Deep Learning-Based Image Geolocation for Travel Recommendation via Multi-Task Learning

Localizing images by visual information is a very challenging task in image-based travel recommendations. Travelers take a large number of pictures every day and share them on social networks (Facebook, Sina Weibo, Yelp, etc.). Many of these images are associated with the location where they are taken. But for images that do not associate with geographic location information, how to estimate where they are taken? With the rapid development of social media, the increasing number of shared geographic-labeled images brings an opportunity to address this problem. Using geographic-labeled images to estimate the location of unlabeled images is a popular approach. In this paper, we propose an image geographic location estimation model via multi-task learning (GLML). It combines the classification task and retrieval task to calculate the similarity between the query image and dataset images. Additionally, it fuses multi-global features through multiple global pooling techniques to enhance feature extraction. Each part of the proposed GLML model is flexible and extensible. Experiments on seven public datasets show the effectiveness of the proposed model.