Abstract: The present invention generally relates to processing audio, video and images. One claim recites a method including: obtaining media signal comprising a steganographic signal hidden therein; utilizing a programmed electronic processor, selecting portions of the media signal for steganographic signal detection, wherein the subset of the media signal is selected based on at least one or more predetermined probability factors, in which a probability factor comprises a selection criteria or rule to identify portions of the media signal which have a higher likelihood of including a steganographic signal relative to other portions of the media signal; and utilizing a programmed electronic processor, analyzing selected portions of the media signal to obtain the steganographic signal. Of course, other claims and combinations are provided as well.

Abstract: Machine readable signals embedded in other media signals include a circular structure in a transform domain to facilitate detection. The machine readable signals are not apparent to human observers of rendered media containing the machine readable signals, such as images and documents. A detector captures the media signal, transforms it to the transform domain, and then uses the circular structure in the transform domain to facilitate detection despite rotation of the media signal.

Abstract: This disclosure describes methods and systems for encoding and decoding signals from a host signal such as audio, video or imagery. One claim recites a method comprising: receiving a host signal carrying an auxiliary signal; extracting data representing at least some features of the host signal, said extracting utilizes one or more processors; using the data representing at least some features of the host signal to determine a key; and detecting the auxiliary signal in a transform domain associated with the key, the detecting utilizes one or more processors. Other claims and combinations are provided as well.

Abstract: The present invention generally relates to digital watermarking and steganography. In one implementation, a method is provided including acts of receiving a media signal comprising a steganographic signal redundantly embedded therein; selecting a subset of the media signal for steganographic signal detection, wherein the subset of the media signal is selected based on at least one media signal characteristic associated with the subset; and detecting a steganographic signal hidden in the subset of the media signal. In another implementation, a digital watermark detector is providing including: electronic processing circuitry; memory; and executable instructions stored in memory for execution by said electronic processing circuitry.

Abstract: This disclosure describes novel methods for generating unique copies of content. One method combines the functions of the master copy and unique copy watermarks. In particular, the method generates a unique copy by varying the manner in which the master copy watermark is embedded in unique copies of a content item. In one embodiment, the master copy watermark is repeated within the content item and its location is varied in a unique pattern that comprises the unique copy watermark. The unique copy is generated by producing a copy in which master copy watermarks are embedded in a unique pattern. For instance in one embodiment, the locations of the master copy watermarks in the content item are represented as a vector of delta values in which each delta value corresponds to the distance between a corresponding instance of the master copy watermark, and a neighboring instance of the master copy watermark.

Abstract: The present invention relates to toys and game applications that are enhanced with digital watermarks. In one embodiment, a character card includes a unique identifier in the form of a digital watermark. The identifier is used to link to a database record, which can be updated to reflect changes in game attributes. Some such game attributes include life, character type and name, health, strength, and power levels. The data record can be updated or modified to reflect changes in attributes due to activity or events during a computer software game. The database record can be used by the computer software game to alter or enhance the game. In another embodiment, a toy interacts with toy components or cards via digital watermarks. Digital watermarks enhance games, toys and books in still other embodiments.

Abstract: A variety of systems responsive to watermarked documents are detailed. In one, watermarking is employed to facilitate system access. In another, security is provided through analyzing digitally watermarked documents. In yet another, a digital watermark-based combination lock is adapted to analyze a sequence (and perhaps an orientation) of presented digitally watermarked cards.

Abstract: Variable message coding protocols enable greater flexibility in encoding auxiliary data in media signals. One such protocol employs a version identifier that indicates the type of coding used to process an auxiliary data message before it is embedded in a host media signal. This version identifier specifies the type of error robustness coding applied to a variable message. The error robustness coding may be varied to alter the message payload capacity for different versions of auxiliary data embedding and reading systems. Another protocol uses control symbols to specify the format and variable length of the variable message.

Abstract: This disclosure describes methods and systems for encoding a digital watermark into and/or detecting a digital watermark from a host (or media) signal such as audio, video or imagery. One implementation involves a method of detecting a digital watermark. The method includes: receiving a host signal carrying a digital watermark; computing attributes of the host signal; using the attributes of the host signal to compute a key; and using the key to detect the digital watermark in a transform domain dependent on the key. Other methods, systems and apparatus are provided as well.

Abstract: A wavelet domain watermark encoder and decoder embed and detect auxiliary signals in a media signal, such as a still image, video or audio signal. The watermark encoders and decoders employ techniques that take advantage of processing plural levels of resolution of the signal to embed and detect auxiliary information in the media signal.

Abstract: Certain forms of distortion make it difficult to recover hidden data embedded in an audio or image signal by quanitzation techniques. To compensate for this distortion, an embedded data reader analyzes a statistical distribution (e.g., a histogram) of feature samples (124) in an audio or image signal suspected of having hidden auxiliary data to derive an estimate of quantizers used to encode a reference signal (126). The estimated quantizers then recover the reference signal (126), and the reader uses the reference signal (126) to determine and compensate for geometric or temporal distortion, like spatial scaling and rotation of image data, and time scale and speed changes of audio data. After compensating for such distortion, the reader can then more accurately recover hidden message data using quantization techniques to extract the message. The reference signal (126) is preferably repeated in blocks of the image or audio data to enable synchronization at many points in an image or audio data stream.

Abstract: Variable message coding protocols enable greater flexibility in encoding auxiliary data in media signals. One such protocol employs a version identifier that indicates the type of coding used to process an auxiliary data message before it is embedded in a host media signal. This version identifier specifies the type of error robustness coding applied to a variable message. The error robustness coding may be varied to alter the message payload capacity for different versions of auxiliary data embedding and reading systems. Another protocol uses control symbols to specify the format and variable length of the variable message.

Abstract: A curve fitting method is used to synchronize a reader of embedded data in a media signal. A circular reference signal is embedded in the media signal. After geometric distortion of the media signal, the reference signal is distorted, yet still detectable. The amount of distortion is derived by detecting the reference signal, and applying a curve fitting method from which the distortion is calculated.

Abstract: A wavelet domain watermark encoder and decoder embed and detect auxiliary signals in a media signal, such as a still image, video or audio signal. A watermark orientation signal is embedded in a wavelet decomposed signal to facilitate detection of the watermark in a geometrically distorted version of the embedded signal. In some configurations, the watermark signal forms a pattern in a transform domain used to perform synchronization of the watermark. The pattern has attributes used to determine orientation of the watermark in a geometrically distorted version of the media signal. The attributes carry two or more auxiliary message symbols in the watermark, and the attributes both carry the two or more auxiliary message symbols and form the pattern used to perform synchronization of the watermark.

Abstract: The disclosure describes a method of progressively decoding a digital watermark on a distributed computing platform. A client device equipped with a digital camera, such as a PDA or cell phone, captures a digital image of a watermarked object, and pre-filters the image to isolate a portion of the image data suspected of containing a digital watermark. The pre-filter de-correlates a portion of the image data suspected of containing a digital watermark from the remaining host image signal using a predictive filter. The client then quantizes the filtered data and progressively transmits the quantized data to a watermark decoder. The progressive transmitter sends image data as necessary to achieve a valid decoding operation. To reduce bandwidth requirements, the transmitter starts with the most highly quantized version of the filtered image, and sends lesser quantized versions until the watermark decoder completes a successful decoding operation.

Abstract: A curve fitting method is used to synchronize a reader of embedded data in a media signal. A circular reference signal is embedded in the media signal. After geometric distortion of the media signal, the reference signal is distorted, yet still detectable. The amount of distortion is derived by detecting the reference signal, and applying a curve fitting method from which the distortion is calculated.

Abstract: This disclosure describes a method for encoding a digital watermark into an image signal that is robust to geometric distortion. The digital watermark is adapted to the host image signal in which it is embedded so as to be imperceptible or substantially imperceptible in the watermarked image when displayed or printed. This digital watermark may be used to determine the geometric distortion applied to a watermarked image, may be used to carry auxiliary information, and may be used to detect and decode a digital watermark embedded in a geometrically distorted version of a watermarked image. Because of its robustness to geometric distortion, the digital watermark is useful for a number of applications for embedding auxiliary data in image signals, including still pictures and video, where the image signal is expected to survive geometric distortion. This method may adapted to other types of media signals such as audio.

Abstract: The present invention detects the presence of a digital watermark in an image by selecting regions within the image having a high probability of containing the watermark. The image is examined to determine which regions of the image have characteristics indicating that there is a high probability that a watermark signal can be detected in that region of the image. The regions that have a high probability that a watermark can be detected (in contrast to all regions of the image) are examined to find watermark data. Probability factors used to select detection regions include: requiring a minimum variance separation between detection blocks; requiring a minimum distance between overlapping blocks; segmenting the detection blocks into a first and second subset based on separate criteria; establishing a keep away zone to prevent selection of a detection block near an image's border; and selecting a detection block only after its neighbors met sufficient threshold requirements.

Abstract: Utilizes pre-processing (pre-filtering) of target data in order to facilitate and enable robust extraction of a watermark signal. With the present invention the watermarked data is pre-filtered using knowledge of the watermark signal. That is, utilizing knowledge of the characteristics of the watermark signal (for example that it falls in a certain frequency range), aspects or portions of the signal that do not carry the watermark signal are eliminated by filtering. Such filtering can amplify the watermark signal and/or simultaneously reduces the strength of the original (host) content or noise in the data signal that contains the watermark. That is, pre-filtering increases the signal-to-noise ratio of the watermark signal and facilitates the watermark extraction steps (detection and decoding). With the present invention it is possible to extract weak watermark signals from target data.

Abstract: Steganographic calibration signals (sometimes termed “orientation signals,” “marker signals,” reference signals,” “grid signals,” etc.) are sometimes included with digital watermarking signals so that subsequent distortion of the object thereby marked (e.g., a digital image file, audio clip, document, etc.) can later be discerned and compensated-for. Digital watermark detection systems sometimes fail if the object encompasses several separately-watermarked components (e.g., a scanned magazine page with several different images, or photocopy data resulting from scanning while several documents are on the photocopier platen). Each component may include its own calibration signal, confusing the detection system. In accordance with certain embodiments, this problem is addressed by a proximity-based approach, and/or a multiple grid-based approach. In accordance with other embodiments, the calibration signal can—itself—convey watermark information, so it serves both a calibration and a payload-conveyance function.