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

• US 20080022114A1
• Filed: 09/07/2007
• Published: 01/24/2008
• Est. Priority Date: 07/02/1996
• Status: Active Grant

• Current Assignee: Wistaria Trading Inc.
• Original Assignee: Wistaria Trading Inc.
• Inventors: Moskowitz, Scott
• Granted Patent: US 7,822,197 B2
• Time in Patent Office: Days
• US Class Current: 713/176
• CPC Class Codes: G06T 1/0028 Adaptive watermarking, e.g. Human Visual System [HVS]-based watermarking
• CPC Class Codes: G06T 2201/0064 for copy protection or copy management, e.g. CGMS, copy only once, one-time copy

Abstract

Disclosed herein are methods and systems for encoding digital watermarks into content signals. Also disclosed are systems and methods for detecting and/or verifying digital watermarks in content signals. According to one embodiment, a system for encoding of digital watermark information includes: a window identifier for identifying a sample window in the signal; an interval calculator for determining a quantization interval of the sample window; and a sampler for normalizing the sample window to provide normalized samples. According to another embodiment, a system for pre-analyzing a digital signal for encoding at least one digital watermark using a digital filter is disclosed. According to another embodiment, a method for pre-analyzing a digital signal for encoding digital watermarks comprises: (1) providing a digital signal; (2) providing a digital filter to be applied to the digital signal; and (3) identifying an area of the digital signal that will be affected by the digital filter based on at least one measurable difference between the digital signal and a counterpart of the digital signal selected from the group consisting of the digital signal as transmitted, the digital signal as stored in a medium, and the digital signal as played backed. According to another embodiment, a method for encoding a watermark in a content signal includes the steps of (1) splitting a watermark bit stream; and (2) encoding at least half of the watermark bit stream in the content signal using inverted instances of the watermark bit stream. Other methods and systems for encoding/decoding digital watermarks are also disclosed.

Claims

1-16. -16. (canceled)

17. A system for encoding a watermark in a digital signal, comprising:

a generator for generating a plurality of watermark pseudo-random key bits; and

an encoder for encoding the watermark in the digital signal using the watermark pseudo-random key bits and characteristics of the digital signal.

18. The system of claim 17, wherein the generator is selected from the group consisting of a non-linear generator and a chaotic generator.

19. The system of claim 17, wherein the characteristics of the digital signal comprise mathematically defined functions of the digital signal.

20. A system for encoding a watermark in a digital signal, comprising:

a mapper for mapping pseudo-random key and processing state information to effect an encode/decode map using a generator; and

an encoder for encoding the watermark in the digital signal using the encode/decode map and characteristics of the digital signal.

21. The system of claim 20, wherein the generator is selected from the group consisting of a non-linear generator and a chaotic generator.

22. The system of claim 20, wherein the characteristics of the digital signal comprise mathematically defined functions of the digital signal.

23-88. -88. (canceled)

89. A process for embedding a watermark in a signal, comprising:

generating watermark key bits; and

embedding the watermark using the generated watermark key bits into features of the signal.

90. The process of claim 89, wherein the signal features are selected from at least one of the group comprising portions of the signal or signal characteristics.

91. The process of claim 89, further comprising using the watermark key bits to detect the watermark.

92. The process of claim 89, further comprising using the watermark key bits to generate a plurality of keys.

93. The process of claim 89, further comprising using the watermark key bits to embed a plurality of watermarks.

94. The process of claim 93, wherein the plurality of watermarks are associated with a plurality of keys.

95. The process of claim 89, wherein embedding and/or detection vary according to the watermark key bits.

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

mapping key and processing state information to affect a watermark map of a signal; and

encoding a watermark into the signal according to the watermark map.

97. The article of manufacture of claim 96, wherein the watermark map is sparse.

98. The article of manufacture of claim 96, wherein the watermark map is associated with an envelope.

99. The article of manufacture of claim 96, wherein the watermark is encoded in a portion of the watermark map.

100. The article of manufacture of claim 96, wherein the watermark is decoded according to the watermark map.

101. The article of manufacture of claim 96, wherein the watermark map is determined using a perceptual model.

102. The article of manufacture of claim 96, wherein the encoding introduces dither.

103. A system for encoding a watermark in a digital signal, comprising:

a generator for generating a plurality of key bits;

an identifier for identifying candidate bits in the digital signal; and

an encoder for encoding the watermark in the identified candidate bits using key bits.

104. The system of claim 103, wherein the candidate bits comprise noise-like characteristics.

105. The system of claim 103, wherein the key bits correspond to a random or pseudo random key.

106. The system of claim 103, wherein the candidate bits are masked.

107. The system of claim 103, wherein the watermark is encoded in non-subtractive dither.