Exploring temporal proximity and spatial distribution of terms in web-based search of event-related images

Abstract

Pictures in media sharing applications are increasingly accompanied with geotags. For this reason, we stress the importance of exploring the possibility of applying spatial, as well as the temporal dimensions in searching event-related pictures. Specifically, we propose extended query expansion models that exploit the information about the temporal neighbourhoods among pictures in a collection and leverage on the spatio-temporal distribution of the candidate expansion terms to re-weight and expand the initial query. To evaluate our approach, we conduct extensive experiments on a large dataset consisting of 88 million pictures from Flickr. The results from these experiments demonstrate the viability and effectiveness of our method with respect to retrieval performance, considering both a large dataset and query pictures with restricted size of terms.