1. A method of using spectral components of one or more spatial cross sections of pixels of an image for recognizing a similar image, the method comprising: generating a first hologram of spectral characteristics of one or more spatial cross-sections of pixels of a first image; generating a second hologram of spectral characteristics of one or more spatial cross-sections of pixels of a second image; comparing the first hologram to the second hologram by: a) scanning the one or more spatial cross-sections of pixels of the first image to create first complex waveforms; and, b) using the first complex waveform to modulate a reference beam to interrogate the second hologram.