Erich Liang will present his General Exam "ChangeIn: A Benchmark for Self-Calibration of Dynamic Intrinsics of Video Cameras" on Monday, May 5, 2025 at 10:30 AM in FC 202 and via zoom. Zoom link: https://princeton.zoom.us/j/8238970644 Committee Members: Jia Deng (advisor), Szymon Rusinkiewicz , Ellen Zhong Abstract: Accurately tracking camera intrinsics is crucial for achieving 3D understanding from 2D video. However, most 3D algorithms assume that camera intrinsics stay constant throughout a video, which is often not true for many real-world in-the-wild videos. A major obstacle in this field is a lack of dynamic camera intrinsics benchmarks--existing benchmarks typically offer limited diversity in scene content and intrinsics variation, and none provide per-frame intrinsic changes for consecutive video frames. In this paper, we present ChangeIn, a real-world benchmark that provides per-frame ground truth intrinsics annotations for videos with dynamic intrinsics. Compared to prior benchmarks, ChangeIn captures a wider range of intrinsic variations and scene diversity, featuring 143K annotated frames from 386 high-resolution indoor and outdoor videos with dynamic camera intrinsics. To ensure accurate per-frame intrinsics, we build a comprehensive look-up table of calibration experiments and extend the Kalibr toolbox to improve its accuracy and robustness. Using our benchmark, we evaluate existing baseline methods for predicting camera intrinsics and find that most struggle to achieve accurate predictions on videos with dynamic intrinsics. Reading List: https://docs.google.com/document/d/1pu3P9hWcthJRMvBSssPqWLYiq3QZCVfa4p_v50Jf... Everyone is invited to attend the talk, and those faculty wishing to remain for the oral exam following are welcome to do so.