A method for authenticating digital information includes obtaining, in digital form, information for authentication; preparing the information for processing, such preparation including converting the information into a digital image; identifying segments of content in the digital image; grouping the segments of content into one or more segment groups; generating a marking sequence comprising shifting at least one of the one or more segment groups in one or more directions; and applying the marking sequence to the digital image, creating a unique marked copy of the digital image.

The present disclosure a method of providing identification code insertion service for tracking a duplicated image, which is performed by a server, including: (a) receiving an image from a user terminal; (b) converting the received image to black and white, and selecting a plurality of insertion regions in the converted image; (c) transforming an image of at least one of a plurality of insertion regions selected at random; and (d) mapping an identification code and image information included in the transformed image of the insertion region, storing the identification code and the image information in a database, and providing the image in which the identification code is inserted to the user terminal.

A system and method is provided for management of digital watermarks, including a system and method for identifying the source of counterfeit copies of multimedia works using layered simple digital watermarks which are difficult to locate, identify and circumvent. The layered digital watermarks may be modulated in a variety of ways, and may be individualized to assist in detection of unlawful copyrighted material infringement by endpoint device and/or the user committing the copyright infringement. In addition, multiple layers of watermarks may be selected and applied by various schemes, such as on-the-fly remotely by the distributor of the copyrighted material. This system and method for management of digital watermarks effectively makes it impossible for a potential copyright infringer to have complete confidence that they located and disabled all of the watermarks in the copyrighted material, and therefore substantially increases the risk of infringer identification and prosecution for copyright violations.

A method and an apparatus for controlling content integrity. A method for operating in an electronic device can include including unique information of content in a watermark image, and inserting the watermark image to the content.

A method for authenticating digital information includes obtaining, in digital form, information for authentication; preparing the information for processing, such preparation including converting the information into a digital image; identifying segments of content in the digital image; grouping the segments of content into one or more segment groups; generating a marking sequence comprising shifting at least one of the one or more segment groups in one or more directions; and applying the marking sequence to the digital image, creating a unique marked copy of the digital image.

Signal processing devices and methods estimate a geometric transform of an image signal. From a seed set of transform candidates, a direct least squares method applies a seed transform candidate to a reference signal and then measures correlation between the transformed reference signal and an image signal in which the reference signal is encoded. Geometric transform candidates encompass differential scale and shear, which are useful in approximating a perspective transform. For each candidate, update coordinates of reference signal features are identified in the image signal and provided as input to a least squares method to compute an update to the transform candidate. The method iterates so long as the update of the transform provides a better correlation. At the end of the process, the method identifies a geometric transform or set of top transforms based on a further analysis of correlation, as well as other results. Phase characteristics are exploited in the process of updating coordinates and measuring correlation. The geometric transform is used as an approximation of the geometric distortion of an image after digital data is encoded in it, and is used to compensate for this distortion to facilitate extracting embedded digital messages from the image. Due to the errors in the approximation, a signal confidence metric is determined and used to weight message symbol estimates extracted from the image.

A method for verifying the integrity, continuity, and availability (ICA) of information displayed on an uncertified display is disclosed. The method includes creating application data for display on the uncertified display device that includes a subliminal symbol that is periodically embedded in a few out of multiple tens of frames and that is camouflaged in the application data using steganography; transmitting the application data to the uncertified display device for display; receiving images of the application data displayed on the display screen; determining whether the subliminal symbol is detected in the captured images by extracting the symbol from the captured images and comparing the extracted symbol to an expected symbol; determining that the application data is not corrupted when the extracted symbol matches the expected symbol; and identifying a loss of ICA when the subliminal symbol is not detected or does not match the expected symbol.

A method for verifying the integrity, continuity, and availability (ICA) of information displayed on an uncertified display is disclosed. The method includes creating application data for display on the uncertified display device that includes a subliminal symbol that is periodically embedded in a few out of multiple tens of frames and that is camouflaged in the application data using steganography; transmitting the application data to the uncertified display device for display; receiving images of the application data displayed on the display screen; determining whether the subliminal symbol is detected in the captured images by extracting the symbol from the captured images and comparing the extracted symbol to an expected symbol; determining that the application data is not corrupted when the extracted symbol matches the expected symbol; and identifying a loss of ICA when the subliminal symbol is not detected or does not match the expected symbol.

The geometric pose of a patch of watermark data is estimated based on the position of a similar, but non-identical, patch of information within a data structure. The information in the data structure corresponds to a tiled array of calibration patterns that is sampled along at least three non-parallel paths. In a particular embodiment, the calibration patterns are sampled so that edges are globally-curved, yet locally-flat. Use of such information in the data structure enables enhanced pose estimation, e.g., speeding up operation, enabling pose estimation from smaller patches of watermark signals, and/or enabling pose estimation from weaker watermark signals. A great variety of other features and arrangements are also detailed.

Provided is a method for reconstructing content image data. The method includes selecting a first point and a second point in a first image of first content, selecting a third point and a fourth point in a second image of second content (the second image is an image corresponding to the first image and the third point and the fourth point are points in an image corresponding to the first point and the second point, respectively), generating a first reference vector using the first point and the second point, generating a second reference vector using the third point and the fourth point, calculating a rotation, scale, and transformation (RST) value from the first image to the second image using the first reference vector and the second reference vector; and reconstructing the second content using the calculated RST value.