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Zizheng Liu (刘子政)Video Codec Engineer  ZOOM Communications Inc. Location: Singapore Email: lzz8246 [AT] whu.edu.cn or lzz8246 [AT] gmail.com [Google Scholar] [LinkedIn] |
About Me
I am a Video Codec Engineer at ZOOM Singapore, where I focus on optimizing real-time video codecs.
Previously, I worked as a Senior Researcher at Tencent Media Lab and Tencent Video from July 2021 to September 2024, focusing on image and video compression. My work covered image/video codec optimization, Video Coding for Machines (VCM), and Neural Network-based Video Coding (NNVC).
I received my Ph.D. degree from the School of Remote Sensing and Information Engineering at Wuhan University, supervised by Prof. Zhenzhong Chen. My doctoral research focused on rate control, region-of-interest (ROI) coding, and perceptual optimization for video compression. I also have experience in image and video quality assessment.
Experience
Education
Publications
- Zizheng Liu, Xiang Pan, Yiming Li and Zhenzhong Chen: A Game Theory based CTU-level Bit Allocation Scheme for HEVC Region of Interest Coding, IEEE Transactions on Image Processing (TIP), 2021.
- Zizheng Liu, Xiang Pan, Yiming Li and Zhenzhong Chen: Stackelberg Game Based Rate Allocation for HEVC Region of Interest Coding, IEEE ICME 2018.
- Zizheng Liu, Zhenzhong Chen and Shan Liu: Two-stage Optimal Bit Allocation for HEVC Hierarchical Coding Structure, IEEE VCIP 2021.
- Jianghao Jia*, Zizheng Liu*, Xiaozhong Xu, Shan Liu and Zhenzhong Chen: Deep Reference Frame Interpolation based Inter Prediction Enhancement for Versatile Video Coding, IEEE VCIP 2022. (Equal contribution)
- Ding Ding, Zhenzhong Chen, Zizheng Liu, Xiaozhong Xu, Shan Liu: Hierarchical Image Feature Compression for Machines via Feature Sparsity Learning, IEEE Signal Processing Letters (SPL), 2024.
- Guangjie Ren, Zizheng Liu, Zhenzhong Chen, Shan Liu: Multi-Agent Reinforcement Learning based Bit Allocation for Gaming Video Coding, PCS 2024.
- Haiqiang Wang, Xin Zhao, Ding Ding, Xiang Pan, Zizheng Liu, Xiaozhong Xu, Shan Liu: Improvements of the BD-rate Metrics using Monotonic Curve-fitting Methods, PCS 2024.
- Weijie Bao, Jianghao Jia, Wenhui Meng, Zhenzhong Chen, Zizheng Liu, Xiaozhong Xu, Shan Liu: Towards Deep Reference Frame in Versatile Video Coding NNVC, IEEE VCIP 2023.
- Jianghao Jia, Yuantong Zhang, Han Zhu, Zhenzhong Chen, Zizheng Liu, Xiaozhong Xu, Shan Liu: Deep Reference Frame Generation Method for VVC Inter Prediction Enhancement, IEEE Transactions on Circuits and Systems for Video Technology (TCSVT), 2023.
- Huairui Wang, Guangjie Ren, Tong Ouyang, Junxi Zhang, Wenwei Han, Zizheng Liu and Zhenzhong Chen: Perceptual in-Loop Filter for Image and Video Compression, IEEE CVPR Workshops 2022.
- Guangjie Ren, Zizheng Liu, Zhenzhong Chen and Shan Liu: Reinforcement learning based ROI bit allocation for gaming video coding in VVC, IEEE VCIP 2021.
- Yingxue Zhang, Zizheng Liu, Zhenzhong Chen, Xiaozhong Xu and Shan Liu: No-reference Quality Assessment of Panoramic Video based on Spherical-domain Features, PCS 2021.
- Yiming Li, Zizheng Liu, Zhenzhong Chen and Shan Liu: Rate Control for Versatile Video Coding, IEEE ICIP 2020.
- Wei Wu, Zizheng Liu, Zhenzhong Chen and Shan Liu: No-Reference Video Quality Assessment based on Similarity Map Estimation, IEEE ICIP 2020.
- Yu Guo, Zizheng Liu, Zhenzhong Chen, Shan Liu: Deep Inter Coding with Interpolated Reference Frame for Hierarchical Coding Structure, IEEE VCIP 2020.
- Yingxue Zhang, Zizheng Liu, Wei Wu, Ruigang Yao, Zhenzhong Chen, Shan Liu: A Subjective Quality Assessment Database for Mobile Video Coding, IEEE MIPR 2020
- Yaosi Hu, Yingxue Zhang, Zizheng Liu, Zhenzhong Chen, Shan Liu: Subjective Study of Perceptual Quality for Micro-Video Applications, IEEE MIPR 2020.
- Yingxue Zhang, Yingbin Wang, Feiyang Liu, Zizheng Liu, Yiming Li, Daiqin Yang, Zhenzhong Chen: Subjective Panoramic Video Quality Assessment Database for Coding Applications, IEEE Transactions on Broadcasting (TB), 2018.
- Zhenzhong Chen, Yiming Li, Feiyang Liu, Zizheng Liu, Xiang Pan, Wanjie Sun, Yingbin Wang, Yan Zhou, Han Zhu and Shan Liu: CNN-Optimized Image Compression with Uncertainty based Resource Allocation, IEEE CVPR Workshops 2018.
Selected Standardization Proposals
- Zizheng Liu, Yiming Li, Zhenzhong Chen, Xiang Li, Shan Liu, "AHG10: Adaptive lambda ratio estimation for rate control in VVC", JVET-L0241, Oct. 2018, Macau, CN
- Xiang Li, Xiaozhong Xu, Shan Liu, Yiming Li, Zizheng Liu, Zhenzhong Chen, "Fix of Initial QP Signaling", JVET-L0553, Oct. 2018, Macao, CN (Adopted)
- Zizheng Liu, Zhenzhong Chen, Yiming Li, Yeqing Wu, Shan Liu, "AHG10: Quality dependency factor based rate control for VVC", JVET-M0600, Jan. 2019, Marrakech, MA (Adopted)
- Zizheng Liu, Zhenzhong Chen, Yiming Li, Xiang Li, Shan Liu, "AHG10: Enable Rate Control with In-Loop Reshaping", JVET-N0741, Mar. 2019, Geneva, CH (Adopted in software)
- Feiyang Liu, Zizheng Liu, Yiming Li, Zhenzhong Chen, "AHG10: Extension of rate control to support random access configuration with GOP size of 32", JVET-T0062, Oct. 2020, Online (Adopted in software)
- Zizheng Liu, Yiming Li, Zhenzhong Chen, Xiang Li, Shan Liu, "Improvements for HEVC rate control", JCTVC-AH0024, Jan. 2019, Marrakech, MA (Adopted)
- Zizheng Liu, Xiaozhong Xu, Shan Liu, Yu Guo, Zhenzhong Chen, "AHG11: NN-based Reference Frame Interpolation for VVC Hierarchical Coding Structure", JVET-X0060, Oct. 2021, Online
- Zizheng Liu, Xiaozhong Xu, Shan Liu, Yu Guo, Zhenzhong Chen, "AHG11: NN-based Reference Frame Interpolation for VVC Hierarchical Coding Structure", JVET-Y0096, Jan. 2022, Online
- Guangjie Ren, Jianghao Jia, Jiwei Wang, Zhenzhong Chen, Zizheng Liu, "AHG10: An improved VVC rate control scheme", JVET-Y0105, Jan. 2022, Online (Adopted)
- Zizheng Liu, Xiaozhong Xu, Shan Liu, Jianghao Jia, Zhenzhong Chen, "AHG11: Deep Reference Frame Generation for Inter Prediction Enhancement", JVET-AA0082, Jul. 2022, Online
- Jianghao Jia, Yuantong Zhang, Zhenzhong Chen, Zizheng Liu, Xiaozhong Xu, Shan Liu, "AHG11: Deep Reference Frame Generation for Inter Prediction Enhancement", JVET-AB0114, Oct. 2022, Mainz
- Jianghao Jia, Yuantong Zhang, Han Zhu, Zhenzhong Chen, Zizheng Liu, Xiaozhong Xu, Shan Liu, "AHG11: Deep Reference Frame Generation for Inter Prediction Enhancement", JVET-AC0114, Jan. 2023, Online
- Zizheng Liu, Yong Zhang, Roman Chernyak, Han Zhu, Xiaozhong Xu, Shan Liu, Jianghao Jia, Zhenzhong Chen, Min Woo Park, Kwang Pyo Choi, "[VCM] Response to VCM Call for Proposals - an EVC based solution", m60779, Oct. 2022, Mainz
- Zizheng Liu, Yong Zhang, Roman Chernyak, Han Zhu, Xiaozhong Xu, Shan Liu, Jianghao Jia, Zhenzhong Chen, "[VCM] Response to VCM Call for Proposals from Tencent and Wuhan University - an ECM based solution", m60780, Oct. 2022, Mainz
- Yong Zhang, Zizheng Liu, Han Zhu, Xiaozhong Xu, Shan Liu, Junxi Zhang, Jianghao Jia, Zhenzhong Chen, "[VCM] Response to VCM Call for Evidence from Tencent and Wuhan University - a Learning-based Feature Compression Framework", m60925, Oct. 2022, Mainz
- Zizheng Liu, Xiaozhong Xu, Shan Liu, "[VCM] CE4.1: Temporal resampling of m61542", m63100, Apr. 2023, Antalya (Adopted)
- Ding Ding, Xin Zhao, Zizheng Liu, Shan Liu "[VCM] Bitwise Efficiency: Truncating Bit Depth for Machine Video Coding", m65525, Oct. 2023, Hannover (Adopted)
- Ding Ding, Haiqiang Wang, Xin Zhao, Xiang Pan, Zizheng Liu, Xiaozhong Xu, Shan Liu, "[VCM] A Curve Fitting Approach to Transform Non-Monotonic Test Data for BD-Rate Calculation", m65531, Oct. 2023, Hannover (Adopted)
Projects
Real-time Video and Image Codec Optimization:
- AVS3
- VVC
- HEIF
Video Coding for Machines (VCM):
- The standardization activity in MPEG WG04 that aims at video compression for Machine communication.
- Implemented a spatial-temporal resampling based video coding framework for the response to Call for Proposals (CfP).
- Coordinates the Core Experiments on CE4 (Temporal resampling) and CE5 (Post filtering).
Neural Network based Video Coding (NNVC):
- The standardization activity in JVET that aims at neural network based video coding tools.
- Implemented a Neural network based reference frame generation framework for VVC Inter coding, -4.8% BD-rate savings achieved.
Versatile Video Coding (VVC):
- The standardization activity in JVET that aims at next-generation video coding standard, finalized at Jul. 2020.
- Implemented a quality dependency based rate control method, adopted in VTM 4.0/HM 16.20 and later versions.
- Maintain the rate control part in VTM and HM.
Audio Video Coding Standard (AVS):
- The standardization activity in China.
- Participated in developing Neural Network based video coding tools.
- Participated in developing NR/FR objective quality assessment model for mobile video.
- Participated in developing quality assessment method for Cloud Game services.
- Participated in developing subjective quality assessment standard for point cloud.
AVS2 Codec Optimization:
- Participated in the development of mavs2, a real-time AVS2 codec belonging to Tencent.
- Implemented rate control algorithm for this codec.
Trajectory-based Activity Pattern Analysis of Students (National Students' Innovation and Entrepreneurship Training Program):
- A project to analyze the activity pattern of students based on GPS trajectories.
- Implemented a GPS trajectory data drift processing algorithm.
- Implemented an activity pattern analysis method based on trajectory clustering.
Services
Journal and Conference Reviewer:
- IEEE Transactions on Image Processing (TIP)
- IEEE Transactions on Circuits and Systems for Video Technology (TCSVT)
- IEEE Transactions on Multimedia (TMM)
- Journal of Visual Communication and Image Representation (JVCIR)
- Data Compression Conference (DCC)
- Picture Coding Symposium (PCS)
Honors
- 2018, Best PSNR award in IEEE CVPR 2018 Challenge on Learned Image Compression (CLIC)
- 2017, Best Head Movement Prediction Student Prize in Salient360! IEEE ICME Grand Challenge
- 2016, Third-Class Prize in 3rd National Graduate Contest on Smart-City
- 2015, Top 1 in TRECVID SED SUB15-"PeopleSplitUp" task
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