Systems and methods for descriptor vector computation are described herein. An embodiment includes (a) identifying a plurality of regions in the digital image; (b) normalizing the regions using at least a similarity or affine transform such that the normalized regions have the same orientation and size as a pre-determined reference region; (c) generating one or more wavelets using dimensions of the reference region; (d) generating one or more dot products between each of the one or more wavelets, respectively, and the normalized regions; (e) concatenating amplitudes of the one or more dot products to generate a descriptor vector; and (f) outputting a signal corresponding to the descriptor vector.