My research focuses on building controllable, identity-preserving generative models for image editing, composition, and restoration. I am particularly interested in problems where generation operates on real images, requiring outputs to remain consistent, recognizable, and faithful under diverse, real-world conditions.

My work spans early research exploration to tech transfer into real products, including large-scale data curation, pipeline design, and deployment in production settings. At Adobe, I led the development of generative harmonization technology from prototype to production, shipped as Harmonize in Photoshop, enabling photorealistic compositing at scale.

Currently, my research explores personalized generative models for photography, preserving identity across editing and generation.

See full publication list at Google Scholar.

SynthLight: Portrait Relighting with Diffusion Model by Learning to Re-render Synthetic Faces
CVPR 2025

SynthLight: Portrait Relighting with Diffusion Model by Learning to Re-render Synthetic Faces

Sumit Chaturvedi, Mengwei Ren, Yannick Hold-Geoffroy, Jingyuan Liu, Julie Dorsey, Zhixin Shu

We explore portrait relighting by training a diffusion model to re-render synthetic faces.

Generative Portrait Shadow Removal
SIGGRAPH Asia 2024

Generative Portrait Shadow Removal

Jae Shin Yoon, Zhixin Shu, Mengwei Ren, Xuaner Zhang, Yannick Hold-Geoffroy, Krishna Kumar Singh, He Zhang

A high-fidelity portrait shadow removal model that effectively enhances portraits by predicting appearance under disturbing shadows and highlights.

Relightful Harmonization: Lighting-aware Portrait Background Replacement
CVPR 2024

Relightful Harmonization: Lighting-aware Portrait Background Replacement

Mengwei Ren, Wei Xiong, Jae Shin Yoon, Zhixin Shu, Jianming Zhang, HyunJoon Jung, Guido Gerig, He Zhang

A lighting-aware diffusion model designed to seamlessly harmonize sophisticated lighting effects for foreground portraits using any background image.

Multiscale Structure Guided Diffusion for Image Deblurring
ICCV 2023

Multiscale Structure Guided Diffusion for Image Deblurring

Mengwei Ren, Mauricio Delbracio, Hossein Talebi, Guido Gerig, Peyman Milanfar

A simple yet effective structure guidance for image-conditioned diffusion models that leads to significantly better visual quality on unseen images.

Keypoint-Augmented Self-Supervised Learning for Medical Image Segmentation with Limited Annotation
NeurIPS 2023

Keypoint-Augmented Self-Supervised Learning for Medical Image Segmentation with Limited Annotation

Zhangsihao Yang*, Mengwei Ren*, Kaize Ding, Guido Gerig, Yalin Wang

A keypoint-augmented fusion layer that extracts representations preserving both short- and long-range self-attention in a self-supervised manner.

Local Spatiotemporal Representation Learning for Longitudinally-consistent Neuroimage Analysis
NeurIPS (oral) 2022

Local Spatiotemporal Representation Learning for Longitudinally-consistent Neuroimage Analysis

Mengwei Ren, Neel Dey, Martin A. Styner, Kelly N. Botteron, Guido Gerig

A local and multi-scale spatiotemporal representation learning method for image-to-image architectures trained on longitudinal images.

Segmentation-Renormalized Deep Feature Modulation for Unpaired Image Harmonization
IEEE Trans. Medical Imaging 2021

Segmentation-Renormalized Deep Feature Modulation for Unpaired Image Harmonization

Mengwei Ren, Neel Dey, James Fishbaugh, Guido Gerig

A segmentation-renormalized image translation framework to reduce inter-scanner heterogeneity while preserving anatomical layout.

Q-space Conditioned Translation Networks for Directional Synthesis of Diffusion Weighted Images from Multi-modal Structural MRI
MICCAI (oral) 2021

Q-space Conditioned Translation Networks for Directional Synthesis of Diffusion Weighted Images from Multi-modal Structural MRI

Mengwei Ren, Heejong Kim, Neel Dey, Guido Gerig

A generative adversarial translation framework for high-quality DW image estimation with arbitrary Q-space sampling given commonly acquired structural images.

Generative Adversarial Registration for Improved Conditional Deformable Templates
ICCV 2021

Generative Adversarial Registration for Improved Conditional Deformable Templates

Neel Dey, Mengwei Ren, Adrian Dalca, Guido Gerig

A generative adversarial registration framework conditioned on flexible image covariates for improved deformable template estimation.