Patent ID: 6910030

Claim:
A method for adaptively searching a feature vector space, the method comprising the steps of: (a) performing a similarity measurement on a given query vector within the feature vector space; and (b) applying search conditions limited by the result of the similarity measurement obtained in the step (a) and performing a changed similarity measurement on the given query vector, wherein the step (b) further comprises the sub-steps of: (b-1) obtaining candidate approximation regions by performing approximation level filtering according to a distance measurement limited by the result of the similar measurement obtained in the step (a); and (b-2) performing data level filtering on obtained candidate approximation regions and wherein step (a) comprises the sub-steps of: (a-1) obtaining a predetermined number of nearest candidate approximation regions by measuring the distance between the query vector and each approximation region; and (a-2) obtaining K nearest neighbor feature vectors by measuring the distances between all feature vectors in the obtained candidate approximation regions and the query vector, where K is a positive integer.