Some implementations provide a computer-assisted method for embedding information in an identification document. The method includes: modulating information by varying lengths of line segments; generating a line code that includes the line segments with corresponding lengths; and applying the line code on an identification document such that the information is used to authenticate the identification document as genuine when a person presents the identification document to verify an identify of the person.

A method of encoding a watermark into a digital image is provided. The method includes partitioning an image into a plurality of blocks of a same size; accumulating the plurality of blocks of the same size into a single block image; performing a Fourier transformation on the single block image to obtain a two-dimensional Fourier spectrum defined by Fourier coefficients at different positions of a Fourier domain; inserting a watermark into a frequency domain of the two-dimensional Fourier spectrum by modifying the two-dimensional Fourier spectrum as a function of watermarking coefficients in the watermark, to obtain a modified Fourier spectrum; performing an inverse Fourier transformation on the modified Fourier spectrum to obtain a watermarked image; copying the watermarked image horizontally and vertically into a plurality of copied watermarked images; and splicing the plurality of copied watermarked images into a reconstituted watermark image.

Methods and apparatuses for watermark embedding and extracting are provided. A method for watermark embedding includes obtaining a carrier object and watermark information to be embedded in the carrier object; generating at least one encoding region including the watermark information according to the watermark information, the at least one encoding region including a plurality of template lattices; obtaining a watermark image according to the at least one encoding region; and embedding the watermark image in the carrier object.

Methods, devices, and computer-program products are provided for adding data to a digital video signal in a visually imperceptible manner. For example, a region of pixels can be identified in a video frame, and one or more pixel characteristics of the region of pixels can be determined. Based on the one or more pixel characteristics of the region of pixels, at least one pixel characteristic of a subset of pixels from the region of pixels can be modified in order to encode a set of data into the region of pixels. An output frame can be provided that includes the modified at least one pixel characteristics for the subset of pixels.

Some implementations may provide a method that includes: receiving, at a mobile device, data encoding a first digital watermark present on the identification document; extracting a first portion of personally identifiable information encoded by a spatial luminance pattern associated with the first digital watermark; receiving, at a mobile device, data encoding a second digital watermark present on the identification document; extracting a second portion of personally identifiable information encoded by a spatial luminance pattern associated with the first digital watermark; and validating the identification document based on at least one of the first portion of personally identifiable information or the second portion of personally identifiable information.

An identification document including a multilayer laminate having a core layer defining an opening therethrough, and a dynamic window in the opening. The dynamic window includes an optically variable coating on at least a front or a back of the dynamic window. The optically variable coating appears transparent when viewed from the front of the identification document in light transmitted through the dynamic window from the back of the identification document toward the front of the identification document, and appears nontransparent when viewed from the front of the identification document in light reflected from the front of the identification document. Fabricating an identification document with a dynamic window includes forming an opening in a core layer, positioning a dynamic window in the opening, and plate laminating the core layer and the dynamic window between at least one outer layer on each side of the core layer.

Methods, apparatus and articles of manufacture (e.g., computer readable media) to detect watermark modifications are disclosed. Example apparatus disclosed herein include means for encoding a first watermark in a first media signal obtained from an output of a media device to obtain a second media signal encoded with the first watermark and a second watermark, the second watermark already encoded in the first media signal obtained from the output of the media device. Disclosed example apparatus also include means for decoding the first watermark and the second watermark from the second media signal to determine a first metric corresponding to the first watermark and a second metric corresponding to the second watermark. Disclosed example apparatus further include means for outputting, based on the first metric and the second metric, an indication of whether the second watermark has been modified.

Certainty of detecting a watermark embedded in a color image is increased. Image data acquisition means of an image processing device acquires image data. Histogram generation means generates, based on pixel values of an image indicated by the image data acquired by the image data acquisition means, a histogram for each region in the image. Region selection means selects tom the image a region having a sparse color distribution in the histogram generated by the histogram generation means. Image processing means embeds a watermark in the region selected by the region selection means.

This application relates to the field of digital watermark technologies and discloses a digital watermark embedding method and extraction method, a digital watermark embedding apparatus and extraction apparatus, and a digital watermark system. The method includes obtaining a digital watermark of a composite file, splitting the digital watermark into N sub-watermarks according to a carrier quantity N of the composite file, each sub-watermark being corresponding to partial content of the digital watermark, embedding an i.sup.th sub-watermark in an i.sup.th carrier of the composite file, to obtain an i.sup.th target carrier, and integrating N target carriers into a target file. This application resolves a problem in the related technology that a digital watermark technology cannot ensure integrity of an order file, and protects carriers of a composite file, thereby ensuring security and integrity of the composite file.

This disclosure relates to advanced signal processing technology including steganographic embedding and digital watermarking. One combination disclosed in the description includes an image processing method. The method includes: obtaining an image comprising a plurality of color channels; for each color channel of the plurality of color channels, creating a grayscale version of the color channel and creating an inverted greyscale version of the color channel; analyzing the grayscale inverted version and the grayscale non-inverted version to locate image areas including an encoded signal, said analyzing yielding a plurality of image areas; generating one or more detectability measures corresponding to the encoded signal for each of the plurality of image areas; for each color channel selecting only one (1) image area as a validation point based on one or more generated detectability measures for that color channel; and generating information associated with a spatial location of each of the validation points in the image. Of course, other features and combinations are described as well.