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.

Abstract: Briefly, in accordance with one embodiment of the invention, a video processing system includes: a video coder. The video coder includes the capability to generate an edge detection map along a predetermined direction for an uncoded frame that is to be coded. Briefly, in accordance with another embodiment of the invention, an article includes: a storage medium having stored thereon instructions capable of being executed by a system that when executed result in: producing an edge detection map along a predetermined direction from the video frame prior to coding; and coding the edge detection map and the video frame. Briefly, in accordance with one more embodiment of the invention, a method of processing a video frame includes: producing an edge detection map along a predetermined direction from the video frame prior to coding; and coding the edge detection map and the video frame.

Abstract: Registration data embedded in an image is used to determine and compensate for geometric transformation of the image. The registration data may include frequency domain features of the image that are used to compute the rotation and/or scaling of the image. The registration method may be used in conjunction with digital watermarking and other signal processing applications.

Abstract: This disclosure describes methods for using embedded auxiliary signals in documents for copy detection and other applications. In on application, the auxiliary signal is formed as an array of elements selected from a set of print structures with properties that change differently in response to copy operations. These changes in properties of the print structures that carry the embedded auxiliary signal are automatically detectable. For example, the changes make the embedded auxiliary signal more or less detectable. The extent to which the auxiliary data is detected forms a detection metric used in combination with one or more other metrics to differentiate copies from originals. Examples of sets of properties of the print structures that change differently in response to copy operations include sets of colors (including different types of inks), sets of screens or dot structures that have varying dot gain, sets of structures with different aliasing effects, etc.

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: Various improvements and applications for digital watermarking technology are detailed. One concerns techniques for making watermarks resistant to malicious attacks. Another involves using digital watermarking with ID cards and credentials, such as a watermarked driver's license conveying a user's cryptographic PKI. Still another uses digital watermarks in connection with automated compliance audits for corporate users of electronic content. A variety of other technologies are also detailed.

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: To enhance decoding of signals suspected of containing an embedded auxiliary signal, a suspect signal is screened to compute detection values evincing presence and strength of the embedded signal. Screening strategies control detector actions, such as rejecting un-marked signals, improving synchronization of a reader used to extract hidden messages in suspect signals, determining authenticity of signals, and controlling use of the signals.

Abstract: A system (40) responsive to watermarked documents for exchanging data. The system (40) contains a user terminal (42) including a watermark reader, and a capture device to capture an image of a watermark document, and a central site (46) including a database of image hashes. The watermark reader reads a watermark and computes a hash of a captured image, and passes to hash to the central site (46) for comparison with the database of image hashes.

Abstract: A wavelet domain watermark encoder and decoder embed and detect auxiliary signals (1300, 1302) in a media signal (1306), such as a still image, video or audio signal. A watermark orientation signal (1302) is embedded in a wavelet decomposed signal (1304) to facilitate detection of the watermark in a geometrically distorted version of the embedded signal.

Abstract: A digital watermark reader performs a logarithmic sampling of a watermarked media signal to produce a sampled signal. It then analyzes the sampled signal to detect attributes associated with a watermark signal. It extracts a digital watermark based on detected attributes associated with the watermark signal. As an alternative or in addition to these operations, the watermark reader performs a polar sampling of the media signal. For example, polar sampling may be used to address rotational distortion. Another digital watermark reader transforms the media signal to a transform domain, and analyzes the transformed media signal to detect a symmetrical attribute associated with a watermark signal. The method extracts the digital watermark based on detected attributes associated with the watermark signal.

Abstract: To enhance decoding of signals suspected of containing an embedded auxiliary signal, a suspect signal is screened to compute detection values evincing presence and strength of the embedded signal. Screening strategies control detector actions, such as rejecting un-marked signals, improving synchronization of a reader used to extract hidden messages in suspect signals, determining authenticity of signals, and controlling use of the signals.

Abstract: A signal embedder hides auxiliary data in a media signal such that the auxiliary data is humanly imperceptible yet recoverable by an automated auxiliary data reader. The embedding method comprises segmenting the media signal into regions, determining statistics for the regions, and adapting quantization bins for each region based on the statistics calculated for the region. To hide auxiliary data in the regions, the method quantizes signal characteristics in the regions into the quantization bins adapted for the regions. The quantization bins correspond to auxiliary data symbols and the signal characteristics are quantized into selected bins depending on the auxiliary data symbol to be embedded in the signal characteristics. A compatible reading method performs a similar adaptive process to define the quantization bins before mapping signal characteristics into the adapted bins to extract the hidden data.

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 digital watermark reader performs a logarithmic sampling of a watermarked media signal to produce a sampled signal. It then analyzes the sampled signal to detect attributes associated with a watermark signal. It extracts a digital watermark based on detected attributes associated with the watermark signal. As an alternative or in addition to these operations, the watermark reader performs a polar sampling of the media signal. For example, polar sampling may be used to address rotational distortion. Another digital watermark reader transforms the media signal to a transform domain, and analyzes the transformed media signal to detect a symmetrical attribute associated with a watermark signal. The method extracts the digital watermark based on detected attributes associated with the watermark signal.

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: 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: The error rate of auxiliary data embedded in media signals is decreased through variable error robustness coding. In one application, error correction coded symbols in a steganographic message that are more prone to error are repeated more than other symbols. In another application, the error robustness coding is increased or decreased in different parts of an auxiliary data message according to a measure of the expected error rate based on a model of the channel and/or the host media signal that is to carry the auxiliary data through that channel.

Abstract: To enhance decoding of signals suspected of containing a watermark, a suspect signal is screened to compute detection values evincing presence and strength of a watermark. Screening strategies control detector actions, such as rejecting un-marked signals and improving synchronization of watermarks in suspect signals.

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.