Smage is a program with which any kind of data can be embedded into an image using digital watermarking techniques. The data is encoded by slightly altering the image's colors, which is invisible to the naked eye. The data is directly encoded into those regions that have been selected and that can be of any shape.
The two images show examples that have been generated using this technique. As it can be seen it is possible to encode simple texts or speech bubbles as well as dictionary entries and other images. Other coded images that were generated using Smage can be found in the gallery.
The embedded information appears once the mouse cursor enters a region that has additional data encoded. As soon as the cursor leaves the region the embedded information disappears again.
The program Smage was developed within the scope of a project aided by the DFG (German Research Foundation) at the Department of Simulation and Graphics (University of Magdeburg) by Lothar Schlesier and Henry Sonnet.