Digital watermarking, also referred to as simply watermarking, is a pattern of bits inserted into a digital image,
audio or video file that identifies the file's copyright information (author, rights, etc.). The name comes from the
faintly visible watermarks imprinted on stationery that identify the manufacturer of the stationery. The purpose of
digital watermarks is to provide copyright protection for intellectual property that's in digital format.
Unlike printed watermarks, which are intended to be somewhat visible, digital watermarks are designed to be
completely invisible, or in the case of audio clips, inaudible. Moreover, the actual bits representing the
watermark must be scattered throughout the file in such a way that they cannot be identified and manipulated.
And finally, the digital watermark must be robust enough so that it can withstand normal changes to the file,
such as reductions from lossy compression algorithms.
Watermarking is also called data embedding and information hiding.
Dr. Andrew Tirkel is the person identified worldwide as the first to coin the term “digital watermarking”. His
paper titled “Electronic Water Mark” (1992) has been the backbone of the first digital watermarking patent as well
as numerous posterior patents. If you make a search in google, you will find numerous hits that identify him as
one of the masterminds behind the creation of the digital watermark.
Below is a fragment from a letter written by Dr. Tirkel, describing our joint initiative:
“The current collaboration between Dr. Moreno and Dr. Tirkel arose due to a common interest in sequences.
Recently, Dr. Moreno instigated joint research into arrays by visiting our group in Australia, and presenting a
brilliant idea on how to generalize our construction of families of arrays with good correlation. Personally, this
persuaded me to postpone my retirement from this area. Even 4 months ago, I never could have imagined such a
collaboration!!! In that short period, we have studied the generalized construction in two dimensions, and Dr. Moreno
has come up with an even newer construction, which lifts the construction into three dimensions and more.
Such arrays are highly useful in the field of digital watermarking, and digital fingerprinting of multi-dimensional
data, such as audio and video, and in other information security applications. We have filed a provisional patent
application for watermarks built using our construction, and intend
to publish the work at international conferences and in journals. The new construction is incredibly rich, and it
is expected that the research work will continue for a while. With this in mind, we are planning to apply for
research funding and establish a schedule of regular visits between Puerto Rico and Australia.”