Junsoo Lee
Generative AI · Research & Serving

Junsoo Lee

AI Research Scientist — Generative Modeling & Software Engineering

NAVER WEBTOON AI  ·  M.S. in AI, KAIST

Seongnam, Republic of Korea

“Do it, like a Pro.”

01

About

AI Researcher & Engineer at NAVER WEBTOON, with an M.S. in AI from KAIST (advised by Prof. Jaegul Choo). I bridge the gap between research and production — designing AI systems from paper to deployment.

Over 4+ years I've built a unified AI platform serving generative models, designed multi-agent architectures, trained video foundation models, and shipped character generation to live consumer services. I've published at top-tier venues (AAAI, ECCV, ICCV, ACM MM), filed 3 patents, and reviewed 20+ papers in diffusion models, video generation and multimodal learning.

My current interests lie at the intersection of Robotics AI, Agentic AI, Generative Foundation Models, and Finance — building autonomous, intelligent systems that reason, act, and create value in the real world. I thrive in roles that demand both rigorous research thinking and hands-on engineering execution.

#AI Research #AI Engineering #Foundation Models #Agentic AI #Robotics AI #Multi-Agent Systems #Video Generation #Generative Models #Computer Vision #Machine Learning / Deep Learning #LLM #Finance #Python
02

Selected Work

Highlights from NAVER WEBTOON AI (2021–present) — across content generation and content understanding, from research to production serving.

🧩

AI Platform — Model Serving & Backend

6+ generative models · one platform

A unified platform for multi-model GPU serving, backend, RAG and auth — infrastructure to product APIs. An AI onboarding agent turns a model repo into a deployable service, driving the marginal cost of adding a model toward zero.

FastAPIGPU · multi-workervLLMRedis · queuemicroservices
🎬

Video Generation — Training & Data Pipeline

260K+ trained · 690K+ curated

End-to-end, anime-domain video generation on a "data is the model" premise — multi-stage DiT training over a reusable, large-scale curation engine (dedup, captioning, motion & aesthetic scoring) plus Blender-based 3D data generation.

DiTdata curationdistributed trainingoptical flowBlender
📖

Deep Story Understanding — Hierarchical RAG → LLM Wiki

1,000+ episode series

An LLM reads full web-novels and extracts characters, relationships, events, narrative and worldview into structured metadata — evolved from Hierarchical RAG (RAPTOR) to an LLM-Wiki multi-agent design, on traceable local models with a Kafka event-driven serving pipeline.

LangGraph · DeepAgentsRAPTORlocal LLM · vLLMKafkaOpenSearch
📑

PSD Parser & Comic Component Analysis

300K+ episodes · automated

Turns raw manuscripts into structured, machine-usable data: a production PSD engine (custom RGBA compositing) and a cascading CV pipeline (classify → segment → detect) — a platform asset feeding scroll-view, translation, animation and effect automation.

YOLOsegmentationsynthetic datalayer compositing
🎨

Video / Animation Colorization

validated by pro animators

Temporally-coherent colorization for animation via reference-based visual correspondence. Novel shadow-surface propagation and self-supervised (DINO) features won over initially-skeptical studio partners.

temporal propagationDINOself-supervisedGradio
🧬

Character Consistency & AI Video

shipped to a live service

Cascaded identity preservation (Style LoRA → IP-Adapter → FaceID) with per-character 3D pose DBs, and a text-to-video pipeline — among the org's first cases of generative AI serving end users directly.

SDXL · SVDIP-Adapter · FaceIDComfyUIControlNet3D · motion
🔊

Multi-Modal Audio / Sound Generation

4+ modalities · 58 TTS voices

Served and integrated audio generation across modalities — TTS with voice cloning (model-swappable for zero-downtime upgrades), text-to-music, text-to-sound and video-to-audio — all in one unified serving framework.

TTS · voice cloningtext-to-musicvideo-to-audiomodel distillation
Breadth

Research and large-scale serving across vision, video, audio and language — a full-stack multimodal generative-AI portfolio.

Shipped

Among the organization's first generative-AI features to serve end users directly, in a live consumer service.

Research

5 top-tier publications (AAAI'24, ECCV'24 ×2, ICCV'23, ACM.MM'23) and 3 patents in colorization & virtual try-on.

Scale

Platforms spanning 6+ served models, 260K+ training clips, and 1,000+ episode long-form series.

03

Selected Publications

Peer-reviewed work at top-tier venues. * denotes equal contribution. Full list on Google Scholar.

DreamStyler
AAAI 2024 DreamStyler: Paint by Style Inversion with Text-to-Image Diffusion Models
Namhyuk Ahn, Junsoo Lee, Chunggi Lee, Kunhee Kim, Daesik Kim, Seung-Hun Nam, Kibeom Hong
SAVE
ECCV 2024 SAVE: Protagonist Diversification with Structure-Agnostic Video Editing
Yeji Song, Wonsik Shin, Junsoo Lee, Jeesoo Kim, Nojun Kwak
TCAN
ECCV 2024 TCAN: Animating Human Images with Temporally Consistent Pose Guidance using Diffusion Models
Jeongho Kim*, Min-Jung Kim*, Junsoo Lee, Jaegul Choo
AesPA-Net
ICCV 2023 AesPA-Net: Aesthetic Pattern-Aware Style Transfer Networks
Kibeom Hong, Seogkyu Jeon, Junsoo Lee, Namhyuk Ahn, Kunhee Kim, Daesik Kim, Youngjung Uh, Hyeran Byun
FlatGAN
ACM MM 2023 FlatGAN: A Holistic Approach for Robust Flat-Coloring in High-Definition with Understanding Line Discontinuity
Han Kim*, Chunggi Lee*, Junsoo Lee*, Dohyun Kim, Ganggin Lee, Mohyun Oh, Daesik Kim
Guiding Colorization
WACV 2023 Guiding Users to Where to Give Color Hints for Efficient Interactive Sketch Colorization via Unsupervised Region Prioritization
Youngin Cho*, Junsoo Lee*, Soyoung Yang, Juntae Kim, Yeojeong Park, Haneol Lee, Jaegul Choo
AnimeCeleb
ECCV 2022 AnimeCeleb: Large-Scale Animation CelebHeads Dataset for Head Reenactment
Kangyeol Kim, Sunghyun Park, Jaeseong Lee, Sunghyo Chung, Junsoo Lee, Jaegul Choo
Vid-ODE
AAAI 2021 Vid-ODE: Continuous-Time Video Generation with Neural Ordinary Differential Equation
Sunghyun Park*, Kangyeol Kim*, Junsoo Lee, Jaegul Choo, Joonseok Lee, Sookyung Kim, Edward Choi
Reference-based Sketch Colorization
CVPR 2020 Reference-based Sketch Image Colorization using Augmented-Self Reference and Dense Semantic Correspondence
Junsoo Lee*, Eungyeup Kim*, Yunsung Lee, Dongjun Kim, Jaehyuk Chang, Jaegul Choo
MemoPainter
CVPR 2019 Coloring With Limited Data: Few-Shot Colorization via Memory-Augmented Networks
Seungjoo Yoo*, Hyojin Bahng*, Sunghyo Chung, Junsoo Lee, Jaehyuk Chang, Jaegul Choo
OCR
ACCV 2018 Simultaneous Recognition of Horizontal and Vertical Text in Natural Images
Chankyu Choi, Youngmin Yoon, Junsoo Lee, Junseok Kim

Also: DiffBlender, LPMM (CVPRW'23), Reference-based Image Composition (CVPRW'23), Decomposing Image Animation Identity, C2BIN, and Understanding Human-side Impact of Image Sequencing (CSCW'21) — see Scholar for the complete list.

04

Experience

Mar 2021 — Present

NAVER WEBTOON — Generative Model Research

Research Scientist (Full-time) · Gyeonggi, Korea
  • Lead research and production serving of multimodal generative AI (vision, video, audio).
  • Built the unified AI serving platform, video/audio pipelines, and multi-agent RAG systems.
  • 5 top-tier publications, 3 patents, 20+ paper reviews/year, industry–academia collaboration.
Aug 2020 — Feb 2021

KAKAO Enterprise — AI Lab

Research Intern (Full-time)
  • Self-supervised & semi-supervised visual representation learning from large-scale unlabeled images.
Oct 2018 — Feb 2019

NAVER WEBTOON — AI Research

Full-time Researcher
  • Organizer for a comic-domain deep-learning workshop at ICCV'19.
  • Visual-language research: comic panel reordering as a scene-understanding problem.
Apr 2018 — Oct 2018

NAVER — Papago OCR

Research Intern (Full-time)
  • Synthetic data generation to improve OCR for Papago machine translation.
  • Joint text recognition & segmentation via multitask learning and GANs.
Jan 2018 — Apr 2018

Xinapse — NLP Engineering

Research Intern (Full-time)
  • Sentence-level user-intent classifier with topic modeling; production chatbot backend.
Jul 2016 — Jul 2017

Software Maestro (7th)

Software & Machine Learning Engineer · top 10% final certification
  • CCTV video-analysis system auto-capturing objects across frames to cut search time.
05

Education

KAIST Mar 2019 — Feb 2021
M.S. in Artificial Intelligence · Advisor: Prof. Jaegul Choo · Daejeon, Korea
Soongsil University Mar 2013 — Aug 2018
B.S. in Computer Science & Engineering · Seoul, Korea
06

Talks

DIT Center, SAMSUNG ElectronicsJul 2020
AI Seminar for Recent Image Generation — history of image generation & colorization.
HYUNDAI Motor CorporationJul 2020
Domestic AI Laboratories Clustering — lab publications overview.
07

Skills

Languages
PythonJavaC / C++JavaScript
ML / Modeling
PyTorchDiffusion ModelsVideo GenerationStyle TransferSelf-supervisedMultimodal
Serving / Infra
FastAPIDockerRedisGPU inferencevLLMPostgreSQLMongoDBOpenSearch
Agents / Retrieval
LangGraphDeepAgentsHierarchical RAGlocal LLM servingtool orchestration
Creative Tooling
ComfyUIControlNetLoRABlender