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Ruojin Cai

14 accepted papers

2026

ArchSym: Detecting 3D-Grounded Architectural Symmetries in the Wild

CVPR 2026

Symmetry detection is a fundamental problem in computer vision, and symmetries serve as powerful priors for downstream tasks. However, existing learning-based methods for detecting 3D symmetries from single images have been almost exclusively trained and evaluated on object-centric or synthetic data

Cited by 0SourcecodeScholar
2025

Can Generative Video Models Help Pose Estimation?

CVPR 2025highlight

Pairwise pose estimation from images with little or no overlap is an open challenge in computer vision. Existing methods, even those trained on large-scale datasets, struggle in these scenarios due to the lack of identifiable correspondences or visual overlap. Inspired by the human ability to infer…

2025

Doppelgangers++: Improved Visual Disambiguation with Geometric 3D Features

CVPR 2025highlight

Accurate 3D reconstruction is frequently hindered by visual aliasing, where visually similar but distinct surfaces (aka, doppelgangers), are incorrectly matched. These spurious matches distort the structure-from-motion (SfM) process, leading to misplaced model elements and reduced accuracy. Prior ef…

Cited by 0SourcePDFScholar
2024

MegaScenes: Scene-Level View Synthesis at Scale

ECCV 2024poster

"Scene-level novel view synthesis (NVS) is fundamental to many vision and graphics applications. Recently, pose-conditioned diffusion models have led to significant progress by extracting 3D information from 2D foundation models, but these methods are limited by the lack of scene-level training data…

2023

Doppelgangers: Learning to Disambiguate Images of Similar Structures

ICCV 2023oral

We consider the visual disambiguation task of determining whether a pair of visually similar images depict the same or distinct 3D surfaces (e.g., the same or opposite sides of a symmetric building). Illusory image matches, where two images observe distinct but visually similar 3D surfaces, can be c…

Cited by 37PDFcodeScholar
2023

Neural Scene Chronology

CVPR 2023poster

In this work, we aim to reconstruct a time-varying 3D model, capable of rendering photo-realistic renderings with independent control of viewpoint, illumination, and time, from Internet photos of large-scale landmarks. The core challenges are twofold. First, different types of temporal changes, such…

2023

Tracking Everything Everywhere All at Once

ICCV 2023oral

We present a new test-time optimization method for estimating dense and long-range motion from a video sequence. Prior optical flow or particle video tracking algorithms typically operate within limited temporal windows, struggling to track through occlusions and maintain global consistency of estim…

Cited by 170PDFcodeScholar
2021

CondenseNet V2: Sparse Feature Reactivation for Deep Networks

CVPR 2021poster

Reusing features in deep networks through dense connectivity is an effective way to achieve high computational efficiency. The recent proposed CondenseNet has shown that this mechanism can be further improved if redundant features are removed. In this paper, we propose an alternative approach named…

Cited by 90PDFcodeScholar
2021

Extreme Rotation Estimation Using Dense Correlation Volumes

CVPR 2021poster

We present a technique for estimating the relative 3D rotation of an RGB image pair in an extreme setting, where the images have little or no overlap. We observe that, even when images do not overlap, there may be rich hidden cues as to their geometric relationship, such as light source directions,…

Cited by 48PDFcodeScholar
2020

Learning Gradient Fields for Shape Generation

ECCV 2020poster

In this work, we propose a novel technique to generate shapes from point cloud data. A point cloud can be viewed as samples from a distribution of 3D points whose density is concentrated near the surface of the shape. Point cloud generation thus amounts to moving randomly sampled points to high-dens…