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Biography

Dr. Yao-Jen Chang is a Senior Staff Engineer with Qualcomm since 2019. His recent and current research topics include high level syntax and low-level coding tools for MPEG video coding standards (e.g., VVC, HEVC, etc.) and the video coding methods beyond VVC. During 2017-2018, he built a video coding team at Foxconn, and led the team to develop next generation video coding technology toward VVC/H.266. Since 2013, he has actively participated in JVET and JCT-VC standardization meetings, and contributed 170 proposals to the meetings. He was a Vice-Chair and Coordinator in JVET and JCT-VC. During 2011-2013, he developed customized algorithm-level and ASIC-level IP for H.264/AVC and H.265/HEVC chips, which were sold to the businesses worldwide. He currently has hundreds of active patents worldwide, in which 70 are US patents. He has published 38 papers in the fields of video coding, machine learning, and communications. He was awarded "Outstanding Research Award" three times, respectively granted by Industrial Technology Research Institute, Interior Ministry of Taiwan, and National Central University. His current research interests include video/image coding tools, machine learning, and high level syntax for video coding standards.

Online Monitoring

RESeaRCH INTERESTS

Image and Video Coding

  • MPEG standard: VVC/H.266, HEVC/H.265, HEVC-SCC, H.264/AVC

  • Intra prediction: multiple reference line, secondary most probable mode, cross component prediction modes, multiple direct modes, DIMD, TIMD, intraTMP

  • Inter prediction: regular merge mode, merge with MVD, Affine merge mode, sub-block-based TMVP, geometric partition mode, combined inter-intra mode, overlapped block motion compensation, template matching merge mode

  • Screen content coding: palette coding, intra block copy, adaptive color transform

  • In-loop filter: sample adaptive offset

  • Encoder optimization: fast mode decision, fast CU size decision

High-Level Syntax

  • Subprofile and general constraint information (GCI)

  • Sub-picture and sub-bitstream extraction

  • Tile, picture headers, slice headers and WPP

  • Merging candidates number for regular,  subblock, IBC, and GEO merge modes

  • Wraparound motion compensation for 360 use case

  • Reference picture resampling functionality

  • Virtual boundary for 360 use case

Machine Learning

  • Supervised learning: neural network, fuzzy neural network, radial basis function

  • Unsupervised learning: clustering algorithm, rival penalized competitive learning

  • Global optimization: evolutionary algorithm, genetic algorithm

Research Experience

Qualcomm Incorporated | San Diego, CA, USA                                                                         Jan 2019 – Present

Senior Staff Engineer

Developed VVC standard from coding tools to high level syntax, and currently focusing on next generation video codec standard beyond VVC

  • Developed various intra and inter coding tools for ECM software improvement (next-generation video codec beyond VVC), and all were ADOPTED to reference software in the standard group

    • Intra coding tools: (1) SMPM; (2) CCCM template selection and multiple downsampling filters; (3) Decoder derived CCP; (4) Extended MRL; (5) Intra merge mode

    • Inter coding tools: (1) Type-based ARMC; (2) CIIP template matching; (3) GEO template matching; (4) OBMC

  • 28 high-level-syntax proposals for VVC standard as lead/1st author in JVET meeting: 39% adopted into VVC standard

  • 5 coding-tool-related proposals for VVC standard as lead/1st author in JVET meeting: 3 adopted into VVC standard

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Foxconn | Hsinchu, Taiwan                                                                                                         Jun 2017 – Jan 2019

Manager

Responsible for building video coding laboratories, talent recruitment, team management, whole R&D activities, IPR strategies, budget control, monthly report to chairman, and pushing the developed technologies into VVC standard

  • Led the team to achieve 1 or 2 patents per team member per meeting cycle, and 18% were evaluated as candidates of Standard Essential Patent (SEP) for VVC standard

  • Led the team to achieve at least one JVET technical proposal per team member per meeting cycle, and 15% proposals were adopted into VVC standard: Mainly focus on the topics of intra prediction and inter prediction

  • Collaborated with Sharp Japan and Sharp US teams (affiliated to Foxconn) to develop an enhanced video codec beyond HEVC and contributed 1 joint proposal to respond VVC Call for Proposal in JVET meeting (1st author from Foxconn side)

  • Assisted Foxconn on global video coding teams (Foxconn and Sharp) management and research plan for the success of next generation video coding standard

    • Advised top management on budget management of fiscal years for patent applications and machine setup, and strategies and quality improvement of patent applications

    • Negotiation with managers from global standard teams and global attorney teams to make consensus on the collaborations of research development, IPR strategies, and budget of fiscal years

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Industrial Technology Research Institute | Hsinchu, Taiwan                                                   Jan 2011 – Jun 2017

Senior Engineer and Project Leader

Developed VVC standard, HEVC-SCC standard, and customized H.264/HEVC encoder IPs

  • Project leader responsible for next generation video coding development and mentoring 1 project member to implement the algorithms, and internally awarded as the best project based on goal completeness (Top 5%)

  • Led 33 technical JVET/JCT-VC proposals in the area of intra prediction, palette coding, intra block copy, and adaptive color transform. 8 proposals adopted into specifications and/or reference software

  • Responsible for intra prediction and SAO algorithm designs to develop customized H.264 and HEVC encoder IPs

  • Received “Outstanding Research Award” twice issued by R&D Alternative Service Office of Interior Ministry of Taiwan (Top 0.05% researcher, 8th out of around 15,000 researchers national-wide) and ITRI (Top 1% engineer, 100/6000)

  • Committeeman of Patent Review Committee to review ITRI's patents internally

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National Chiao Tung University | Hsinchu, Taiwan                                                                 Oct 2013 – Mar 2014

Visiting Researcher

Appointed by Department Manager in ITRI ICL Division to visit the Laboratories of Prof. Wen-Hsiao Peng and Prof. Hsueh-Ming Hang to jointly develop screen content coding tools (Palette Coding and Intra Block Copy)

  • 1 joint NCTU & ITRI proposal (1st author from ITRI side) to respond HEVC SCC Call for Proposal in JCT-VC meeting

  • 4 jointly technical contributions to JCT-VC (all are 1st author)

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National Central University | Taoyuan, Taiwan                                                                       Aug 2004 – Dec 2010

Postgraduate (Ph.D. and Master degrees)

Developed various machine learning algorithms, e.g. fuzzy neural network, unsupervised learning, and evolutionary algorithm

  • 1 Book chapter, 5 journal papers, 11 conference papers (all are 1st author)

  • Received “Postgraduate Outstanding Research Award” (Top 0.6%, 7th/1177 including 377 doctorate postgraduates)

  • Received “Best Paper Award” issued by International Conference WCSP2009 (Top 0.9% paper, 10th/1023 submissions)

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