Scalable attribute-driven image retrieval and re-ranking

An apparatus for retrieval of images from a large-scale database of images, comprising:

• an interface to a large-scale database of multiple images;
• memory for storing computer-executable process steps;
• and
• one or more processors for executing the computer-executable process steps stored in the memory;
• wherein the computer-executable process steps include steps to:
• obtain a user designation of a query image;
• extract features representative of the query image;
• search the large-scale database of images to obtain a candidate set of images from the large-scale database of images based at least in part on similarity of the features for the query image to features of the images in the large-scale database of images;
• rank the obtained candidate images;
• project the query image into a subspace that captures semantic attributes;
• and
• re-rank the ranked candidate images based at least in part on similarity of a result of projecting the query image into the subspace that captures semantic attributes to a result of projecting the images in the large-scale database of images into the subspace that captures semantic attributes, wherein the similarity of the result of projecting the query image into the subspace that captures semantic attributes to the result of projecting the images in the large-scale database of images into the subspace that captures semantic attributes is measured by a distance metric that measures distances between attributes.