Abstract: A verification information generation system comprises a first and a second data processing apparatuses.

Abstract: An apparatus receives a document image and digital-watermark information and determines an embedding capacity based on a number of the letters in the document image. The apparatus determines whether or not the entire digital-watermark information is capable of being embedded in the document image based on the determined embedding capacity and embeds the digital-watermark information in the document image based on a result of the determination of whether or not the entire digital-watermark information is capable of being embedded in the document image.

Abstract: An apparatus generates additional data used to check whether an encoded digital image is changed or not. The apparatus includes a calculation unit and a recording unit. The calculation unit (a) performs a predetermined calculation using the encoded digital image and confidential information and (b) generates the additional data by applying a one-way function to a result of the predetermined calculation. The recording unit records both the encoded digital image and the additional data on a recording medium. The confidential information includes (a) first information unique to the apparatus, and (b) second information unique to an external apparatus connected to the apparatus.

Abstract: The present invention aims to be able to provide an efficient public key digital watermark method which is specialized to information common to contents. In the method, arrangement order of digital data in input digital contents is set to become predetermined arrangement order so that the input digital contents constitute an error correction code.

Abstract: An apparatus for embedding a digital watermark in a document image detects circumscribing outer shapes of characters in the document image and sets a plurality of reference lines that extend in the column direction and are spaced apart in the row direction by a basic pitch. The outer shapes include a first outer shape, a second outer shape that neighbors the first outer shape, and a third outer shape that neighbors the second outer shape, and the reference lines include a first reference line located between the first outer shape and the second outer shape, and a second reference line located between the second outer shape and the third outer shape. Control is performed for at least one of the second and third outer shapes so that a distance between the first reference line and an edge of the second outer shape is different from a distance between the second reference line and an edge of the third outer shape, in accordance with digital watermark information to be embedded.

Abstract: An apparatus receives a document image and digital-watermark information and determines an embedding capacity based on a number of the letters in the document image. The apparatus determines whether or not the entire digital-watermark information is capable of being embedded in the document image based on the determined embedding capacity and embeds the digital-watermark information in the document image based on a result of the determination of whether or not the entire digital-watermark information is capable of being embedded in the document image.

Abstract: When determining whether or not an image of an original input from an image reading device is a copy-prohibition image, a mounting position, a mounting angle or the like of the original is detected, and it is determined whether or not exact determination can be performed. If an exact determination cannot be performed, a signal instructing to again read an image of the original is output, and the operator is provided with a warning.

Abstract: Distance d1 between the right edges of A1 and B2, and distance d2 between the right edges of A3 and B4 are calculated. If data to be embedded is 1, one or a combination of a process for increasing the size of B2 in the column direction or decreasing the size of B4 in the column and a process for moving the position of B2 toward B3 or moving the position of B4 toward B3 is executed to meet d1>d2. If data to be embedded is 0, one or a combination of a process for decreasing the size of B2 in the column direction or increasing the size of B4 in the column direction, and a process for moving the position of B2 toward B1 or moving the position of B4 toward B5 is executed to meet d1<d2.

Abstract: The secret data is acquired externally by making an arithmetic operation between unique information of an apparatus and the first information managed secretly, and secretly held as key data in a key holding part. A MAC generation part generates the authentication data based on a hash value obtained from the data to be protected and the key data held in the key holding part 21. An image file generation part generates an image file to provide the unique information and the authentication data together with the data to be protected.

Abstract: An object of the present invention is to assuredly provide image data with the position of a region of interest in an image represented by the image data. In order to achieve this object, position information for specifying a region of interest within the image is embedded so as not to be recognized by human eyes, using a digital-watermark technique.

Abstract: It is required to protect the copyrights and the like of partial images which form respective parts of an image obtained by reading an image, exchanged using a print as a medium, by an image scanner or the like. Input image data is divided into a plurality of image regions having different features, digital watermarks, which are embedded in the detected image regions by embedding methods corresponding to the features of the image regions, are extracted, and the availability of the input image is checked on the basis of the extracted digital watermarks.

Abstract: A digital watermark mark which is robust against alliance and average value attacks is embedded in data, and original data is protected from being tampered with. Image quality that may be obtained by an attacker by, e.g., an alliance attack is determined. In this case, LL3 is determined to be that image quality. A portion to be modified of high-image quality portions is determined. In this case, HL1 is determined as a high-image quality portion to be modified, and is entirely shifted rightward by 1 bit. Hence, prepared block images undergo wavelet transformation to be decomposed into frequency components, and HL1 as the selected high-image quality portion is modified. Upon completion of the aforementioned modification process, this block undergoes inverse wavelet transformation to reclaim the block image.

Abstract: A document image undergoes document analysis to obtain circumscribing rectangles of characters (S601), and two distances between non-neighboring circumscribing rectangles from the head of the document are respectively calculated as d1 and d2 (S603). If information to be embedded is 1, one or a combination of a process for changing a parameter associated with the size of a circumscribing rectangle and a process for changing a parameter associated with the position of a circumscribing rectangle is executed to satisfy d1>d2 (S605). If information to be embedded is 0, one or a combination of the above two parameter change processes is executed to satisfy d1<d2 (S606).

Abstract: The invention extracts third information, which includes first and second information, from image data. The first information (e.g., copyright information) is embedded in the image data using a public embedding method, and the second information (e.g., information used to detect if the copyright has been altered) is embedded in the image data using a private embedding method. The first information is then extracted from the third information using the second information.

Abstract: In an information distribution processing system having a plurality of information processing apparatuses connected through a network, at least one of the plurality of information processing apparatuses can acquire distribution information to which is added first additional information as an electronic watermark using a first adding method, and second additional information as an electronic watermark using a second adding method. An extraction unit extracts the first additional information using the first adding method, and an identification unit identifies an information processing apparatus that is able to extract the second additional information, based on the first additional information.

Abstract: A provider side apparatus provides original digital data together with a digital signature generated by the provider side apparatus, the digital signature detecting whether the original digital data was falsified or detecting a change level given to the original digital data. Upon reception of the digital data, a receiver side apparatus can know the originality of the received digital data or a change level of the received digital data from the original digital data, in accordance with the digital signature corresponding to the digital data.

Abstract: A provider side apparatus provides original digital data together with a digital signature generated by the provider side apparatus, the digital signature detecting whether the original digital data was falsified or detecting a change level given to the original digital data. Upon reception of the digital data, a receiver side apparatus can know the originality of the received digital data or a change level of the received digital data from the original digital data, in accordance with the digital signature corresponding to the digital data.

Abstract: The invention is to precisely extract a digital watermark from image data which are subjected to embedding of the digital watermark in a state of a binary image and are then converted into a multi-value image (gray scale image). For attaining the foregoing object, a digital watermark extracting apparatus for extracting a digital watermark for example in an original includes an acquiring unit for acquiring multi-value image data obtained by reading the original with a predetermined reading unit, a pre-processing unit for selecting one of plural threshold values and binarizing the multi-value image data with the selected threshold value, and an extracting unit for extracting the digital watermark from image data binarized in the pre-processing unit, wherein selection of the threshold value, binarization an extraction of the digital watermark are repeated to obtain an optimum extraction result of the digital watermark.

Abstract: An encrypted image C(i, j) is generated by exclusively ORing pseudo random number values, which are generated using a key k0 as a key, and respective bits, except for the LSBs, of B pixel data at respective pixel positions (i, j) of digital image data I(i, j). First check bits B(i, j) corresponding to the pixel positions of pixels are generated based on the image C(i, j) and a conversion table. A digitally watermarked image I?(i, j) is obtained by embedding the first check bits in the LSBs of the corresponding pixel data of the digital image data. Check bits U(i, j) are obtained by encrypting pixel data by exclusively ORing respective bits, except for the LSBs, of B pixel data at positions (i, j) of the image I?(i, j) and the pseudo random numbers. If each check bit U(i, j) matches the LSB of the corresponding B pixel data, it is determined that the corresponding pixel is free from tampering.

Abstract: The primary objective of the present invention is the prevention, or the detection, of an illegal act involving digital contents. To achieve this objective, whether an illegal procedure involving digital contents has been performed is determined based on results obtained by performing a predetermined operation for at least a part of the digital contents, and a predetermined process is performed for the digital contents in accordance with the results of determination.