PyEvcs
Extended Visual Cryptography Schemes in Python
...If the two participants come together, they'll be able to reveal the secret image without a computer, perfectly superimposing the transparencies they own. Analyzing a single share, no one will be able to obtain any information considering the secret image no matter the computing or the analyzing power. In an Extended Visual Cryptography Scheme, both the secret image and the shares are meaningful images like a landscape, a building or a beautiful girl, hiding the very intention to conceal a secret. PyEvcs is a command line Python application allowing you to experiment with Extended Visual Cryptography Schemes for "natural" continuous tone images.