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

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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Very low bit rate video coding using arbitrarily shaped region-based motion compensation

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1995年第6期5卷 500-507页

作者： Yokoyama, Y Miyamoto, Y Ohta, M Informatlon Technology Research Laboratories NEC Corporation Limited Kawasaki Kanagawa Japan Nihon Denki Kabushiki Kaisha Minato-ku Tokyo JP Inf. Technol. Res. Labs. NEC Corp. Kawasaki Japan

This paper presents a novel region-based video coding algorithm for very low bit-rate transmission. A huge amount of region shape information in a conventional region-based coding does not need to be transmitted in the new approach, because it can be synchronously obtained from a reconstructed picture in both encoder and decoder by image segmentation. Segmented region updating, which can obtain appropriate regions for motion compensated prediction, and a new bit assignment algorithm in prediction error coding are also developed, Computer simulations are carried out to evaluate the coding efficiency at 9.6 kb/s. The result indicates that the objective and subjective qualities for decoded pictures are improved compared to those for the conventional block-based method, This algorithm is significantly effective for mobile communication.

关键词： image reconstruction image segmentation mobile communication motion compensation prediction theory video coding 9.6 kbit/s bit assignment algorithm coding efficiency computer simulations decoder encoder motion comp Video coding Prediction theory decoders image reconstruction image segmentation mobile communication ENCODER Motion compensation code efficiency

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A FREQUENCY SCALABLE coding SCHEME EMPLOYING PYRAMID AND SUBBAND TECHNIQUES

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS FOR VIDEO TECHNOLOGY 1994年第2期4卷 203-207页

作者： TAN, TK PANG, KK NGAN, KN Department of Electrical and Computer Systems Engineering Monash University VIC Australia

A flexible layered coding scheme using block-based DCT domain decimation has been simulated in software. A conditional replacement scheme which switches adaptively between the pyramid and subband approaches at the coefficient level was studied. Experimental results comparing the adaptive scheme against the pyramid approach show that this new approach increases the overall coding efficiency of the scalable coder by up to 1 dB.

关键词： block codes codecs discrete cosine transforms image coding image sequences telecommunications computing adaptive scheme block-based DCT domain decimation coding efficiency coefficient level conditional replacement scheme frequency scalable coding scheme codecs Block codes discrete cosine transforms image coding image sequences code efficiency Scalable coding telecommunication computing

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New Context-Adaptive Arithmetic coding Scheme for Lossless Bit Rate Reduction of Parametric Stereo in Enhanced aacPlus

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IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS 2018年第12期E101D卷 3258-3262页

作者： Pang, Hee-Suk Lim, Jun-seok Jin, Hyun-Young Sejong Univ Dept Elect Engn Seoul 05006 South Korea Seoul Natl Univ Dept Civil & Environm Engn Seoul 08826 South Korea

We propose a new context-adaptive arithmetic coding (CAAC) scheme for lossless bit rate reduction of parametric stereo (PS) in enhanced aacPlus. Based on the probability analysis of stereo parameters indexes in PS, we propose a stereo band-dependent CAAC scheme for PS. We also propose a new coding structure of the scheme which is simple but effective. The proposed scheme has normal and memory-reduced versions, which are superior to the original and conventional schemes and guarantees significant bit rate reduction of PS. The proposed scheme can be an alternative to the original PS coding scheme at low bit rate, where coding efficiency is very important.

关键词： context-adaptive arithmetic coding lossless bit rate reduction parametric stereo coding efficiency

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Modifications on morphology-based image coding

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ELECTRONICS LETTERS 2001年第7期37卷 421-422页

作者： Cai, ZH Subramanian, KR Cheng, TH Nanyang Technol Univ Sch EEE Singapore 639798 Singapore

An extension uf morphology-based image coding is presented. Tv achieve better coding efficiency neighbour coefficients are included into the significance m;ip predictor and different subband quantisers are employed to achieve the optimal quantiser fur each subband in a rare-distortion sense, Experimental results show. that about 0.4-0.7dB peak signal-to-noise ratio pain can be obtained.

关键词： coding efficiency rate-distortion sense Image and video coding peak signal-to-noise ratio gain significance map predictor image coding optimal quantiser morphology-based image coding quantisation (signal) subband quantisers image morphing neighbour coefficients Computer vision and image processing techniques mathematical morphology

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The noise cancelation effects caused by spike-frequency adaptation in single neurons

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NONLINEAR DYNAMICS 2020年第2期100卷 1825-1835页

作者： Zhang, Hui Yao, Jing Yu, Lianchun Zhang, Yiqi Taiyuan Univ Technol Coll Biomed Engn Taiyuan 030000 Peoples R China Lanzhou Univ Inst Theoret Phys Lanzhou 730000 Peoples R China Gansu Prov Peoples Hosp Anesthesia Surg Dept Lanzhou 730000 Peoples R China

Spike-frequency adaptation, which reduces the firing rate of a neuron during a constant stimulus, is a prominent property observed in many neurons. In this work, we studied the effects of the IAHP spiking adaptation on the information transmission and efficiency of the Morris-Lecar (ML) neuron model in the spike-timing coding scheme. We showed that this kind of adaptation caused non-trivial spiking dynamics when the input rate was high. Under the stimulation of high-rate inputs, although IAHP adaptation neurons could not outperform non-adaptation neurons in terms of information rate, IAHP adaptation neurons yielded higher coding efficiency than non-adaptation neurons. We also found that the noise could enlarge the range of input rates that the adaptation takes effect to enhance coding efficiency. Increasing the calcium-activated K+ current could also extend the range of input rates in which adaptation takes effect. Therefore, we argue that the IAHP adaptation mechanism may play a role of adaptive noise cancelation mechanism in neuronal information processing, i.e., it maintains information transmission when neurons receive low-rate inputs but substantially enhancing coding efficiency for high-rate inputs and highly noise environments by suppressing the spike train variability caused by the noise.

关键词： Morris-Lecar neuron model Spike-frequency adaptation Information entropy coding efficiency

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Dynamic threshold-based keyframe detection and its application in rate control

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IET IMAGE PROCESSING 2012年第7期6卷 986-995页

作者： Yao, W. Li, Z. Rahardja, S. Inst Infocomm Res Signal Proc Dept Singapore Singapore

This study proposes a new dynamic threshold model to detect keyframes for the coding of a video sequence. The proposed detection threshold is content adaptive which dynamically updates its value at each frame by taking into consideration both the statistical properties of the video sequence and the resolution as well as the quantisation parameters. The content variation metric used in the proposed detection method utilises the information that is already generated by the encoder during the encoding process and thus it makes the detection process fast. By applying the proposed scheme to rate control, the sizes of group of pictures are now adapted to the video content and it removes the temporal redundancy among different frames better, which transforms to the improvements on coding efficiency. The experimental results have shown that the proposed method achieves peak signal-to-noise ratio (PSNR) improvement.

关键词： image resolution statistical analysis temporal redundancy encoding process dynamic threshold model dynamic threshold-based keyframe detection coding efficiency Image and video coding rate control quantisation parameters quantisation (signal) encoder video coding image sequences peak signal-to-noise video resolution Video signal processing detection process content variation metric statistical properties video sequence coding PSNR Other topics in statistics

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MPEG-4 Video Verification Model: Status and directions

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INTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY 1997年第5期8卷 468-479页

作者： Moccagatta, I Talluri, R DSPS R&D Center 8830 LBJ Freeway MS 8374 Dallas TX 75243

This article describes the current status and future directions of the emerging ISO MPEG-4 audiovisual coding standard. The article first presents an overview of the different aspects of the standard and then focuses on the video coding aspects, The current status of the Video Verification Model (VM) (a completely defined encoder and decoder specification) is described in detail and its performance is presented. The new functionalities supported by this emerging standard and their potential applications are highlighted. (C) 1997 John Wiley & Sons, Inc.

关键词： MPEG-4 audiovisual coding video coding standard coding efficiency scalability error resilience content-based coding

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Adaptive block tree structure for video coding

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ETRI JOURNAL 2021年第2期43卷 313-323页

作者： Baek, Aram Gwon, Daehyeok Son, Sohee Lee, Jinho Kang, Jung-Won Kim, Hui Yong Choi, Haechul Hanbat Natl Univ Dept Multimedia Engn Daejeon South Korea Elect & Telecommun Res Inst Broadcasting Media Res Grp Daejeon South Korea Kyung Hee Univ Dept Comp Sci & Engn Yongin South Korea

The Joint Video Exploration Team (JVET) has studied future video coding (FVC) technologies with a potential compression capacity that significantly exceeds that of the high-efficiency video coding (HEVC) standard. The joint exploration test model (JEM), a common platform for the exploration of FVC technologies in the JVET, employs quadtree plus binary tree block partitioning, which enhances the flexibility of coding unit partitioning. Despite significant improvement in coding efficiency for chrominance achieved by separating luminance and chrominance tree structures in I slices, this approach has intrinsic drawbacks that result in the redundancy of block partitioning data. In this paper, an adaptive tree structure correlating luminance and chrominance of single and dual trees is presented. Our proposed method resulted in an average reduction of -0.24% in the Y Bjontegaard Delta rate relative to the intracoding of JEM 6.0 common test conditions.

关键词： block structure coding efficiency quadtree plus binary tree versatile video coding video coding

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RF Class-D amplification with bandpass sigma-delta modulator drive signals

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2006年第12期53卷 2507-2520页

作者： Johnson, Thomas Stapleton, Shawn P. PulseWave RF Austin TX 78746 USA Simon Fraser Univ Sch Engn Sci Burnaby BC V5A 1S6 Canada

The power efficiency of a RF Class-D amplifier with a bandpass sigma-delta (Sigma Delta M) modulator is analyzed for a complementary voltage-switched configuration. The modulator broadens the application of the amplifier to include signals with time varying envelopes such as W-CDMA. The addition of a modulator introduces new design variables which affect amplifier power efficiency including coding efficiency and the average transition frequency of the pulse train. Design equations are derived for the optimum load impedance, output power, conduction losses, capacitive switching losses, and drain efficiency. The general design equations are consistent with both periodic and aperiodic drive signals. Analytic and simulated results are compared for an example design with pseudomorphic high-electron mobility transistor and metal-semiconductor field-effect transistor switches with a fourth-order bandpass Sigma Delta M. The results show a drain efficiency of 52% with a 10-dB peak-to-average power ratio W-CDMA source signal at a frequency of 500 MHz.

关键词： bandpass sigma-delta (Sigma Delta) modulation Class-D amplifier coding efficiency RF power amplifier

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