Minimal code example for that CTF task that drove you insane
- Use Google lens or tineye to find the original unmodified image 2: Use this code
orig=Im.open('secret-sloth.png')
sloth = np.asarray(sloth)[:,:,:3].astype(int)
orig=Im.open('iHCQX6p.png') # original sloth image found on reddit
orig = np.asarray(orig).astype(int)
# compute FFT for the original sloth image, and the one with the secret message
origfft=np.fft.fft2(orig)
slothfft=np.fft.fft2(sloth)
# Now the magic! We subtract the spectra of the original sloth from the secret sloth,
# leaving behind just the spectral components that contain the message
out = abs(np.fft.fft2(slothfft-origfft))
out = abs(slothfft-origfft)
# normalize
out=(out+out.min())
out/=out.max()
ax.imshow(10*out)
