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

An article of manufacture comprising a machine readable medium, having thereon stored instructions adapted to be executed by a processor, which instructions when executed result in a process comprising:

• pre-analyzing a digital signal to identify potential watermarking locations within the digital signal, which potential watermarking locations are suitable for embedding one or more bits of a watermark message;
• pre-processing a watermark message to determine an exact length of the watermark message to be embedded within the digital signal based on the pre-analyzing step;
• determining the size of a watermarking key to embed the exact length of the watermark message as determined by the pre-processing step, into the digital signal as determined by the pre-analyzing step;
• and
• using the watermarking key to embed the watermark message into the digital signal at the locations identified by the pre-analyzing step.

An method of encoding a watermark message into a digital signal, comprising:

• pre-analyzing a digital signal to identify potential watermarking locations within the digital signal, which potential watermarking locations are suitable for embedding one or more bits of a watermark message;
• pre-processing a watermark message to determine an exact length of the watermark message to be embedded within the digital signal based on the pre-analyzing step;
• and
• embedding the exact length of the watermark message into the digital signal using the locations identified by the pre-analyzing step.

An article of manufacture comprising a machine readable medium, having thereon stored instructions adapted to be executed by a processor, which instructions when executed result in a process comprising:

• selecting a sample window in a digital signal having embedded watermarks;
• determining a quantization interval of the sample window, wherein the quantization interval can be used to quantize normalized sample windows;
• normalizing the sample window to provide normalized samples, wherein the normalized samples conform to a limited range of normalized values that can be divided by the quantization interval into distinct quantization levels;
• identifying potential watermark locations within the sample window using a psychoacoustics and/or psycho-visual model, which potential watermark locations are capable of carrying one or more bits of a watermark message;
• and
• analyzing quantization level of the normalized samples to determine a portion of the watermark message.

A process for decoding a watermark message from a digital signal, comprising:

• selecting a sample window in a digital signal having embedded watermarks;
• determining a quantization interval of the sample window, wherein the quantization interval can be used to quantize normalized sample windows;
• normalizing the sample window to provide normalized samples, wherein the normalized samples conform to a limited range of normalized values that can be divided by the quantization interval into distinct quantization levels;
• identifying potential watermark locations within the sample window using a psychoacoustics and/or psycho-visual model, which potential watermark locations are capable of carrying one or more bits of a watermark message;
• and
• analyzing quantization level of the normalized samples to determine a portion of the watermark message.

A method of analyzing a potentially watermarked, digital signal for watermarks comprising steps of:

• obtaining a potentially watermarked digital signal;
• obtaining an unwatermarked sample signal, said sample signal being different in length than the potentially watermarked digital signal;
• time aligning the unwatermarked sample signal to the potentially watermarked digital signal to identify a segment of the potentially watermarked digital signal that corresponds to the unwatermarked sample signal;
• gain adjusting the unwatermarked sample signal to the corresponding segment of the potentially watermarked digital signal;
• estimating a watermarked sample by substracting the gain-adjusted unwatermarked sample from the corresponding segment of the potentially watermarked digital signal;
• and
• scanning the estimated watermarked sample signal for one or more portions of a watermark message.

A system for encoding of a digital watermark into a signal, comprising:

• a window selector for selecting a sample window in the signal;
• an interval calculator for determining a quantization interval of a selected sample window, where the quantization interval may be used to quantize normalized window samples;
• a sampler for normalizing the sample window to provide normalized samples, where the normalized samples conform to a limited range of normalized values that are proportional to un-normalized samples, and where the normalized values can be divided by the quantization interval into distinct quantization levels;
• a processor for identifying a plurality of optimal locations in the signal for embedding a digital watermark;
• and
• an encoder for randomly encoding one or more portions of a digital watermark into the plurality of identified optimal locations in the signal.