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A SCENE IS WORTH A THOUSAND FEATURES: FEED-FORWARD CAMERA LOCALIZATION FROM A COLLECTION OF IMAGE FEATURES

★ ★ ★ ★ ☆

Paper Summary

Paperzilla title
My Phone Knows Exactly Where I Am, Super Fast! (Even Better Than Before!)

This paper introduces FastForward, a novel computer vision method for quickly and accurately determining a camera's exact location and orientation in a 3D scene. By representing scenes as a sparse collection of image features and using a single feed-forward neural network pass, FastForward significantly reduces the time and resources required for mapping a scene while achieving state-of-the-art or comparable accuracy to existing methods across diverse indoor and outdoor environments. The approach also demonstrates robust generalization to unseen domains and varying scale ranges thanks to a scene and scale normalization technique.

Explain Like I'm Five

Imagine your phone instantly knowing its exact spot in the world by just looking around, much faster than before. This tech helps it do that using smart image features, even in tricky places.

Possible Conflicts of Interest

Axel Barroso-Laguna, Tommaso Cavallari, Victor Adrian Prisacariu, and Eric Brachmann are affiliated with Niantic Spatial. Niantic is a company specializing in Augmented Reality (AR) and mapping technologies. Visual localization is a core technology for AR applications, meaning the authors have a direct commercial interest in advancing this field.

Identified Limitations

Preprint Status
The paper is explicitly marked as "Preprint. Work in progress," indicating it has not yet undergone formal peer review, which is a crucial step for scientific validation.
Reliance on Image Retrieval
FastForward's strong performance, particularly its accuracy, heavily relies on a prior image retrieval step to select relevant mapping images. Without this step (e.g., random sampling of mapping images), the accuracy significantly drops, making it less robust in scenarios without pre-computed retrieval.
Computational Cost of Global Descriptors
While the retrieval index is fast to build, the time to extract global descriptors for a growing number of images is not negligible, which can still add to overall mapping overhead for very large datasets.
Pose Solver Runtime
The PnP-RANSAC pose solver, while standard, is currently the most time-consuming step in FastForward's localization process, taking up to 2.2 seconds on average in some scenes, indicating room for further optimization for truly real-time applications.
Scale Normalization Dependency
While the scale normalization strategy improves generalization, FastForward's accuracy can still be significantly affected without it, especially in large-scale outdoor scenes not explicitly covered during training.

Rating Explanation

The paper presents a novel and effective method that significantly reduces mapping preparation time while achieving state-of-the-art or competitive accuracy in visual localization across diverse environments. The approach demonstrates strong generalization capabilities. Although it is a preprint and has a clear conflict of interest, the technical contributions are substantial and address a significant practical problem in computer vision and AR. The identified weaknesses are acknowledged by the authors and are typical for ongoing research in this field.

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File Information

Original Title: A SCENE IS WORTH A THOUSAND FEATURES: FEED-FORWARD CAMERA LOCALIZATION FROM A COLLECTION OF IMAGE FEATURES
Uploaded: October 02, 2025 at 02:36 PM
Privacy: Public