1. A method comprising: selecting an area in an image; accessing a length of at least one encoded wavelength for the area; identifying one or more candidate wavelengths in the area in at least one direction that include at least one peak; and comparing the length of the at least one encoded wavelength to the length of at least one of the one or more candidate wavelengths to calculate an alteration ratio, the alteration ratio identifying at least one of a scale, a rotation, or an offset of the image; wherein the at least one encoded wavelength includes a plurality of encoded wavelengths, the one or more candidate wavelengths include a plurality of candidate wavelengths and the identifying comprises: accessing a defined ratio for the plurality of encoded wavelengths; and identifying the plurality of candidate wavelengths in the defined ratio in the area in the at least one direction that include the at least one peak in a Discrete Fourier Transform (DFT) of pixel variable values for the region.