Vocabulary tree incremental indexing for scalable location recognition

This work aims at developing a scalable vision-based location recognition system where the backend database can be updated incrementally. Our proposed framework enables incremental indexing of vocabulary tree model, which efficiently includes new data into model refinement without re-generating entire model from overall dataset. An adaption trigger criterion is presented to lessen system computational cost, which is achieved by density-based relative entropy estimation between original dataset and newly coming data. Experiments on Seattle urban scene datasets with over 20 K street-side images show the effectiveness of our work.