1. An apparatus, comprising: a reference comparator to: compare a first reference region of a first reference image stored in a database with a first region of a first image to determine a first match value, the first region corresponding spatially to the first reference region; in response to determining the first match value satisfies a first threshold, compare a second reference region of the first reference image with a second region of the first image to determine a second match value, the second region corresponding spatially to the second reference region; and in response to determining the second match value satisfies a second threshold, associate the first image with a product associated with the first reference image, the product being associated with a plurality of second reference images stored in the database; and a reference image manager to, in response to determining the second match value satisfies the second threshold: decrement second index values associated with ones of the second reference images; and remove a reference record associated with one of the second reference images from the database based on a corresponding one of the second index values satisfying a first condition, the removal of the reference record reducing a storage space required to store reference records in the database, at least one of the reference comparator or the reference image manager including hardware.