Ranking over hashes

摘要

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for training an image ranking model to rank images based on hashes of their contents using a lookup table. An image training set is received. An image ranking model is trained with the training set by generating an image hash for each image of the ordered pair of images based on one or more features extracted from the image, computing a first score for a first image hash of a first image of the pair and a second score for a second image hash of a second image of the pair using the image ranking model, determining whether to update the image ranking model based on the first score and the second score, and updating the image ranking model using an update value based on the first score and the second score.

主权项

1. A computer-implemented method comprising:
receiving a search query; identifying a lookup table corresponding to the search query; for each image in a collection of images:
generating an image hash for the image based on one or more features extracted from the image, wherein the image hash comprises a plurality of hash characters, andcomputing a score for the image hash using the lookup table, wherein computing the score for each image hash comprises summing lookup table weights for each hash character of the plurality of hash characters, and wherein the lookup table includes a first index that corresponds to the lookup table value of each hash character, and a second index that corresponds to a position of each hash character in the image hash; ordering the images by the score of each image hash; and providing a group of the ordered images as search results responsive to the search query.