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In this paper, we address the problem of the statistical multiplexing of video streams. Dynamic bitrate allocation is used to improve the overall video quality of a pool of channels. The balance is obtained by providing more bits to complex channels, while deprivations are applied to non-complex ones. In this study, the error minimization optimization of several compressed video is considered along...
Segment-based temporal prediction combined with higher-order motion models have been studied as an alternative to conventional block-based translational inter prediction. One example of such studies is known as motion hints, where an affine motion model has been used. In this paper, we explore the applicability of motion hints with an elastic motion model in generating reference frames for conventionally...
High Efficiency Video Coding (HEVC) is the latest video coding standard and has achieved 50% better compression performance compared to prior video standards competing with (2K, 4K, and 8K) video resolutions. HEVC adopts flexible quad-tree structure, resulting 60% of inter prediction complexity. A fast coding unit decision taking algorithm is proposed which can reduce the coding tree unit (CTU) inter...
The motion estimation and motion compensation techniques are widely used in video compression by different video codecs like MPEG2, MPEG4. Fast and precise algorithms are needed to target the need of real time video processing of high quality videos in emerging applications. Many fast block motion search algorithms have been developed to minimize computational cost required by full search algorithm,...
This paper presents the results of a subjective evaluation experiment, made to compare different HDR coding technologies, conducted at the recent ITU/ISO/IEC VCEG/ MPEG/JPEG Meeting in San Diego, CA, February 2016. A set of “anchor” streams, conforming to the HDR10 spec, was compared to a similar rate-matched set obtained using a method called “Reshaper”, which requires normative changes to the underlying...
Error resilience (ER) and error concealment (EC) are important tools in video transmission over lossy channels. Notably, when maximizing Quality of Experience (QoE) instead of Quality of Service (QoS), some designs of multiple description coding (MDC) schemes are promising. MDC is categorized into different types and, in this paper, we focus on temporal MDC techniques. In video coding, such as MDC,...
In this paper, we present a depth map rate control algorithm for the High Efficiency Video Coding (HEVC) Multi-View Video plus Depth (MVD) representation. The proposed algorithm is based on a bit allocation refinement technique for key frames together with a depth-map inspired R-λ model coupled with an adaptive clipping algorithm designed to exploit the depth map characteristics. This results in improved...
Given its potential for more realistic rendering and enhanced user experience, High Dynamic Range (HDR) imaging is raising a lot of interest both in industry and academia. In this context, efficient representation and coding techniques are needed, as HDR video entails significantly higher raw data rate. In this paper, we present a temporally constrained content-adaptive Tone Mapping Operator (TMO)...
Plenoptic images are one type of light field contents produced by using a combination of a conventional camera and an additional optical component in the form of microlens arrays, which are positioned in front of the image sensor surface. This camera setup can capture a sub-sampling of the light field with high spatial fidelity over a small range, and with a more coarsely sampled angle range. The...
In the second generation of Audio Video coding Standard(AVS2), the encoder tries all possible depth levels in order to select the best partition pattern for coding unit (CU) and prediction unit (PU). In this paper, we proposed an adaptive fast algorithm based on variance, which can effectually reduce the total encoding time with negligible bitrate increment for AVS2. Our algorithm utilizes the variance...
To date, most resource allocation proposals in elastic optical networks have focused either on routing and spectrum assignment (RSA, assuming fixed coding scheme and modulation format) or routing, modulation level and spectrum assignment (RMLSA, assuming a fixed coding scheme). Recent research has studied the impact of adaptive assignment of the code rate, without adapting the modulation format (RCSA...
In this paper, we present a QoS-adaptive framework for screen sharing over heterogeneous networks. Basic requirements and important issues of a screen sharing system are described. For determining optimal video coding parameters, adaptation trajectory is used as the hints in making decisions. Further, experiments are carried out to investigate the trade-off between video bitrate and the buffering...
For low bit rate scenarios (video conferencing, aerial surveillance), conventional video coding is unable to meet the small bit rate and high quality requirements. In contrast to that Region of Interest (ROI) coding provides an efficient compression by improving the quality of ROIs at the expense of non-ROIs. We also transmit ROI only, but reconstruct non-ROI from already transmitted content by means...
Low bit rate transmission of HD video captured from UAVs is highly interesting. Assuming a planar surface, areas contained in the current frame but not in the previous frames (New Area) can be reconstructed using Global Motion Compensation (GMC). Aiming at stereo reconstruction from monocular video by using motion parallax, a second view of each image pixel has to be additionally transmitted. Whereas...
This paper deals with objective video assessment methods. The paper begins with a short introduction to video quality evaluation methods. Mainly it is concentrated to common objective measurement methods including Peak to Signal Noise Ratio (PSNR), Structural Similarity (SSIM), and Mean-Singular Value Decomposition (M-SVD). Next part of this paper describes a new application developed for video sequence...
Different with traditional videos, three dimensional video (3DV) contains multiview videos as well as their corresponding depth maps. Depth maps are not used for viewing, but for rendering virtual views. Therefore, the quality of virtual view should be taken into account during depth compression. A modified distortion model is proposed to be used as the distortion criterion during the compression...
Recently, parametric models of predicting video subjective quality by exploiting packet layer or bit stream layer information at decoder side has achieved significant progress. In contrast, there are few works on estimating subjective quality in the stage of video encoding, partially because of limited and outdated dataset. In this paper, we contribute a new 4K video dataset with full subjective scores...
Audio quality evaluation for audio material of intermediate and high quality requires expert listeners. In comparison to non-experts, these are not only more critical in their ratings, but also employ different strategies in their evaluation. In particular they concentrate on shorter sections of the audio signal and compare more to the reference than inexperienced listeners.
Most video platforms deliver HD video in high bitrate encoding. Modern video-conferencing systems are capable of handling HD streams, but using multiparty conferencing, average internet connections in the home are on their bandwidth limit. For properly managing the encoding bitrate in videoconferencing, we must know what is the minimum bitrate requirement to provide users an acceptable experience,...
Adaptive crowdsourcing is a new approach to crowdsourced Quality of Experience (QoE) studies, which aims to improve the certainty of resulting QoE models by adaptively distributing a fixed budget of user ratings to the test conditions. The main idea of the adaptation is to dynamically allocate the next rating to a condition, for which the submitted ratings so far show a low certainty. This paper investigates...
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