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quantization parameter Cascading for Lossy Point Cloud Attribute Compression in G-PCC

APSIPA TRANSACTIONS ON SIGNAL AND INFORMATION PROCESSING 2025年第2期14卷

作者： Wei, Lei Zhu, Zhiwei Wang, Zhecheng Wan, Shuai Northwestern Polytech Univ Sch Elect & Informat Beijing Peoples R China Xian Int Univ Coll Engn Xian Peoples R China Qinghai Univ Sch Comp Technol & Applicat Xining Peoples R China Royal Melbourne Inst Technol RMIT Sch Engn Melbourne Australia

Region adaptive hierarchical transform (RAHT) is employed in G-PCC to make attribute compression more efficient. The performance of RAHT is closely related to the quantization parameter (QP), where applying different QPs to different transform depths is beneficial for coding efficiency. In this paper, QP cascading (QPC) is designed based on rate-distortion modelling. Firstly, the single-layer rate-quantization and distortion-quantization models are built by investigating the distribution of residuals. Later, the dependency of adjacent layers is studied to establish the rate-distortion model with dependency. Based on the proposed model, a rate-distortion optimization (RDO) guided QPC (O-QPC) and a fast implementation (F-QPC) are proposed. The experimental results verify the efficiency of the proposed methods. Compared with the G-PCC anchor, under the lossless geometry compression, O-QPC achieves an average of 1.5% performance gain in luma and nearly 13% gain in chroma, and F-QPC achieved an average performance gain of 1.0% in luma and almost 11% in chroma;Under the lossy geometry compression, O-QPC obtained an average of 3.9% gain in luma, and 13% gain in chroma, and F-QPC achieved an average of 3.4% gain in luma and nearly 12% gain in chroma. In particular, F-QPC achieves gains with almost no increase in complexity.

关键词： point cloud compression attribute RAHT quantization parameter

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HEVC quantization parameter selection algorithm based on inter-frame dependency

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MULTIMEDIA TOOLS AND APPLICATIONS 2020年第19-20期79卷 13951-13966页

作者： Huang, Xiaofeng Li, Dong Yin, Haibing Hangzhou Dianzi Univ 11582 St Hangzhou Hangzhou 310018 Peoples R China

Massive inter predictive modes are adopted in latest High Efficiency Video Coding (HEVC) standard to eliminate temporal redundancies, which results in stronger inter-frame dependency among neighboring frames than previous standards like H.264. The inter-frame dependency makes currently independent rate-distortion optimization (RDO) non-optimal any more. quantization parameter (QP) selection algorithm taking inter-frame dependency into consideration is supposed to optimize RDO based rate control greatly. According to our research, the inter-frame dependency is reflected by the linear relationship between QP change (Delta QP) and the resulting change of distortion (Delta D). An adaptive QP selection algorithm for global RDO is proposed based on the modeling function between Delta D and Delta QP in this paper. Firstly, based on intensive statistic analysis, three parameters (initial QP (QP over bar \documentclass[12pt]{minimal} the length of pictures of group (GOP), and the average of SATD of one frame) are used to formulate the relationship between Delta D and Delta QP. Secondly, the resulting rate change Delta R relative to Delta QP is also formulated similarly. Thirdly, optimized Lagrangian multiplier (lambda) is calculated with these two mathematic models. Finally, we refine QP values based on the optimized lambda in terms of dependent RDO. The experimental results show that the proposed frame-level QP selection algorithm can decrease Bj circle divide tegaard Delta BitRate (BD-BR) by about 1.62% at the random-access (RA) configuration and 1.13% at the low-delay (LD) configuration, respectively. At the same time, it doesn't increase complexity significantly.

关键词： High efficiency video coding Rate-distortion optimization Inter-frame dependency quantization parameter

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Near-Lossless Compression of Point Cloud Attribute Using quantization parameter Cascading and Rate-Distortion Optimization

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IEEE TRANSACTIONS ON MULTIMEDIA 2024年 26卷 3317-3330页

作者： Wei, Lei Wan, Shuai Wang, Zhecheng Yang, Fuzheng Northwestern Polytech Univ Sch Elect & Informat Xian 710129 Shaanxi Peoples R China RMIT Univ Sch Engn Melbourne Vic 3000 Australia Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Shaanxi Peoples R China

Near-lossless compression of point clouds is suitable for the application scenarios with low distortion tolerance and certain requirements on the rate. Near-lossless attribute compression usually adopts a level-of-detail structure, where the dependencies between the layers make it possible to improve the rate-distortion (R-D) performance by using different quantization parameters for different layers. In this work, a theoretical analysis of the dependencies between adjacent layers is carried out, based on which the dependent Distortion-quantization and Rate-quantization models are established for point cloud attribute compression. Then an algorithm for quantization parameter cascading based on R-D optimization is proposed and implemented for near-lossless compression of point cloud attributes. The experimental results show that the proposed method has a superior performance gain compared to state-of-the-art for the Hausdorff R-D performance. At the same time, the proposed method improves subjective quality and is well adapted to various categories of point clouds.

关键词： Point cloud compression near-lossless quantization parameter rate distortion optimization

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H.264/SVC parameter optimization based on quantization parameter, MGS fragmentation, and user bandwidth distribution

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EURASIP JOURNAL ON ADVANCES IN SIGNAL PROCESSING 2013年第1期2013卷 1-12页

作者： Chen, Xu Zhang, Ji-hong Liu, Wei Liang, Yong-sheng Feng, Ji-qiang Shenzhen Univ Sch Informat Engn Shenzhen Guangdong Peoples R China Shenzhen Inst Informat Technol Shenzhen Key Lab Visual Media Proc & Transmiss Shenzhen 518029 Guangdong Peoples R China

In the situation of limited bandwidth, how to improve the performance of scalable video coding plays an important role in video coding. The previously proposed scalable video coding optimization schemes concentrate on reducing coding computation or trying to achieve consistent video quality;however, the connections between coding scheme, transmission environments, and users' accesses manner were not jointly considered. This article proposes a H.264SVC (scalable video codec) parameter optimization scheme, which attempt to make full use of limited bandwidth, to achieve better peak signal-to-noise ratio, based on the joint measure of user bandwidth range and probability density distribution. This algorithm constructs a relationship map which consists of the bandwidth range of multiple users and the quantified quality increments measure, QP(e), in order to make effective use of the video coding bit-stream. A medium grain scalability fragmentation optimization algorithm is also presented with respect to user bandwidth probability density distribution, encoding bit rate, and scalability. Experiments on a public dataset show that this method provides significant average quality improvement for streaming video applications.

关键词： H.264/SVC Bandwidth distribution Quality increments quantization parameter MGS fragmentation

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MODELING THE BIT RATE OF H.264/AVC VIDEO ENCODING AS A FUNCTION OF quantization parameter, FRAME RATE AND GOP CHARACTERISTICS

MODELING THE BIT RATE OF H.264/AVC VIDEO ENCODING AS A FUNCT...

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IEEE International Conference on Multimedia and Expo Workshops (ICMEW)

作者： Lottermann, Christian Steinbach, Eckehard BMW Grp Munich Germany TUM Inst Media Technol Munich Germany

ISBN: (纸本)9781479947171

We present a novel analytical bit rate model for H.264/AVC video encoding which is based on the quantization parameter, the frame rate, the group-of-pictures length, the group-of-pictures structure and content-dependent parameters. The content-dependent parameters are described as a function of two standard video activity measures (temporal and spatial activity) which can easily be determined from the uncompressed video. Our bit rate model shows a Pearson correlation of more than 0.97 and a root-mean-square error of less than 2% as determined by statistical analysis.

关键词： Rate model H.264/AVC quantization parameter temporal resolution group-of-pictures

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ESTIMATION OF THE PRIMARY quantization parameter IN MPEG VIDEOS

ESTIMATION OF THE PRIMARY QUANTIZATION PARAMETER IN MPEG VID...

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IEEE International Conference on Visual Communications and Image Processing (VCIP)

作者： Wang, Wan Jiang, Xinghao Wang, Shilin Sun, Tanfeng Shanghai Jiao Tong Univ Sch Elect Informat & Elect Engn Shanghai 200030 Peoples R China

ISBN: (纸本)9781479902880

The advanced technology and sophisticated software have rendered audiovisual content exposed to forgery, inspiring the emergence of multimedia forensic research. Since video tampering may involve double compression, the analysis of compression history is of significance. In this paper, we consider the processing chains of two compression steps and propose an algorithm that aims at identifying the quantization parameter used in the previous coding process. The method relies on the fact that characteristic footprints can be observed under different relationships between quantization parameters of consecutive compression operations. Features are extracted from both Discrete Cosine Transform (DCT) coefficients and their differential counterparts to capture the statistical disturbance. Experimental results demonstrate the effectiveness of our method.

关键词： Video forensics double compression quantization parameter

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An Improved Initial quantization parameter Setting Algorithm of Rate Control Method for H264 Rate Control 18

An Improved Initial Quantization Parameter Setting Algorithm...

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18th IEEE International Conference on Communication Technology (IEEE ICCT)

作者： Han, Shuang Zhang, Wei Long Xiamen Inst Technol Xiamen Fujian Peoples R China

ISBN: (纸本)9781538676356

For h.264/AVC rate control algorithm, the initial QP estimation only depends on the number of bits per pixel, which is not accurate enough. In order to solve the problem that may cause frame skipping, decrease of average PSNR value and undesirable PSNR fluctuation, especially for complex video sequence and low target bit rate, this paper proposes an improved initial quantization parameter setting algorithm based on the complexity of intra frame and bits per pixel. The simulation results show that compared with the algorithms of H.264/AVC standard reference software JM8.6, the proposed algorithm enhances the PSNR and bit rate accuracy, and decreases the PSNR fluctuation.

关键词： H.264/AVC rate control quantization parameter

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A Novel Algorithm for Network-oriented quantization parameter Prediction Based on Neural Networks

A Novel Algorithm for Network-oriented Quantization Paramete...

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第一届国际测量仪器与测试自动化学术会议

作者： Ming Liang XieGuihai Xu Boyi Wang Xinfeng ( Mechanical Engineering College Shijiazhuang 050003 China) ( Beijing Institute System Engineering Beijing 100101 China)

＜正＞Neural networks are widely used in the prediction of network information. In this paper. we propose an algorithm based on the combination of neural networks and SRC scheme in MPEG-4 to predict the quantization parameter for each frame in network-oriented video coding. This novel algorithm is called NNSRC. NNSRC algorithm is implemented with two stages. The first stage contains the training process of the neural networks by the output of MPEG-4 SRC model. The second stage uses the trained neural networks alone to predict the adaptive quantization parameter according to available bandwidth computed from network traffic. The simulation experiment is made on the standard video testing sequence of MPEG. The results show that the NNSRC algorithm outperforms the MPEG-4 SRC scheme, which make video coder to achieve finer coding effect and higher network utilization compared to the MPEG-4 SRC scheme alone.

关键词： Neural networks quantization parameter network traffic.

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Predictive value of F-18 FDG PET/CT quantization parameters in diffuse large B cell lymphoma: a meta-analysis with 702 participants

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MEDICAL ONCOLOGY 2015年第1期32卷 1-10页

作者： Xie, Mixue Wu, Kefei Liu, Yan Jiang, Qi Xie, Yanhui Fudan Univ Huadong Hosp Dept Hematol Shanghai 200030 Peoples R China Fudan Univ Huadong Hosp Dept Gastroenterol Shanghai 200030 Peoples R China Second Mil Med Univ Peoples Liberat Army Shanghai Peoples R China

F-18 fluorodeoxyglucose (FDG) positron emission tomography/computerized tomography (PET/CT) is considered to be the most beneficial imaging method for staging patients with lymphoma. Whether maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) acquired from F-18 FDG PET/CT are predictors of prognosis of diffuse large B cell lymphoma (DLBCL) is controversial, with some studies concluding that it is and others concluding the opposite. Therefore, a systematic review was performed to explore the relationship of F-18 FDG PET/CT quantization parameters with the prognosis of DLBCL. Seven trials with a total of 703 DLBCL patients were included for analysis. Hazard ratios (HRs) for progression-free survival (PFS) and overall survival (OS), and odds ratios (ORs) for 3-year PFS and OS were pooled using the STATA package. Combined results suggested a strong link between the high SUVmax, MTV and TLG values and the poor 3-year PFS with ORs of 2.59, 3.69 and 2.29, respectively. Similarly, high MTV and TLG values unfavorably influenced the 3-year OS with ORs of 5.40 and 2.19, respectively. The pooled results also showed that high SUVmax and MTV were negative predictors of PFS with HRs of 1.61 (p = 0.038) and 2.18 (p = 0.000), respectively. The TLG value was not predictive of PFS. And for OS, only high MTV was a strong predictor of poor prognosis in DLBCL with HR 2.99 (p = 0.000). Our results suggested that SUVmax and MTV may be significant prognostic markers for PFS and MTV may be the only predictor for OS in DLBCL.

关键词： PET/CT Diffuse large B cell lymphoma quantization parameter Predictor Meta-analysis

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Predictive value of F-18 FDG PET/CT quantization parameters for progression-free survival in patients with diffuse large B-cell lymphoma

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HEMATOLOGY 2016年第2期21卷 99-105页

作者： Xie, Mixue Zhai, Weihao Cheng, Shiyu Zhang, Hongdi Xie, Yanhui He, Wei Fudan Univ Huadong Hosp Dept Hematol West Yanan Rd 221 Shanghai 200030 Peoples R China Fudan Univ Huadong Hosp Dept Nucl Med West Yanan Rd 221 Shanghai 200030 Peoples R China

Objectives: To evaluate the predictive significance of F-18 FDG PET/CT quantization parameters for progression-free survival (PFS) in patients with diffuse large B cell lymphoma (DLBCL) before chemotherapy. Methods: We conducted a retrospective study involving 60 patients with DLBCL between January 2010 and August 2014 who had undergone F-18 FDG PET/CT scan prior to treatment. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), total lesion glycolysis (TLG), and number of enlarged lymph nodes (>2 cm) were measured. The primary outcome measure was PFS. Spearman rank correlation analysis, univariate and multivariate Cox regression models, receiver operating characteristic (ROC) analysis, and Kaplan-Meir survival curves were used. Results: Spearman analysis determined that the MTV and TLG values were positively related to Ann Arbor stage, National Comprehensive Cancer Network International Prognostic Index (NCCN-IPI) score, and lactate dehydrogenase (LDH) level. The number of enlarged lymph nodes was positively related only to LDH level. The SUVmax value and clinical characteristics were not related. Univariate Cox regression determined that the MTV and TLG values, number of enlarged lymph nodes, and NCCN-IPI score were predictive factors. Multivariate Cox regression determined that the MTV and TLG values and number of enlarged lymph nodes predicted PFS independently of the NCCN-IPI score. The SUVmax value was not predictive of PFS. According to the cut-off determined from ROC analysis, lower MTV and TLG values were highly predictive of favorable PFS. Conclusions: In contrast to SUVmax, the MTV and TLG may be significant prognostic markers for PFS in DLBCL.

关键词： PET/CT Diffuse large B-cell lymphoma Progression-free survival quantization parameter Predictor

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