9. A non-transitory computer-readable medium storing software having stored thereon instructions, which, when executed by one or more computers, cause the one or more computers to perform operations of: obtaining a query image that has been submitted by a user of an image search system; determining that the query image is indicated to be associated with an object; obtaining, for the query image: (i) one or more training images of a corpus of training images that are indicated to be associated with the object, and (ii) for each one of the one or more training images that are indicated to be associated with the object, a similarity score that reflects a level of similarity between the query image and the respective training image; determining to add the query image to the corpus of training images that are indicated to be associated with the object in response to the similarity score that reflects the level of similarity between the query image and the respective training image satisfying a threshold; and training the image search system to recognize the object in subsequently received query images, using the corpus of training images that are indicated to be associated with the object.
13. The non-transitory computer-readable medium of claim 9 , further comprising: obtaining one or more other query images; determining that the query image and the one or more other query images matches a particular object; and in response to determining that the query image and the one or more other query images matches the particular object, adding the query image and the one or more other query images to a corpus of training images associated with the particular object.