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Dylan Campbell

26 accepted papers

2025

Believing is Seeing: Unobserved Object Detection using Generative Models

CVPR 2025poster

Can objects that are not visible in an image---but are in the vicinity of the camera---be detected? This study introduces the novel tasks of 2D, 2.5D and 3D unobserved object detection for predicting the location of nearby objects that are occluded or lie outside the image frame. We adapt several s…

2025

LMOD: A Large Multimodal Ophthalmology Dataset and Benchmark for Large Vision-Language Models

NAACL 2025findings

The prevalence of vision-threatening eye diseases is a significant global burden, with many cases remaining undiagnosed or diagnosed too late for effective treatment. Large vision-language models (LVLMs) have the potential to assist in understanding anatomical information, diagnosing eye diseases, a…

Cited by 6SourcePDFScholar
2025

Leaps and Bounds: An Improved Point Cloud Winding Number Formulation for Fast Normal Estimation and Surface Reconstruction

ICCV 2025poster

Recent methods for point cloud surface normal estimation predominantly use the generalized winding number field induced by the normals. Optimizing the field towards satisfying desired properties, such as the input points being on the surface defined by the field, provides a principled way to obtain…

Cited by 0SourcePDFScholar
2025

Pos3R: 6D Pose Estimation for Unseen Objects Made Easy

CVPR 2025poster

Foundation models have significantly reduced the need for task-specific training, while also enhancing generalizability. However, state-of-the-art 6D pose estimators either require further training with pose supervision or neglect advances obtainable from 3D foundation models. The latter is a missed…

Cited by 0SourcePDFScholar
2025

Probability Density Geodesics in Image Diffusion Latent Space

CVPR 2025poster

Diffusion models indirectly estimate the probability density over a data space, which can be used to study its structure. In this work, we show that geodesics can be computed in diffusion latent space, where the norm induced by the spatially-varying inner product is inversely proportional to the pro…

2025

Ranked from Within: Ranking Large Multimodal Models Without Labels

ICML 2025poster

Can the relative performance of a pre-trained large multimodal model (LMM) be predicted without access to labels? As LMMs proliferate, it becomes increasingly important to develop efficient ways to choose between them when faced with new data or tasks. The usual approach does the equivalent of givin…

Cited by 0SourcePDFScholar
2024

An Empirical Study Into What Matters for Calibrating Vision-Language Models

ICML 2024poster

Vision-Language Models (VLMs) have emerged as the dominant approach for zero-shot recognition, adept at handling diverse scenarios and significant distribution changes. However, their deployment in risk-sensitive areas requires a deeper understanding of their uncertainty estimation capabilities, a r…

Cited by 8SourcePDFScholar
2024

Differentiable Neural Surface Refinement for Modeling Transparent Objects

CVPR 2024poster

Neural implicit surface reconstruction leveraging volume rendering has led to significant advances in multi-view reconstruction. However results for transparent objects can be very poor primarily because the rendering function fails to account for the intricate light transport induced by refraction…

Cited by 1SourcePDFScholar
2024

IMPUS: Image Morphing with Perceptually-Uniform Sampling Using Diffusion Models

ICLR 2024poster

We present a diffusion-based image morphing approach with perceptually-uniform sampling (IMPUS) that produces smooth, direct and realistic interpolations given an image pair. The embeddings of two images may lie on distinct conditioned distributions of a latent diffusion model, especially when they…

2024

LoCo: Learning 3D Location-Consistent Image Features with a Memory-Efficient Ranking Loss

NeurIPS 2024poster

Image feature extractors are rendered substantially more useful if different views of the same 3D location yield similar features while still being distinct from other locations. A feature extractor that achieves this goal even under significant viewpoint changes must recognise not just semantic cat…

Cited by 0SourcePDFScholar
2024

Small Steps and Level Sets: Fitting Neural Surface Models with Point Guidance

CVPR 2024poster

A neural signed distance function (SDF) is a convenient shape representation for many tasks such as surface reconstruction editing and generation. However neural SDFs are difficult to fit to raw point clouds such as those sampled from the surface of a shape by a scanner. A major issue occurs when th…

2023

Exploring Predicate Visual Context in Detecting of Human-Object Interactions

ICCV 2023poster

Recently, the DETR framework has emerged as the dominant approach for human--object interaction (HOI) research. In particular, two-stage transformer-based HOI detectors are amongst the most performant and training-efficient approaches. However, these often condition HOI classification on object feat…

Cited by 50PDFcodeScholar
2022

Efficient Two-Stage Detection of Human-Object Interactions With a Novel Unary-Pairwise Transformer

CVPR 2022poster

Recent developments in transformer models for visual data have led to significant improvements in recognition and detection tasks. In particular, using learnable queries in place of region proposals has given rise to a new class of one-stage detection models, spearheaded by the Detection Transformer…

Cited by 143PDFcodeScholar
2022

SNeS: Learning Probably Symmetric Neural Surfaces from Incomplete Data

ECCV 2022poster

"We present a method for the accurate 3D reconstruction of partly-symmetric objects. We build on the strengths of recent advances in neural reconstruction and rendering such as Neural Radiance Fields (NeRF). A major shortcomings of such approaches is that they fail to reconstruct any part of the obj…

2021

Keeping Your Eye on the Ball: Trajectory Attention in Video Transformers

NeurIPS 2021oral

In video transformers, the time dimension is often treated in the same way as the two spatial dimensions. However, in a scene where objects or the camera may move, a physical point imaged at one location in frame $t$ may be entirely unrelated to what is found at that location in frame $t+k$. These t…

2021

Learning To Estimate Hidden Motions With Global Motion Aggregation

ICCV 2021poster

Occlusions pose a significant challenge to optical flow algorithms that rely on local evidences. We consider an occluded point to be one that is imaged in the first frame but not in the next, a slight overloading of the standard definition since it also includes points that move out-of-frame. Estima…

Cited by 408PDFcodeScholar
2021

Spatially Conditioned Graphs for Detecting Human-Object Interactions

ICCV 2021poster

We address the problem of detecting human-object interactions in images using graphical neural networks. Unlike conventional methods, where nodes send scaled but otherwise identical messages to each of their neighbours, we propose to condition messages between pairs of nodes on their spatial relatio…

Cited by 147PDFcodeScholar
2020

Deep Novel View Synthesis from Colored 3D Point Clouds

ECCV 2020poster

We propose a new deep neural network which takes a colored 3D point cloud of a scene, and directly synthesizes a photo-realistic image from an arbitrary viewpoint. Key contributions of this work include a deep point feature extraction module, an image synthesis module, and an image refinement module…

2020

Solving the Blind Perspective-n-Point Problem End-To-End With Robust Differentiable Geometric Optimization

ECCV 2020poster

Blind Perspective-n-Point (PnP) is the problem of estimating the position and orientation of a camera relative to a scene, given 2D image points and 3D scene points, without prior knowledge of the 2D-3D correspondences. Solving for pose and correspondences simultaneously is extremely challenging sin…

2020

Where Am I Looking At? Joint Location and Orientation Estimation by Cross-View Matching

CVPR 2020poster

Cross-view geo-localization is the problem of estimating the position and orientation (latitude, longitude and azimuth angle) of a camera at ground level given a large-scale database of geo-tagged aerial (eg., satellite) images. Existing approaches treat the task as a pure location estimation proble…

Cited by 213PDFcodeScholar
2019

The Alignment of the Spheres: Globally-Optimal Spherical Mixture Alignment for Camera Pose Estimation

CVPR 2019poster

Determining the position and orientation of a calibrated camera from a single image with respect to a 3D model is an essential task for many applications. When 2D-3D correspondences can be obtained reliably, perspective-n-point solvers can be used to recover the camera pose. However, without the pos…

Cited by 42PDFScholar
2017

Globally-Optimal Inlier Set Maximisation for Simultaneous Camera Pose and Feature Correspondence

ICCV 2017oral

Estimating the 6-DoF pose of a camera from a single image relative to a pre-computed 3D point-set is an important task for many computer vision applications. Perspective-n-Point (PnP) solvers are routinely used for camera pose estimation, provided that a good quality set of 2D-3D feature corresponde…

Cited by 73PDFScholar