Visual Cryptography

I read an interesting article the other day. I’ll skip to the end to show you the result. Check out this pair of binary images:

img1

img2

Not too fascinating, huh? If you print both images out on transparency though, and stack them together, you’ll get this…

both

Hopefully that worked (with my limited CSS skills, I don’t think I got it exactly right). I couldn’t get the CSS exactly right, so the above image is really just the pairwise minimum of both images above. But how I accomplish this miracle? My own simple python implementation of the ideas cribbed from this page. Script to come later.

3 thoughts on “Visual Cryptography”

  1. looks a lot like some of our early attempts at raytracing (circa late 1980’s) – dithering to a laser printer.

  2. superimposing the images in CSS would be as simple as style=”background: url(img2.png)” 😉

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