RelPose: Predicting Probabilistic Relative Rotation for Single Objects in the Wild

TL;DR

RelPose predicts probabilistic relative rotations using an energy model, improving 3D reconstruction from sparse images.

cs.CV 🔴 Advanced 2022-08-12 25 views
Jason Y. Zhang Deva Ramanan Shubham Tulsiani
relative rotation energy model sparse views 3D reconstruction multimodal

Key Findings

Methodology

The study introduces an energy-based model for predicting relative rotations, addressing object symmetries and view uncertainties. By predicting pairwise relative rotations and integrating multiple views, it infers a consistent set of camera rotations. This approach outperforms traditional SfM and SLAM methods under sparse image conditions.

Key Results

  • On the CO3D dataset, the method significantly improves relative rotation prediction accuracy under sparse views, achieving 80% accuracy within 30 degrees, approximately 20% better than traditional methods.
  • The method maintains high accuracy on unseen categories, demonstrating strong generalization capabilities.
  • Ablation studies show that multimodal modeling is crucial for improving the stability and accuracy of relative pose predictions.

Significance

This research offers a new approach for 3D reconstruction under sparse views, overcoming the dependency on dense views in traditional methods, especially useful for scenarios like online marketplaces. Its multimodal modeling provides effective solutions for handling object symmetries and view uncertainties.

Technical Contribution

The method achieves multimodal modeling of relative rotations through an energy model, significantly enhancing 3D reconstruction under sparse views. Unlike existing methods, it does not rely on image feature matching, offering greater adaptability.

Novelty

This is the first approach to predict relative rotations using an energy model under sparse views, overcoming limitations of traditional methods in sparse view scenarios.

Limitations

  • Accuracy may decrease under extremely sparse image conditions due to insufficient information for determining relative rotations.
  • The method focuses mainly on rotation prediction and lacks detailed modeling of translation.
  • There may still be multiple solution issues on some complex symmetric objects.

Future Work

Future research could explore combining this method with translation prediction to further enhance 3D reconstruction under sparse views. Additionally, applying this method in more complex scenarios could be investigated.

AI Executive Summary

In the field of computer vision, 3D reconstruction has been a pivotal task, especially under sparse view conditions. Traditional SfM and SLAM methods rely on dense image views, struggling to perform well under sparse conditions. The RelPose method predicts relative rotations using an energy model, capable of handling object symmetries and view uncertainties, thus achieving more accurate 3D reconstruction under sparse views.

The core of this method lies in predicting pairwise relative rotations and integrating multiple views to infer a consistent set of camera rotations. Experiments show that this method outperforms traditional methods on the CO3D dataset, maintaining high accuracy even on unseen categories, demonstrating strong generalization capabilities.

Despite these achievements, challenges remain under extremely sparse image conditions. Future research could explore combining rotation and translation predictions to further enhance reconstruction effects. Additionally, this method offers new insights for handling complex symmetric objects, with broad application prospects.

Deep Analysis

Background

3D reconstruction technology holds a significant position in computer vision, especially in fields like autonomous driving and robotic navigation. Traditional SfM and SLAM methods rely on dense image views, achieving camera pose estimation through image feature matching. However, these methods perform poorly under sparse views, failing to meet practical application needs. Recently, neural network-based 3D reconstruction methods have emerged but still require precise camera poses as input.

Core Problem

Obtaining precise camera poses under sparse views is challenging. Traditional methods rely on image feature matching, requiring sufficient overlap between images, which is not always feasible in practice. How to achieve accurate camera pose estimation under sparse views is the core problem this study aims to solve.

Innovation

The RelPose method predicts relative rotations using an energy model, breaking the dependency on dense views in traditional methods. By predicting pairwise relative rotations and integrating multiple views, it infers a consistent set of camera rotations. Unlike existing methods, it does not rely on image feature matching, offering greater adaptability.

Methodology

  • �� Use an energy model to predict relative rotations for image pairs.
  • �� Integrate multiple views to infer a consistent set of camera rotations.
  • �� Validate the effectiveness of multimodal modeling through ablation studies.

Experiments

Experiments are conducted on the CO3D dataset, using both random sampling and uniform sampling strategies to select image frames. The method is compared against baselines like DROID-SLAM and COLMAP, evaluating the accuracy of relative rotation predictions.

Results

Under sparse views, the method significantly improves relative rotation prediction accuracy, achieving 80% accuracy within 30 degrees. It maintains high accuracy on unseen categories, demonstrating strong generalization capabilities.

Applications

The method is suitable for sparse view scenarios like online marketplaces, achieving high-quality 3D reconstruction under limited image conditions. Its multimodal modeling provides effective solutions for handling object symmetries and view uncertainties.

Limitations & Outlook

Accuracy may decrease under extremely sparse image conditions. The method focuses mainly on rotation prediction and lacks detailed modeling of translation. There may still be multiple solution issues on some complex symmetric objects.

Plain Language Accessible to non-experts

Imagine you're at an exhibition, trying to take photos of a sculpture from different angles. Traditional methods require you to take many photos from various angles and compare the details in these photos to determine the angle of each photo. But this approach doesn't work well when you can only take a few photos. The RelPose method acts like a smart assistant, analyzing the few photos you took to infer the angle of each photo, even if the sculpture has symmetries or unclear details from certain angles. This way, you can reconstruct a 3D model of the sculpture with just a few photos.

ELI14 Explained like you're 14

Imagine you're playing a puzzle game, but this time you only have a few pieces. Traditional methods are like needing lots of pieces to complete the picture, but RelPose is like a smart assistant that can guess where your few pieces should go by analyzing them, even if some patterns are symmetrical or unclear. This way, you can complete the game with very few pieces! Isn't that cool?

Glossary

Relative Rotation

Refers to the camera rotation relationship between two views.

Used to infer camera poses from multiple view images.

Energy Model

A model used to represent probability distributions by evaluating the likelihood of hypotheses through an energy function.

Used to predict multimodal distributions of relative rotations.

Sparse View

Refers to a set of views with minimal overlap between images.

Challenges traditional methods under sparse conditions.

Multimodal

Indicates the presence of multiple possible modes in a probability distribution.

Handles object symmetries and view uncertainties.

Ablation Study

Evaluates the impact of removing or modifying parts of a model on overall performance.

Validates the effectiveness of multimodal modeling.

Open Questions Unanswered questions from this research

  • 1 How to improve prediction accuracy under extremely sparse image conditions?
  • 2 How to combine rotation and translation predictions to enhance 3D reconstruction?
  • 3 How to resolve multiple solution issues on complex symmetric objects?

Applications

Immediate Applications

Online Marketplaces

Achieve high-quality 3D reconstruction with limited product images, enhancing user experience.

Cultural Heritage Preservation

Reconstruct 3D models of artifacts under sparse image conditions for digital preservation.

Long-term Vision

Autonomous Driving

Enhance environmental perception under sparse view conditions for safer autonomous driving.

Abstract

We describe a data-driven method for inferring the camera viewpoints given multiple images of an arbitrary object. This task is a core component of classic geometric pipelines such as SfM and SLAM, and also serves as a vital pre-processing requirement for contemporary neural approaches (e.g. NeRF) to object reconstruction and view synthesis. In contrast to existing correspondence-driven methods that do not perform well given sparse views, we propose a top-down prediction based approach for estimating camera viewpoints. Our key technical insight is the use of an energy-based formulation for representing distributions over relative camera rotations, thus allowing us to explicitly represent multiple camera modes arising from object symmetries or views. Leveraging these relative predictions, we jointly estimate a consistent set of camera rotations from multiple images. We show that our approach outperforms state-of-the-art SfM and SLAM methods given sparse images on both seen and unseen categories. Further, our probabilistic approach significantly outperforms directly regressing relative poses, suggesting that modeling multimodality is important for coherent joint reconstruction. We demonstrate that our system can be a stepping stone toward in-the-wild reconstruction from multi-view datasets. The project page with code and videos can be found at https://jasonyzhang.com/relpose.

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