Current steganographic techniques introduce permanent changes to images when information is stuffed into them. A new watermarking technique developed by researchers at the U. of Rochester restores the original image 100% when extracting the encrypted data.
This new technology, ostensibly for certifying authenticity and accuracy of images for law enforcement and copyright protection can also be applied to data hiding. ARG developers should soon have a new tool allowing more diverse puzzles centered around image manipulation.
For example, two images might be merged in such a way that renders both images unviewable. Given the right software and key, both images would be revealed. Because the technology is lossless and reversible, no quality is lost in the original images.
The article on C|Net can be found here.