Optimization methods for the insertion, protection, and detection of digital watermarks in digitized data

A method of encoding and decoding watermarks in a signal, comprising insertion and detection of abstract signal features in said signal to carry watermark information, wherein said abstract signal features are mathematical functions of the input sample window, and by extension, adjacent sample windows.

A method of pre-analyzing a digital signal for encoding digital watermarks using a digital filter comprising determining what changes in the digital signal will be affected by the digital filter.

A method of error coding watermark message certificates using cross interleaved codes which use error codes of high redundancy, including codes with Hamming distances of greater than or equal to n, wherein n is a number of bits in a message block.

A method of pre-processing a watermark message certificate comprising determining an exact length of the watermark message as it will be encoded.

A method of encoding a watermark in a digital signal, comprising the steps of:

• generating watermark pseudo-random key bits using a non-linear generator;
• and
• encoding the watermark in the digital signal using the watermark pseudo-random key bits and characteristics of the digital signal.

A method of encoding a watermark in a digital signal, comprising the steps of:

• generating watermark pseudo-random key bits using a chaotic generator;
• and
• encoding the watermark in the digital signal using the watermark pseudo-random key bits and characteristics of the digital signal.

A method of encoding a watermark in a digital signal, comprising the steps of:

• mapping pseudo-random key and processing state information to effect an encode/decode map using a non-linear generator;
• and
• encoding the watermark in the digital signal using the encode/decode map and characteristics of the digital signal.

A method of encoding a watermark in a digital signal, comprising the steps of:

• mapping pseudo-random key and processing state information to effect an encode/decode map using a chaotic generator;
• and
• encoding the watermark in the digital signal using the encode/decode map and characteristics of the digital signal.

A method of guaranteeing watermark certificate uniqueness comprising attaching a timestamp or user identification dependent hash or message digest of watermark certificate data to the certificate.

A method of generating and modulating a local noise signal to contain watermark information, wherein the noise signal is a function of at least one variable which depends on key and processing state information.

A method of varying watermark quantizations such that the dither changes an absolute quantization value, but does not change a quantization level or information carried in the quantization.

A method of encoding watermarks comprising steps of:

• inverting at least one instance of the watermark bit stream;
• and p1 encoding at least one instance of the watermark using said inverted instance of the watermark bit stream.

A method of decoding watermarks comprising steps of:

• considering an original watermark synchronization marker, an inverted watermark synchronization marker, and inverted watermarks;
• and
• decoding based on the considering step.

A method of encoding and decoding watermarks in a signal using a spread spectrum technique to encode or decode where information is encoded or decoded at audible levels and the encoding and decoding methods are pseudo-random over frequency.

A method of encoding and decoding watermarks in a signal using a spread spectrum technique to encode or decode where information is encoded or decoded at audible levels and the encoding and decoding methods are pseudo-random over time.