics estimate the relative subjective quality levels for content with different types of quality distortions. Our conclusion is that none of the studied objective metrics works reliably for assessing the co-impact of compression artifacts and transmission errors on the subjective quality. Nevertheless, we have observed that the objective metrics' tendency to either over- or underestimate the perceived impact of transmission errors has a high correlation with the spatial and temporal activity levels of the content. Therefore, our results can be useful for improving the performance of objective metrics in the presence of both source and channel distortions.</p
FishIR : Identifying Pufferfish Individual based on Deep Learning and Face Recognition
Peer reviewe
Quality Assessment of In-the-Wild Videos
Quality assessment of in-the-wild videos is a challenging problem because of
the absence of reference videos and shooting distortions. Knowledge of the
human visual system can help establish methods for objective quality assessment
of in-the-wild videos. In this work, we show two eminent effects of the human
visual system, namely, content-dependency and temporal-memory effects, could be
used for this purpose. We propose an objective no-reference video quality
assessment method by integrating both effects into a deep neural network. For
content-dependency, we extract features from a pre-trained image classification
neural network for its inherent content-aware property. For temporal-memory
effects, long-term dependencies, especially the temporal hysteresis, are
integrated into the network with a gated recurrent unit and a
subjectively-inspired temporal pooling layer. To validate the performance of
our method, experiments are conducted on three publicly available in-the-wild
video quality assessment databases: KoNViD-1k, CVD2014, and LIVE-Qualcomm,
respectively. Experimental results demonstrate that our proposed method
outperforms five state-of-the-art methods by a large margin, specifically,
12.39%, 15.71%, 15.45%, and 18.09% overall performance improvements over the
second-best method VBLIINDS, in terms of SROCC, KROCC, PLCC and RMSE,
respectively. Moreover, the ablation study verifies the crucial role of both
the content-aware features and the modeling of temporal-memory effects. The
PyTorch implementation of our method is released at
https://github.com/lidq92/VSFA.Comment: 9 pages, 7 figures, 4 tables. ACM Multimedia 2019 camera ready. ->
Update alignment formatting of Table
Towards certification of 3D video quality assessment
Subjective quality assessment is widely used to understand and to study human perception of multimedia quality and as a basis for developing objective metrics to automatically predict the quality of audiovisual presentations. There are several recognized international protocols and procedures for reliable assessment of quality in multimedia systems and services, with emphasis on speech, audio and video modalities. However, the aspect of certification is not yet well understood in this context. This paper discusses various issues regarding certification of multimedia quality assessment. To be concrete, the discussion is illustrated by the procedure implemented to assess 3D video compression technologies within the MPEG effort for the definition of a 3D video coding standard. Selected results from four laboratories, Acreo, EPFL, NTNU and UBC, which participated in the assessment are presented. This case study is used in an early attempt to define a process for certification of subjective test campaigns, based on a cross-validation of the test results across different laboratories, towards the ultimate goal of Quality of Experience (QoE) certification
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