An implementation of a technology is described herein for deriving robust
non-local characteristics and quantizing such characteristics for blind
watermarking of a digital good. This technology finds the proper balance
between minimizing the probability of false alarms (i.e., detecting a
non-existent watermark) and the probability of misses (i.e., failing to
detect an existing watermark). The technology, described herein, performs
quantization index modulation (QIM) based upon non-local characteristics
of the digital good. Non-local characteristics may include statistics
(e.g., averages, median) of a group of individual parts (e.g., pixels) of
a digital good. This abstract itself is not intended to limit the scope
of this patent. The scope of the present invention is pointed out in the
appending claims.
