Then you create a hologram of the image. Creating the hologram involves optically splitting a laser beam, then using mirrors to direct the split beams. One beam, called the object beam, illuminates the page before it joins with another beam, called the reference beam, to create an interference pattern that's recorded as a hologram. To read the data, you simply recreate the reference beam and shine it on the hologram to reproduce the image of the page. It's no trick at all to read the image with a CCD array, which is simply an array of photodetectors.
Holographic storage has all sorts of advantages.
To begin with, holograms aren't stored as pictures but as wave-interference patterns. For storage, that means a defect in the storage medium won't wipe out any data. The information is stored redundantly throughout the hologram. You also can store multiple holograms in the same place, or volume, by varying the laser's angle or wavelength. And since holographic storage will read a full page at a time, performance also promises to be impressive.