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Fast intra partition and mode prediction for equirectangular projection 360-degree video coding

IET image PROCESSING 2023年第2期17卷 558-569页

作者： Shu Zheng-Jie Peng Zong-Ju Jiang Gang-Yi Chen Fen Yuan Bo-Sen Ningbo Univ Fac Informat Sci & Engn Ningbo Peoples R China Chongqing Univ Technol Sch Elect & Elect Engn Chongqing 400054 Peoples R China

360-degree videos have drawn great attention from both the academia and the industry. For transmission and storage of 360-degree video, the joint video exploration team proposed the Versatile video coding (VVC) standard. VVC can significantly reduce the bitrate while maintaining the same subjective visual quality compared to the preceding high efficiency video coding. However, the computational complexity of VVC is extremely high which hinders the interactive applications. This paper proposes a fast intra partition method and mode prediction algorithm for equirectangular projection 360-degree video coding. First, a latitude-based preprocessing is introduced to early terminate the coding Unit (CU) partition in the polar region. Second, the support vector machine is used to predict the CU partition type. Third, the fast intra mode search method accelerates the intra mode prediction. Experimental results show that the proposed algorithm can significantly obtain an average time reduction rate of 60.40% and a Bjontegaard delta rate increase of 1.96%.

关键词： VVC preceding high efficiency video coding fast intra mode search method Support vector machines Optimisation techniques mode prediction algorithm search problems image and video coding joint video exploration team video coding support vector machines intra mode prediction equirectangular projection 360-degree video coding fast intra partition method Versatile video coding standard video signal processing coding Unit partition computational complexity

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Adaptive group-of-pictures and scene change detection methods based on existing H.264 advanced video coding information

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IET image PROCESSING 2008年第2期2卷 85-94页

作者： Ding, J. -R. Yang, J. -F Natl Cheng Kung Univ Dept Elect Engn Inst Comp & Commun Engn Tainan 70101 Taiwan

The H.264 advanced video coding (H.264/AVC) standard provides several advanced features such as improved coding efficiency and error robustness for video storage and transmission. In order to improve the coding performance of H.264/AVC, coding control parameters such as group-of-pictures (GOP) sizes should be adaptively adjusted according to different video content variations (VCVs), which can be extracted from temporal deviation between two consecutive frames. The authors present a simple VCV estimation to design adaptive GOP detection (AGD) and scene change detection (SCD) methods by using the obtained motion information, where the motion vectors and the sum of absolute transformed differences as VCV features are effectively used to design the AGD and SCD algorithms, respectively. In order to avoid unnecessary computation, the above VCV features are obtained only in the 4 x 4 inter-frame prediction mode. Simulation results show that the proposed AGD with SCD methods can increase the peak signal-to-noise ratio by 0.62 dB on average over the H.264/AVC operated with a fixed GOP size. Besides, the proposed SCID method can reach a scene change detection rate of 98%.

关键词： adaptive group-of-picture H.264 advanced video coding video coding Computer vision and image processing techniques image and video coding scene change detection method feature extraction motion estimation adaptive GOP detection motion vector video storage/transmission video content variation video signal processing

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Multiple weighted prediction models for video coding with brightness variations

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IET image PROCESSING 2012年第4期6卷 434-443页

作者： Tsang, S. -H. Chan, Y. -L. Siu, W. -C. Hong Kong Polytech Univ Dept Elect & Informat Engn Ctr Signal Proc Kowloon Hong Kong Peoples R China

Weighted prediction (WP) is a tool introduced in H. 264 to improve motion-compensation performance for video sequences with brightness variations. Various WP models to estimate the parameter set have been discussed in the literature. However, no single WP model works well for all types of brightness variations. A single reference frame multiple WP models (SRefMWP) scheme is proposed to facilitate the use of multiple WP models in a single reference frame. The proposed scheme makes a new arrangement of the multiple frame buffers in multiple reference frame motion estimation. It enables different macroblocks in the same frame to use different WP models even when they are predicted from the same reference frame. Furthermore, a new re-ordering mechanism for SRefMWP is also proposed to guarantee that the list of the reference picture is in the best order for further decreasing the bit rate. To reduce the implementation cost, a reduction in the memory requirement is achieved via look-up tables (LUTs). Experimental results show that SRefMWP can achieve significant coding gain in scenes with different types of brightness variations. Furthermore, SRefMWP with LUTs can reduce the memory requirement by about 80% while keeping the same coding efficiency as SRefMWP.

关键词： motion compensation H.264 multiple weighted prediction models video sequences table lookup brightness variations image and video coding Data handling techniques parameter set estimation single reference frame motion estimation look-up tables video coding image sequences LUT macroblocks multiple frame buffers memory requirement reduction reference picture video signal processing single reference frame multiple WP models re-ordering mechanism motion-compensation performance SRefMWP scheme multiple reference frame motion estimation

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Error concealment for motion-compensated interpolation

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IET image PROCESSING 2010年第3期4卷 195-210页

作者： Wu, Y. Swamy, M. N. S. Ahmad, M. O. Concordia Univ Dept Elect & Comp Engn Ctr Commun & Signal Proc Montreal PQ H3G 1M8 Canada

Motion-compensated interpolation is usually employed at the receiver end in order to improve the quality of the video, when a low-bit-rate video is encoded in conjunction with frame dropping. The authors propose a scheme that can exploit the block-based motion vector field available at the decoder to avoid the complex motion estimation. The scheme is based on an iterative refinement technique that employs the finite-element method to efficiently conceal the interpolation errors caused by unfilled holes or overlapped pixels in the predicted frames. As a consequence, no pixel classification is needed in the proposed scheme, thus reducing substantially the computational complexity. The scheme is capable of concealing the errors in the homogeneous regions as well as in regions containing sharp edges. The proposed scheme is simulated with the original frames of a number of test sequences, as well as implemented with the H.264/AVC decoded frames. The results from these extensive simulations show that the proposed scheme results in reconstructed frames having a better visual quality and a lower computational complexity than the existing schemes.

关键词： pixel classification finite element method motion compensation complex motion estimation Computer vision and image processing techniques image and video coding decoder frame dropping block-based motion vector field visual quality motion-compensated interpolation video coding error handling H.264/AVC decoded frames low bit rate video error concealment video signal processing iterative refinement technique computational complexity video quality interpolation errors

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video streaming transmission: performance modelling over wireless local area networks under saturation condition

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IET COMMUNICATIONS 2012年第1期6卷 13-21页

作者： Yao, X. W. Wang, W. L. Yang, S. H. Zhejiang Univ Technol Coll Comp Sci & Technol Hangzhou 310023 Zhejiang Peoples R China Univ Loughborough Dept Comp Sci Loughborough LE11 3TU Leics England

Transmitting delay-sensitive video streaming over IEEE 802.11e wireless local area networks (WLANs) is becoming increasingly popular. However, the transmission of real-time video streaming is very challenging because of the time-varying wireless channels and video content characteristics. The authors propose an accurate model to assess the perceived quality of video streaming over WLANs with enhanced distributed coordination function (EDCF) mechanism. The analytical model considers not only the packet loss caused by wireless interference and channel fading, but also the effects of loss from channel access competition. Based on the Markov chain, the authors then present the discrete probability distribution of medium access control (MAC) layer packet service time by using the signal transfer function of the generalised state transition diagram. Moreover, the coding relation of lost video frames is also explored in the performance analysis of the proposed model. Simulations based on Network Simulator 2 (NS-2) are conducted to verify the performance of the analytical model. The results show that the proposed model provides superior accuracy for the perceived quality of MPEG-4 video streaming over IEEE 802.11e EDCF-based WLANs.

关键词： wireless local area networks wireless interference image and video coding Protocols EDCF mechanism saturation condition medium access control IEEE 802.11e Markov chain video streaming transmission fading channels video streaming MPEG-4 channel fading NS-2 video coding performance modelling WLAN Computer communications enhanced distributed coordination function wireless LAN video signal processing Local area networks Network Simulator 2 access protocols real-time video streaming Radio links and equipment delay-sensitive video streaming MAC layer

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Digital watermarking: applications, techniques and challenges

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ELECTRONICS & COMMUNICATION ENGINEERING JOURNAL 1999年第4期11卷 173-183页

作者： Barnett, R Synteny Syst Maldon CM9 6SL Essex England

The explosive growth in the use of the Internet has made it an attractive medium for the distribution of multimedia material. However, it has become apparent that the digital nature of such material makes enforcement and proof of copyright ownership virtually impossible. Another problem with digital images and video is that undetectable modifications can be made with very simple and widely available equipment. As a result, the use of digital material for evidential purposes has been called into question at a time when the video surveillance industry is moving towards digital rather than analogue systems. Digital watermarking promises to address these issues. Different types of watermarking systems exist for different applications robust watermarks for copyright protection and fragile watermarks for integrity checking applications. The question is just how good are current digital watermark techniques and what are the issues surrounding their use in real-life situations?.

关键词： copyright ownership digital watermarking watermarking systems fragile watermarks Internet integrity checking applications security of data robust watermarks multimedia material distribution image coding Data security copyright protection surveillance Computer vision and image processing techniques image and video coding copyright digital images video signal processing video surveillance industry video coding digital video

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Biogeography-based optimisation search algorithm for block matching motion estimation

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IET image PROCESSING 2012年第7期6卷 1014-1023页

作者： Zhang, P. Wei, P. Yu, H. -Y. Univ Elect Sci & Technol China Sch Elect Engn Chengdu 611731 Peoples R China

Global optimisation methods such as genetic algorithm and particle swarm optimisation have been applied to motion estimation to prevent from being trapped into local minimum. However, their computational complexity is very high. To overcome this problem, a novel search algorithm for block motion estimation based on biogeography-based optimisation (BMEBBO) is proposed in this study. Since biogeography-based optimisation (BBO) has few initial parameters, fast convergence speed and high searching precision, BMEBBO can search global minimum effectively through the migration and the mutation operation of BBO. In addition, BMEBBO with chaotic search (BBOCHAO) is proposed to improve the local search ability of BMEBBO and a multi-mode algorithm combining BBOCHAO with diamond search (BBOCDS) is also proposed to improve the speed of BBOCHAO. Experimental results show that BBOCHAO has high prediction quality and low fluctuations of video quality especially for violent motion. BBOCDS can remarkably decrease the computational complexity of BBOCHAO with little sacrifice of peak signal-to-noise ratio. Moreover, BBOCDS is faster than test zero search algorithm in scalable video coding implementation with little sacrifice in rate-distortion sense.

关键词： BBOCHAO BBOCDS particle swarm optimisation search problems BMEBBO Optimisation techniques image and video coding genetic algorithm genetic algorithms motion estimation chaotic search peak signal-to-noise ratio image matching video coding diamond search algorithm block matching motion estimation mutation operation Biogeography-based optimisation search algorithm Computational complexity video signal processing computational complexity global optimisation method multimode algorithm rate distortion theory video quality rate-distortion sense

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QTMT-LNN: A fast intra CU partition using lightweight neural network for 360-degree video coding on VVC

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IET image PROCESSING 2023年第2期17卷 597-612页

作者： Sun, Zhewen Yu, Li Peng, Wei Huakhong Univ Sci & Technol Sch Elect Informat & Commun Wuhan 430074 Peoples R China

In the newest generation of video coding standard, Versatile video coding (VVC), a new technique called Quad Tree with nested Multi-type Tree (QTMT) structure is introduced. QTMT significantly improves the coding efficiency, but the improvement in compression performance comes at the cost of drastically increased complexity. This paper proposes a fast intra partition algorithm using Lightweight Neural Network (LNN) to skip QTMT partition steps which are unlikely to be chosen as the best split modes. Specifically, five LNNs (for five QTMT split modes) are trained, using features that consider the characteristic of 360-degree videos. The experimental results demonstrate that the proposed QTMT-LNN can reduce the encoding time from 52.28% to 72.17% on average, with coding efficiency losses ranging from 0.71% to 1.78%. Compared to other fast algorithms for intra coding unit (CU) partition, the method outperforms the related works in terms of Bjontegaard delta bit-rate (BDBR) and encoding time reduction.

关键词： efficiency losses 360-degree videos QTMT split modes 360-degree video coding coding efficiency QTMT-LNN newest generation image and video coding video coding fast intra CU partition Versatile video coding nested Multitype Tree structure QTMT partition steps video coding standard fast intra partition algorithm video signal processing quadtrees intra coding unit partition VVC Quad Tree lightweight neural network drastically increased complexity computational complexity Combinatorial mathematics

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Contribution of neural networks in image steganography, watermarking and encryption

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IET image PROCESSING 2023年第2期17卷 463-479页

作者： Rafidison, Maminiaina Alphonse Rafanantenana, Sabine Harisoa Jacques Rakotomihamina, Andry Harivony Toky, Rajaonarison Faniriharisoa Maxime Ramafiarisona, Hajasoa Malalatiana Univ Antananarivo Telecommun Automat Signal Image Res Lab Doctoral Sch Sci & Technol Engn & Innovat Antananarivo Madagascar

In front of information fishing, it is necessary to protect the information to be circulated over public channel. The goal of this paper is to propose an approach which inserts a logo inside of cover image and having three different possible results according to user's needs. The algorithm can perform steganography, watermarking or host encryption. This technique is based on singular value decomposition (SVD) and discrete wavelet transform (DWT) composed by three steps: pre-processing, embedding and extraction/decryption. Reference matrix and reference parameter are the two factors deciding the operation and the intervention of neural networks makes the choice of their parameters easier according to the desired result. For measuring the steganography performance, the authors adopt the structural similarity index measure (SSIM) which calculates the similarity between original and watermarked image and peak signal-to-noise ratio. For watermarking, the normalized correlation (NC) coefficient investigates the correlation between the original watermark and the extracted watermark. Attacking the watermarked image with common attacks used by previous publication searchers, the value of SSIM and NC coefficient are closed to one. Regarding peak signal-to-noise ratio, the overall score is around 61.73 dB. The performance score is not negligible also for the encryption method.

关键词： Integral transforms previous publication searchers Cryptography neural networks normalized correlation coefficient watermarking image steganography performance score image and video coding encryption method singular value decomposition image watermarking Computer vision and image processing techniques structural similarity index measure original watermark discrete wavelet transforms steganography performance reference parameter extracted watermark watermarked image Data security image coding information fishing host encryption steganography cover image public channel peak signal-to-noise ratio cryptography

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Efficient video coding using optimal compression plane and background modelling

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IET image PROCESSING 2012年第9期6卷 1311-1318页

作者： Paul, M. Charles Sturt Univ Sch Comp & Math Bathurst NSW 2795 Australia

All existing video coding standards consider a video as a temporal (along T-axis) collection of two-dimensional (2D) pictures (formed by XY-axes) and compress them by exploiting spatial and temporal redundancy in the pictures. A recent optimal compression plane (OCP) determination technique shows that better compression can be achieved by relaxing the physical meaning of axes by exploring information redundancy in a fuller extent where a video is considered as a 3D data cube. Spatial and temporal dimensions are determined based on the statistical redundancy along each axis. Treating a video as a 3D data cube revolutionises the traditional video features such as background, motion, object, zooming, panning etc. In this study, the authors apply dynamic background modelling to the OCP plane to exploit the newly generated background in the video for further improving the coding performance. The experimental results reveal that the proposed approach outperforms the existing state-of-the-art OCP technique as well as the H.264 video coding standard.

关键词： statistical redundancy spatial redundancy video coding optimal compression plane determination technique statistical analysis 2D picture 3D data cube temporal collection Other topics in statistics video coding standard dynamic background modelling image and video coding information redundancy spatial and temporal dimension temporal redundancy data compression video signal processing

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