GT-Loc: Unifying When and Where in Images Through a Joint Embedding Space

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Shatwell, David G., Dave, Ishan Rajendrakumar, Swetha, Sirnam, Shah, Mubarak
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866916864523763712
author Shatwell, David G.
Dave, Ishan Rajendrakumar
Swetha, Sirnam
Shah, Mubarak
author_facet Shatwell, David G.
Dave, Ishan Rajendrakumar
Swetha, Sirnam
Shah, Mubarak
contents Timestamp prediction aims to determine when an image was captured using only visual information, supporting applications such as metadata correction, retrieval, and digital forensics. In outdoor scenarios, hourly estimates rely on cues like brightness, hue, and shadow positioning, while seasonal changes and weather inform date estimation. However, these visual cues significantly depend on geographic context, closely linking timestamp prediction to geo-localization. To address this interdependence, we introduce GT-Loc, a novel retrieval-based method that jointly predicts the capture time (hour and month) and geo-location (GPS coordinates) of an image. Our approach employs separate encoders for images, time, and location, aligning their embeddings within a shared high-dimensional feature space. Recognizing the cyclical nature of time, instead of conventional contrastive learning with hard positives and negatives, we propose a temporal metric-learning objective providing soft targets by modeling pairwise time differences over a cyclical toroidal surface. We present new benchmarks demonstrating that our joint optimization surpasses previous time prediction methods, even those using the ground-truth geo-location as an input during inference. Additionally, our approach achieves competitive results on standard geo-localization tasks, and the unified embedding space facilitates compositional and text-based image retrieval.
format Preprint
id arxiv_https___arxiv_org_abs_2507_10473
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle GT-Loc: Unifying When and Where in Images Through a Joint Embedding Space
Shatwell, David G.
Dave, Ishan Rajendrakumar
Swetha, Sirnam
Shah, Mubarak
Computer Vision and Pattern Recognition
Timestamp prediction aims to determine when an image was captured using only visual information, supporting applications such as metadata correction, retrieval, and digital forensics. In outdoor scenarios, hourly estimates rely on cues like brightness, hue, and shadow positioning, while seasonal changes and weather inform date estimation. However, these visual cues significantly depend on geographic context, closely linking timestamp prediction to geo-localization. To address this interdependence, we introduce GT-Loc, a novel retrieval-based method that jointly predicts the capture time (hour and month) and geo-location (GPS coordinates) of an image. Our approach employs separate encoders for images, time, and location, aligning their embeddings within a shared high-dimensional feature space. Recognizing the cyclical nature of time, instead of conventional contrastive learning with hard positives and negatives, we propose a temporal metric-learning objective providing soft targets by modeling pairwise time differences over a cyclical toroidal surface. We present new benchmarks demonstrating that our joint optimization surpasses previous time prediction methods, even those using the ground-truth geo-location as an input during inference. Additionally, our approach achieves competitive results on standard geo-localization tasks, and the unified embedding space facilitates compositional and text-based image retrieval.
title GT-Loc: Unifying When and Where in Images Through a Joint Embedding Space
topic Computer Vision and Pattern Recognition
url https://arxiv.org/abs/2507.10473