The needs of efficient image query is rapidly increasing under the development of broadband network and multimedia communication. The recent techniques in the image query extract thousands of points of interest (POI) from each image, and represent the feature of each POI by a Scale Invariant Feature Transform (SIFT) vector. The similarity among images is evaluated by the matching of SIFT vectors and used for the query. Crucial issues in the similarity evaluation are an appropriate formulation of the distance measure to evaluate the similarity between images and the establishment of an efficient computation method of the distance measure. In this report, we formulate the distance measure based on extreme value analysis and propose an efficent computaion method of the distance measure based on a k-NN query technique named "SASH".