Figure 1
L. Saunoriene & M. Ragulskis, Phys. Rev. E (2011)

Hiding in plain sight. To hide the picture, a dot-skeleton version (top) is embedded in a noisy grayscale image and then allowed to diffuse into self-organizing patterns according to the equations of a predator-prey model. The image that results (middle) can only be decoded by rerunning the algorithm with the original noisy image and taking the difference (bottom).