摘要:
Multiple transform utilization and applications for secure digital watermarking. In one embodiment of the present invention, digital blocks in digital information to be protected are transformed into the frequency domain using a fast Fourier transform. A plurality of frequencies and associated amplitudes are identified for each of the transformed digital blocks and a subset of the identified amplitudes is selected for each of the digital blocks using a primary mask from a key. Message information is selected from a message using a transformation table generated with a convolution mask. The chosen message information is encoded into each of the transformed digital blocks by altering the selected amplitudes based on the selected message information.
摘要:
A watermarking system includes an encoding data processor operable to generate at least one marked version of an original item of material by introducing one of a predetermined set of code words into a copy of the original material item. The apparatus has a code word generator operable to provide the code word having a plurality of code word coefficients, and an encoding processor operable to combine the code word coefficients with the material. Each of the plurality of code words of the set is uniquely associated with a data word having first and second fields. Each of a set of values of the first field is represented as a first part of the code word having a first plurality of coefficients, and the second field is represented as a second part of the code word having a second plurality of coefficients.
摘要:
An electronic watermark data insertion apparatus comprises an insertion information memory (39) for preliminarily storing insertion information for designating electronic watermark data to be inserted block by block and an electronic watermark data insertion unit (33) for inserting, on the basis of the insertion information, the designated electronic watermark data from an electronic watermark data table (37) in a quantized image block by block. An electronic watermark data detection apparatus comprises an electronic watermark date extracting unit (45) for extracting the image data having a biased frequency region projecting in dependency on the inserted electronic watermark data block by block and an electronic watermark data detection unit (50) for calculating a statistical similarity between the extracted data and the electronic watermark data stored in an electronic watermark data table (48). An electronic watermark data accumulator (51) accumulates the statistical similarity for a predetermined time interval to produce an accumulated addition result which is reset after the elapse of the predetermined time interval or when the accumulated addition result exceeds the a predetermined threshold value. A determining unit (52) determines that the electronic watermark data is detected when the accumulated addition result exceeds the predetermined threshold value.
摘要:
Multiple transform utilization and applications for secure digital watermarking. In one embodiment of the present invention, digital blocks in digital information to be protected are transformed into the frequency domain using a fast Fourier transform. A plurality of frequencies and associated amplitudes are identified for each of the transformed digital blocks and a subset of the identified amplitudes is selected for each of the digital blocks using a primary mask from a key. Message information is selected from a message using a transformation table generated with a convolution mask. The chosen message information is encoded into each of the transformed digital blocks by altering the selected amplitudes based on the selected message information.
摘要:
Multiple transform utilization and applications for secure digital watermarking. In one embodiment of the present invention, digital blocks in digital information to be protected are transformed into the frequency domain using a fast Fourier transform. A plurality of frequencies and associated amplitudes are identified for each of the transformed digital blocks and a subset of the identified amplitudes is selected for each of the digital blocks using a primary mask from a key. Message information is selected from a message using a transformation table generated with a convolution mask. The chosen message information is encoded into each of the transformed digital blocks by altering the selected amplitudes based on the selected message information.
摘要:
The present invention relates to a method and apparatus for authenticating various types of digital certificates by using a text embedding method. The execution of the present invention is divided into two case, one case including images in the certificate and another case not including the images in the certificate, according to the characteristics of the certificate. In the former case, a text embedding method is applied to images included in the certificate to embed a series of information text (a specific number of the certificate, and issuing organization, name of a person in charge, etc.) designated by a person who issues the certificate into the images. In the latter case, there is generated an image imperceptible to the human eve but having the same color as the ground color certificate.
摘要:
Watermark embedding is often used to identify multiple copies (Qi) of the same content (Q). Each copy (Qi) is provided with a different private watermark (Wi) which, for example, identifies the player on which that copy may be reproduced. Private watermarks can be hacked. Averaging two or more watermarked copies may cause any of the private watermarks to become undetectable. The watermark embedder (10) in accordance with the invention embeds a global (fixed) watermark (W) in addition to the private watermark (Wi). The global watermark is the same in each copy and therefore remains detectable. Its presence indicates that a private watermark shall be present as well. It can be used in a protocol like: no playback allowed if the global watermark is present and a private watermark is not found.
摘要:
The present invention is a method for hiding data in document contents. The method comprises receiving information relating to the document contents, 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, and embedding the halftone pixel groups into a binary portion of the document contents. Further, the present invention is a method for extracting data hidden in document contents. The method comprises receiving information relating to the document contents, wherein the document contents include halftone pixel groups, extracting the halftone pixel groups from the document contents, and converting the halftone pixel groups to the data according to predefined binary classifications associated with combinations of halftone pixels.
摘要:
Residue calculating sections respectively obtain residues which take a plurality of integers as modulus, with respect to a user ID. The plurality of integers are stored in modulus storage sections and are prime to each other. Based on these residues and parameters stored in a coding parameter storage section, component codes constructed by continuous sequences of 1 and 0 using a predetermined number of bits as a unit are respectively generated by component code generating sections. These component codes are concatenated by a concatenating section, thereby to obtain a code to be embedded, which constructs watermark information.
摘要:
An image processing device of the present invention includes a management section for storing an authentication level set in accordance with the volume of image processing which is predicted in accordance with at least one of day and time. When a request for image processing to image data is made, an authentication section changes the authentication level for user authentication in accordance with at least one of day and time. Then, in accordance with this authentication result, requested image processing is performed.