A form of error processing is used to decode steganographic messages
embedded in image and audio signals in the presence of distortion, which
tends to introduce errors in steganographic data communication. Content
signals with auxiliary embedded data are analyzed to detect embedded
message signals. Confidence values are assigned to the message signals
and used to ascertain whether a message has been accurately detected.
Error processing enables accurate message extraction in the presence of
"soft errors" in the embedded message signal. This error processing
enables more effective recovery of the steganographic message from
content signals that undergo distortion and/or loss transformations after
being embedded with steganographic data.