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One of the challenges in video rate control lies in accurately achieving the target bitrate by determining coding parameter set. In HEVC, nontexture bits become more significantly important, due to the adoption of more coding tools compared to H.264 standards. In this paper, we propose an accurate rate model to estimate the size of nontexture bits accurately. In addition, parameter update conditions...
Although High Dynamic Range (HDR) content can provide an enhanced immersive experience for end-users, the impact of channel errors on its perception is unclear due to the lack of a standardized HDR video distribution framework. This paper presents an assessment of the robustness of the two main HDR video distribution architectures, the single-layer 10-bit scheme and the two-layer 8-bit backward-compatible...
Phase Congruency (PC) features are firstly introduced into image and video coding field in this paper. As an effective tool to measure the edge information for image textures, PC change can be used to evaluate the compression loss, i.e. the coding distortions in image and video coding. Firstly, the compression influences on PC maps are given and analyzed. Secondly, the relationship between the consumed...
Addressing transmission errors in underwater acoustic channels is a key challenge for the real-time video communication between an autonomous underwater vehicle and a surface station. In this paper, we propose an error-resilient video compression technique based on hybrid multiple descriptions and redundant pictures to overcome impact of packet loss in underwater acoustic transmission. Video sequences...
While statistical redundancy removal has been extensively studied as a core technology of traditional video encoders, visual attention can be further exploited to improve coding efficiency. In this paper, we present an optimization strategy of video coding based on visual-attention area extraction. The proposed algorithm is a three-step method. First, a visual-attention map is generated with a spatio-temporal...
Encoders based on the High Efficiency Video Coding (HEVC) standard consider an input sequence as a succession of slices grouped in Structures of Pictures (SOP). The SOP used while encoding specifies many parameters, such as the coding order of frames, or the reference frames used during inter-prediction. Reference encoders typically make use of a fixed SOP structure of a given size, which is periodically...
Low-bitrate video compression is a challenging task, particularly with the increasing complexity of video sequences. Re-shaping video data before its compression with modern hybrid encoders has provided interesting results in the low and ultra-low bit rate domains. In this work, we propose a novel saliency guided preprocessing approach, which combines adaptive re-sampling and background texture removal,...
Live video streaming from mobile devices is quickly becoming popular through services such as Periscope, Meerkat, and Facebook Live. Little is known, however, about how such services tackle the challenges of the live mobile streaming scenario. This work addresses such gap by investigating in details the characteristics of the Periscope service. A large number of publicly available streams have been...
Fisheye cameras have become extremely popular in applications where the goal is to capture large fields of view with only one camera. However, the wide-angle fisheye imagery has special characteristics that may not be very well suited for modern video codecs that employ block-based translational motion model. This model fails to describe complex deformable motion which is often present in fisheye...
Regular omnidirectional video encoding technics use map projection to flatten a scene from a spherical shape into one or several 2D shapes. Common projection methods including equirectangular and cubic projection have varying levels of interpolation that create a large number of non-information-carrying pixels that lead to wasted bitrate. In this paper, we propose a tile based omnidirectional video...
A cloud-based encoding pipeline which generates streams for video-on-demand distribution typically processes a wide diversity of content that exhibit varying signal characteristics. To produce the best quality video streams, the system needs to adapt the encoding to each piece of content, in an automated and scalable way. In this paper, we describe two algorithm optimizations for a distributed cloud-based...
The upcoming JPEG XT standard for High Dynamic Range (HDR) images defines a common framework for the lossy and lossless representation of high-dynamic range images. It describes the decoding process as the combination of various processing tools that can be combined freely. In this paper we analyze the coding efficiency of different decoding tools through a large scale objective quality testing using...
This paper studies the influence of JPEG-XT on LDR generation using TMOs'. JPEG-XT encodes HDR images into a two layer scheme, encoding a LDR version of the image in a base layer, and the residual HDR information in an enhancement layer. The question addressed here is to understand if this model allows to extract a new LDR representation using a different TMO, independently of the TMO used to generate...
The latest video compression standard HEVC sets new benchmarks concerning the efficiency for both video coding and also still image coding, i.e., pure intra picture coding. Nevertheless, its high complexity created by the rate-distortion optimization procedure is a serious drawback. To reduce this computational burden, several algorithms for fast mode decision have been proposed. However, most of...
In the absence of a commercial High Dynamic Range (HDR) distribution pipeline, two-layer backward-compatible HDR video coding is a viable solution for the imminent transition from Low Dynamic Range (LDR) to HDR content transmission. However, the performance of a two-layer coding solution is governed by the extension layer coding performance. In this paper, we propose an improved two-layer backward-compatible...
Real-time video applications, such as multi party video conferencing, involve the simultaneous transport of multiple and potentially multi-layered video sources to participating or interested parties. It is desirable to mix these multiple source videos into a single video stream at intermediary nodes in the network, e.g. at Multipoint Control Units (MCU). This has the advantage of reduced application...
While a number of existing high-bit depth video compression methods can potentially encode high dynamic range (HDR) video, few of them provide this capability. In this paper, we investigate techniques for adapting HDR video for this purpose. In a large-scale test on 33 HDR video sequences, we compare 2 video codecs, 4 luminance encoding techniques (transfer functions) and 3 color encoding methods,...
Inspired by recent advances in objective video quality assessment, this paper proposes a novel, local quantisation parameter (QP) determination approach for perceptual video compression, based on the experimental results of a QP selection test. This method has been fully integrated into the High Efficiency Video Coding (HEVC) reference codec for intra coding, which predicts coding tree unit (CTU)...
This paper investigates the effect that the QP offset value has on the coding performance of HEVC. We relate QP offset to the type of texture content present in the sequence. These then are used to develop a low-complexity adaptive QP offset selection method. This enables in-loop configuration of the QP offset parameter in a way that is content dependent and utilizes available encoding statistics...
Optimal rate allocation is among the most challenging tasks to perform in the context of multi-view video coding, because of the dependency between frames induced by motion compensation and depth image-based rendering. In this paper, using a recursive rate-distortion model that explicitly takes into account these dependencies, we approach the frame-level rate allocation as a convex optimization problem...
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