Key points are not available for this paper at this time.
Late fusion of independent retrieval methods is the simpler approach and a widely used one for combining visual and textual information for the search process. Usually each retrieval method is based on a single modality, or even, when several methods are considered per modality, all of them use the same information for indexing/querying. The latter reduces the diversity and complementariness of documents considered for the fusion, as a consequence the performance of the fusion approach is poor.
Escalante et al. (Thu,) studied this question.