Embedding spatial information into image content description for scene retrieval

This article presents Δ-TSRΔ-TSR, an image content representation describing the spatial layout with triangular relationships of visual entities, which can be symbolic objects or low-level visual features. A semi-local implementation of Δ-TSRΔ-TSR is also proposed, making the description robust to viewpoint changes. We evaluate Δ-TSRΔ-TSR for image retrieval under the query-by-example paradigm, on contents represented with interest points in a bag-of-features model: it improves state-of-the-art techniques, in terms of retrieval quality as well as of execution time, and is scalable. Finally, its effectiveness is evaluated on a topical scenario dedicated to scene retrieval in datasets of city landmarks.