Topic
Video quality
About: Video quality is a research topic. Over the lifetime, 13143 publications have been published within this topic receiving 178307 citations.
Papers published on a yearly basis
Papers
More filters
24 Nov 2003
TL;DR: A double stimulus subjective evaluation was performed to determine preferred frame rates at a fixed bit rate for low bit rate video, with several notable content-based exceptions.
Abstract: A double stimulus subjective evaluation was performed to determine preferred frame rates at a fixed bit rate for low bit rate video. Stimuli consisted of eight reference color video sequences of size 352/spl times/240 pixels. These were compressed at rates of 100, 200 and 300 kbps for low, medium, and high motion sequences, respectively, using three encoders and frame rates of 10, 15 and 30 frames per second. Twenty-two viewers ranked their frame rate preferences using an adjectival categorical scale. Their preferences were analyzed across sequence content, motion type, and encoder. Viewers preferred a frame rate of 15 frames per second across all categories, with several notable content-based exceptions.
44 citations
TL;DR: This work presents a statistical model-based CU decision approach in which adaptive early termination thresholds are determined and updated based on the rate-distortion (RD) cost distribution, video content, and quantization parameters (QPs) and shows that the proposed method can reduce the complexity by about 56.76% and 55.61% on average.
Abstract: INTRA video coding is essential for high quality mobile video communication and industrial video applications since it enhances video quality, prevents error propagation, and facilitates random access. The latest high-efficiency video coding (HEVC) standard has adopted flexible quad-tree-based block structure and complex angular INTRA prediction to improve the coding efficiency. However, these technologies increase the coding complexity significantly, which consumes large hardware resources, computing time and power cost, and is an obstacle for real-time video applications. To reduce the coding complexity and save power cost, we propose a fast INTRA coding unit (CU) depth decision method based on statistical modeling and correlation analyses. First, we analyze the spatial CU depth correlation with different textures and present effective strategies to predict the most probable depth range based on the spatial correlation among CUs. Since the spatial correlation may fail for image boundary and transitional areas between textural and smooth areas, we then present a statistical model-based CU decision approach in which adaptive early termination thresholds are determined and updated based on the rate-distortion (RD) cost distribution, video content, and quantization parameters (QPs). Experimental results show that the proposed method can reduce the complexity by about 56.76% and 55.61% on average for various sequences and configurations; meanwhile, the RD degradation is negligible.
44 citations
23 Feb 2011
TL;DR: The impact and trade-offs of SVC-based quality adaptation with focus on the SVC layer selection algorithms are explored, which are performed at different streaming stages and give multimedia providers insights on how to design and fine-tune their VoD system in order to achieve best performance.
Abstract: P2P Video-on-Demand (VoD) based on Scalable Video Coding (SVC) (the scalable extension of the H.264/AVC standard) is gaining momentum in the research community, as it provides elegant adaptation to heterogeneous resources and network dynamics. The major question is, how do the adaptation algorithms and designs affect the overall perceived performance of the system? Better yet, how can the performance of an SVC-based VoD system be defined? This paper explores the impact and trade-offs of SVC-based quality adaptation with focus on the SVC layer selection algorithms, which are performed at different streaming stages. We carry out extensive experiments to evaluate the performance in terms of session quality (start-up delay, video stalls) and delivered SVC video quality (layer switches, received layers), and find out that these two metrics exhibit a trade-off. Our analysis and conclusions give multimedia providers insights on how to design and fine-tune their VoD system in order to achieve best performance.
44 citations
TL;DR: In this paper, a keyframe set is used to represent a video, motivated by the video summarization approach, and various image processing operations like blurring, gamma correction, JPEG compression and Gaussian noise addition are applied on the individual video frames to generate duplicate videos.
Abstract: A video "fingerprint" is a feature extracted from the video that should represent the video compactly, allowing faster search without compromising the retrieval accuracy. Here, we use a keyframe set to represent a video, motivated by the video summarization approach. We experiment with different features to represent each keyframe with the goal of identifying duplicate and similar videos. Various image processing operations like blurring, gamma correction, JPEG compression, and Gaussian noise addition are applied on the individual video frames to generate duplicate videos. Random and bursty frame drop errors of 20%, 40% and 60% (over the entire video) are also applied to create more noisy "duplicate" videos. The similar videos consist of videos with similar content but with varying camera angles, cuts, and idiosyncrasies that occur during successive retakes of a video. Among the feature sets used for comparison, for duplicate video detection, Compact Fourier-Mellin Transform (CFMT) performs the best while for similar video retrieval, Scale Invariant Feature Transform (SIFT) features are found to be better than comparable-dimension features. We also address the problem of retrieval of full-length videos with shorter-length clip queries. For identical feature size, CFMT performs the best for video retrieval.
44 citations
10 May 2011
TL;DR: This paper could identify the perceptual bottlenecks of the future wireless communication and are able to propose perceptual guidelines for mobility management and contributes to the service quality improvement of future wireless communications.
Abstract: Next Generation Mobile Networks (NGMNs) provide an all-IP wireless platform for multimedia service delivery. The integrated communication system creates new perspectives for wireless video distribution and quality provisioning. Depending on the mobility patterns of the nomadic users, the link layer characteristics may rapidly change. Furthermore, mobility and service adaptation events like network handovers, video bit rate switching, or codec changeovers, may affect the user perception. Provisioning “always best connected” video services requires a thorough knowledge of video quality perception in NGMNs. In this paper, we address this problem. A subjective test including 50 NGMN conditions has been carried out. They were arranged in groups to assess the impact on perceived quality of 1) the access technology and network handover, 2) video codecs and codec changeover, 3) video bit rate and bit rate switching, and 4) to provide guidelines for packet loss adaptation. We could identify the perceptual bottlenecks of the future wireless communication and are able to propose perceptual guidelines for mobility management. In this way, this paper contributes to the service quality improvement of future wireless communications.
44 citations