1. A method for processing an image by a sender, the method comprising: sending a first query of the image to a receiver, wherein the first query comprises a first number of feature points which is a subset of a first set of feature points of the image invariant to rotation and scaling in creating the image; receiving feedback from the receiver, wherein the feedback is generated by the receiver based on searching an image repository using information from the first query; deciding whether there is a match of the image in the image repository based on the received feedback; sending by the sender a second query of the image to the receiver when the sender decides there is no match of the image in the image repository based on the first query, wherein the second query comprises a second number of feature points which is a subset of the first set of feature points of the image invariant to rotation and scaling in creating the image, and wherein the first query and second query are disjoint without any common feature point; and deciding there is a match of the image in the image repository when a ratio of a second number with the first number is larger than a threshold, where there are the second number of matched feature points from the image repository among the first number of feature points of the first query, and the threshold is generated based on information about the image repository.