Shoukun Sun
Shoukun Sun

Shoukun Sun, Ph.D.

Postdoctoral Researcher

Department of Computer Science, University of Idaho

I am a Postdoctoral Researcher in the Department of Computer Science at the University of Idaho, working with Xiaogang Ma. I build computer-vision and generative-AI methods for scientific imaging in settings where labels are scarce and images are very large: interactive segmentation that needs fewer clicks, diffusion models that generate and super-resolve images of arbitrary size, and training-free co-registration of satellite imagery.

I received my Ph.D. in Computer Science from the University of Idaho in 2025, advised by Min Xian, with a dissertation on deep learning for critical applications under sparse labeling. Much of that work was done with Idaho National Laboratory, on micrographs of irradiated nuclear fuel and on reactor event reports. The annotation platforms I built along the way, Auto-IS and SegMap, are in routine use at INL, the University of Idaho, NCEAS (UC Santa Barbara), and The Nature Conservancy.

Selected work

Auto-IS and SegMap: AI-assisted annotation platforms

Two annotation platforms built around my interactive-segmentation models, so that scientists label their own data with a few clicks instead of tracing outlines: Auto-IS for general imagery, with AI-assisted labelling, incremental training and group collaboration, and SegMap for remote sensing, as a QGIS plugin and a web app. In routine use at Idaho National Laboratory, the University of Idaho, NCEAS (UC Santa Barbara) and The Nature Conservancy, they underpin 12+ interdisciplinary projects and cut data-preparation time by up to 90%.

Interactive segmentation with fewer clicks

CFR-ICL trains an interactive segmentation model with an iterative click loss, the first loss to put the number of user clicks into the training objective, and refines masks at inference by running the same network over its own output. It set the state of the art on five benchmarks and needs 33% fewer clicks than the previous best to reach 0.95 IoU on Berkeley. It has since become the annotation engine behind our TRISO nuclear-fuel datasets.

Diffusion models beyond their native resolution

Averaging overlapping patches lets a small diffusion model paint a large image, but it quietly erodes the noise the sampler depends on, leaving seams and blur. Guided and variance-corrected fusion repairs this at no extra cost, taking a 512-pixel text-to-image model to seamless panoramas seven times wider and lowering FID from 11.19 to 4.02. InfScene-SR carries the same correction into super-resolution of arbitrarily large satellite scenes at constant GPU memory, within 0.003 IoU of native high-resolution imagery on a downstream mapping task.

Satellite image co-registration that does not fail silently

Alignment tools each assume one kind of motion and fail silently on the image pairs that break it. SCDF estimates a dense per-pixel displacement field with acceptance thresholds calibrated from the image pair itself: training-free, GPU-free, whole 8192-pixel scenes on one CPU core. On a new 584-pair benchmark over 60 sites worldwide it registers every pair without failure and lowers the best baseline's median error from 6.83 to 4.17 m.

Measuring fission-gas bubbles in irradiated nuclear fuel

With Idaho National Laboratory: a multitask network that separates touching fission-gas bubbles in electron micrographs of irradiated U-10Zr fuel, reaching 92% instance recall from only 827 annotated bubbles, against 54% for the thresholding it replaced. The same model then measured about 230,000 pores across an entire 6 mm fuel cross section, and the collaboration continues on TRISO particle fuel with RU-Net and the uncertainty-aware UA-Net.

All projects →

Selected publications

Self-Calibrating Dense Displacement Fields for Reliable Co-Registration of Large Optical Satellite Imagery

S. Sun, Z. Wang, S. Salati, J. Zhang, H. Wang, X. Ma

arXiv 2608.22300 · 2026

An Efficient Instance Segmentation Approach for Studying Fission Gas Bubbles in Irradiated Metallic Nuclear Fuel

S. Sun, F. Xu, L. Cai, D. Salvato, L. Capriotti, M. Xian, T. Yao

Scientific Reports · 2023

17 publications in total. Google Scholar → · Full list in the CV (PDF) →

News

Aug 2026

SCDF, training-free co-registration of large optical satellite imagery with a 584-pair benchmark, is on arXiv and under review at IEEE TGRS.

Apr 2026

UA-Net, an uncertainty-aware network for TRISO fuel image segmentation with Idaho National Laboratory, is on arXiv (co-first author).

Feb 2026

InfScene-SR, seamless diffusion super-resolution for arbitrarily large remote-sensing scenes, is on arXiv (code released).

Dec 2025

Started as a Postdoctoral Researcher in the Department of Computer Science at the University of Idaho.

Aug 2025

Received my Ph.D. in Computer Science from the University of Idaho. Dissertation: "Enhancing Deep Learning for Critical Applications with Sparse Labeling."

Dec 2024

Our paper on guided and variance-corrected fusion for large-content image generation was accepted at AAAI 2025.