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; and deciding whether there is a match of the image in the image repository based on the received feedback.