A unified inverted index for an efficient image and text retrieval

We present an efficient method for approximate search in a combination of several metric spaces - which are a generalization of low level image features - using an inverted index. Our approximation gives very high recall with subsecond response time on a real data set of one million images extracted from Flickr. We further exploit the inverted index to improve efficiency of the query processing by combining our search in metric features with search in associated textual metadata.