1. A method for classifying or comparing data objects comprising: detecting, using a computer, a first set of points of interest in a first data object and a second set of points of interest in a second data object; computing feature descriptors for each data object from said points of interest; forming a multi-resolution histogram from the feature descriptors of each data object; and computing a weighted intersection from the multi-resolution histogram for the first data object as compared with the multi-resolution histogram for the second data object.