Moire Images

This is the spatial equivalent of FM radio.

We take an image, and use it to modulate a high frequency carrier wave, then print that out on paper—we call this the Frequency Modulation (FM) image. You can see there’s something going on, but my face is not visible because the information is hidden in the frequency of the waveform.

Original Image

FM Image (print this on paper)

Carrier Image (print this on transparency)

What you see with one on top of the other

Next, we print out just the carrier frequency on a transparency, and when it is placed on top of the FM image, it demodulates the modulation that produced the FM image, making my face visible again!

This is the spatial equivalent of what your radio receiver does when you listen to FM radio.

If you don’t like my face, shoot me an email with an image you’d like to frequency modulate, and I’ll make you one of your very own :) 

lwaller (at) alum.mit.edu