Abstract:
A method of producing a digital multiple-level encoded image is presented. The method comprises obtaining a digital authentication image, obtaining a first encoding parameter set comprising one or more encoding parameters, and constructing a first encoded image. The first encoded image is constructed using a first encoding methodology, the digital authentication image and the first encoding parameter set. The method further comprises obtaining a second encoding parameter set comprising one or more encoding parameters and constructing a second encoded image using a second encoding methodology, the first encoded image and the second encoding parameter set. The second encoded image may be decoded to reveal the first encoded image using a decoder having characteristics corresponding to at least a portion of the encoding parameters of the second encoding parameter set. The first encoded image may be decoded to reveal the authentication image using a decoder having characteristics corresponding to at least a portion of the encoding parameters of the first encoding parameter set.
Abstract:
The present invention is a method (Fig. 1) for hiding data in document contents. The method comprises receiving information relating to the document contents, (102) , wherein at least part of the document contents are of a binary nature, converting the data to halftone pixel groups according to predefined binary classifications associated with combinations of halftone pixels, (104), and embedding the halftone pixel groups into a binary portion of the document contents (104 and 114). Further, the present invention is a method for extracting data hidden in document contents (Fig. 7) The method comprises receiving information relating to the document contents (702), wherein the document contents include halftone pixel groups, extracting the halftone pixel groups from the document contents (712), and converting the halftone pixel groups to the data according to predefined binary classifications associated with combinations of halftone pixels (714).
Abstract:
Systems and method of detecting halftone modulations that are embedded in an image (18) are described. The halftone modulations represent an ordered sequence of digital halftone microscreens (46) that encodes information (14) that has been embedded in the image (18). In one embodiment, the embedded information (14) is detected by applying a respective matched filter (82) to the image (18) for each of two or more different halftone modulations to identify the ordered sequence of halftone modulations embedded in the image (18). This approach provides an effective, robust and efficient scheme for detecting such halftone modulations without knowledge of the original image (16) before halftone modulation.
Abstract:
A forensic verification system (700) extracts a print signature via print signature extractor (710) from the boundary of a halftone contained in an image. The system (700) compares the print signature to a reference signature stored in a registry via comparator (720) to determine differences between the print signature and the reference signature. The system (700) performs a forensic-level statistical image analysis via forensic analyzer (730) on the print signature and the reference signature based on the comparison to authenticate the printed media.
Abstract:
A method is provided for encoding a latent image having at least two color components into a visible image. A first and second image associated with first and second color components, respectively, are generated. The first image has a first pattern of elements and the second image has a second pattern of elements that are manipulated based on a corresponding color component provided in the latent image. A first and a second angle are assigned to the first image and the second image, respectively. The first image and second image are aligned by orienting the first pattern of elements according to the first angle and second angle, respectively. The aligned first image and second image are superimposed to render an encoded image that is decoded using a decoder that simultaneously display the first color component and the second color component of the latent image to present a color composite image.
Abstract:
A parallel test payload (10) includes a bit sequence configured to be segmented into a plurality of sub-sequences (14, 16, 18) having variable bit length carriers. Respective carriers (C0, C1, C2, C3, C4, C5, C6 and/or C7) are represented uniformly in each one of the plurality of sub-sequences (14, 16, 18).
Abstract:
A hidden image method comprising: obtaining a first image and a second image, the first and second images providing between them a hidden image and a decoder such that a hidden image is decoded by the decoder when the first image and the second image are superposed at at least one decoding position; printing the first image onto a light transmissive substrate to produce a printed substrate; displaying the second image on an electronic display; and superposing the printed substrate relative to the display at a decoding position to decode the hidden image.
Abstract:
A method and system for embedding data covertly in a text document using character rotation encoding. A character that occurs in first and second occurrences is selected, where the first occurrence of the character is a reference character and the second occurrence of the character as a rotatable character. The rotational orientation of the rotatable character is altered to produce an altered character with a predetermined rotation with respect to the reference character, wherein the rotation represents the embedded covert data. A text document is formatted based on the altered character.
Abstract:
A method and system for embedding data covertly in a text document using character rotation encoding. A character that occurs in first and second occurrences is selected, where the first occurrence of the character is a reference character and the second occurrence of the character as a rotatable character. The rotational orientation of the rotatable character is altered to produce an altered character with a predetermined rotation with respect to the reference character, wherein the rotation represents the embedded covert data. A text document is formatted based on the altered character.