Make Your Own Secret Messages From Space!

Introduction: Make Your Own Secret Messages From Space!

About: Every now and then I come up with a unique idea. And then I find someone else has already thought of it . . . which is AWESOME! Who knew there were so many kindred spirits on the web! YOU GO all o' us!

During my [https://www.instructables.com/id/Decoding-Secret-Messages-from-Space/ playful expermints] with Fourier Transforms, I discovered that you can overlay an image on top of a Fourier transformed image, and freely convert back and forth from Fourier to regular space. Each transform would descramble the previously FFT'd image. So in short, you can hide the FFT of one image in another image.

If you appreciate this instructable, please visit my blog for more of my crazy ideas: [http://GoodCleanCrazy.wordpress.com GoodCleanCrazy.wordpress.com]

Here's the plainly plain message that I want to hide:

Step 1: FFT Your Image!

GIMP has an FFT plugin filter (so I'm told), but I used a plugin for Shake.

I've put it in the bottom half of the picture so it will still be intelligible after being transformed. Here's the FFT of my secret message:

Step 2: Hide Your FFT in Another Image

My first test overlaid the FFT over a color wheel, and it's a bit obvious something wierd is in the center:

Step 3: Offset or Scroll the FFT

If we scroll the FFT over to the corners and scale down the brightness, it's much harder to spot when overlaid with the zucchini-in-a-bottle image:

Step 4: FFT the Image to Decode

FFT the image again to see the secret message again. Some information is lost when the image is saved in the .tif format, but after we scale the brightness back up, we get this:

Step 5: My Whole Process in an Image

Here's my whole shake tree for both the test image and the final masterfully masterfool zucchini-hiding-a-secret image. Have fun with this!

Digital Days Photo Contest

Participated in the
Digital Days Photo Contest

Be the First to Share

    Recommendations

    • Plastic Contest

      Plastic Contest
    • The 1000th Contest

      The 1000th Contest
    • Battery Powered Contest

      Battery Powered Contest

    5 Discussions

    0
    AndyGadget
    AndyGadget

    11 years ago on Introduction

    Clever - I wonder how much this method is being used for covert transmission of messages already.  It's many years since I had anything to do with Fourier transforms.  I passed the exams, but more by remembering the equations and plugging in the numbers than actually unsderstanding them.
    I can see how you can convert an audio signal to the time domain, but how does that relate when you're transforming an image?

    0
    AndyGadget
    AndyGadget

    Reply 11 years ago on Introduction

    I get the idea. The link makes interesting reading - Thanks.

    0
    royalestel
    royalestel

    Reply 11 years ago on Introduction

    Thanks!  It's good to be back.  I liek making stuff and seeingthe great things others have created.