Abstract: Input data is converted into an image, and in the input image, an encryption region that is a region in which the image is to be encrypted. Meanwhile, on the basis of an encryption key, encryption key-related information that is information related to the encryption key is generated, and the encryption key-related information is embedded into the image in the encryption region, to generate a first intermediate image. Next, the first intermediate image is converted on the basis of the encryption key, to generate a second intermediate image. Then, the pixel values of the second intermediate image are converted so that the position of the encryption region can be specified. As a result of the conversion, an encrypted image in which the part corresponding to the encryption region in the input image is generated.

Abstract: An electronic watermark embedding device that embeds a graphic pattern representing information in image data includes a signaling feature period changing unit configured to change a period of signaling feature of a graphic pattern, a graphic pattern embedding unit configured to embed the graphic pattern in the image data as a period of the signaling feature changed by the signaling feature period changing unit, and an embedment region detecting unit configured to detect an embedding position where the graphic pattern is embedded from a region of the image data other than a background, whereby the signaling feature period changing unit changes the period of the signaling feature while maintaining the signaling feature when the image data undergo image enlargement or reduction processing, and the graphic pattern embedding unit embeds the graphic pattern in the embedding position on the region of the image data other than the background.

Abstract: An digital watermark embedding device including an interface unit configured to acquire content in a digital form and digital watermark information, the device includes, a codeword generating unit configured to generate a base codeword including a bit sequence including the digital watermark information; a shifting unit configured to generate a plurality of correcting codewords differing from one another by permutating an arrangement in the bit sequence included in the base codeword depending on a plurality of shift amounts, the plurality of shift amounts differing from one digital watermark information to another, under a predetermined permutation rule; and a watermark superimposing unit configured to embed the plurality of correcting codewords in the content.

Abstract: An encrypting device generates an encrypted image by converting an image of a specified region in an input image with an encryption key, by embedding information obtained by encrypting the encryption key with a public key pairing with the private key of a destination, and by performing pixel value conversion. Then, the encrypted image is transmitted to the destination as a printed matter or via a network. A decrypting device converts the encrypted image in the form of print data or electronic data into an image, and inputs it. Next, the decrypting device extracts a decryption key (the encryption key) from the image of the encryption region by executing a process reverse to that of the encrypting device for the encryption region of the converted encrypted image. Then, the decrypting device decrypts the original image of the encrypted region by using the decryption key, and restores the entire encrypted image.

Abstract: A prediction error generating unit generates a predictive vector from the motion vectors of a plurality of adjacent blocks, and obtains a difference from a target vector. A plurality of variable-length coding units respectively encode the output of the prediction error generating unit with different encoding methods. A determining unit estimates the accuracy of the predictive vector generated by the prediction error generating unit based on the degrees of non-uniformity of the motion vectors of the plurality of adjacent blocks. A selecting unit selects one of the encoding results obtained by the plurality of variable-length coding units.

Abstract: An image encryption system includes an encrypter configured to generate an encrypted image including an encrypted area by encrypting a partial area of an input image; an identification information generator configured to generate identification information for identifying the encrypted area based on an image of the encrypted area; and a registration unit configured to register the identification information and a decryption key for decrypting the encrypted area by making an association between the identification information and the decryption key.

Abstract: A marker attaching apparatus attaches to an image a positioning marker for detecting a specific area in the image, and includes: an area size detection unit detecting a size of an area to which the positioning marker is attached; a marker adjustment unit adjusting the positioning marker depending on the detected size of the area; and a marker attaching unit attaching the adjusted positioning marker to the image.

Abstract: An image encryption apparatus encrypts a digital image by specifying a partial region from the digital image, converting the selected partial region into a processing image based on an encryption key, and specifying a position of the partial region by regularly converting a pixel value of the processing image.

Abstract: A digital-watermark embedding device includes a content obtaining unit that obtains content; a watermark-information obtaining unit that obtains digital-watermark information; a generating unit that generates a synchronization flag on a basis of the digital-watermark information; and an embedding unit that embeds the digital-watermark information and the synchronization flag into the content.

Abstract: In order to encrypt a part of an input image in such a manner that the encrypted part can be located for decryption, means for regularly converting pixel values in the area to be encrypted and generating a pattern unique to the pixel value conversion in order to encrypt the area to be encrypted; means for setting a specified positioning marker for locating an encryption position at two or more of the four corners of the area to be encrypted; and means for setting one or more checking marks for verifying appropriateness of a decrypted image in the encrypted area before the decryption are included.

Abstract: A prediction error generating unit generates a predictive vector from the motion vectors of a plurality of adjacent blocks, and obtains a difference from a target vector. A plurality of variable-length coding units respectively encode the output of the prediction error generating unit with different encoding methods. A determining unit estimates the accuracy of the predictive vector generated by the prediction error generating unit based on the degrees of non-uniformity of the motion vectors of the plurality of adjacent blocks. A selecting unit selects one of the encoding results obtained by the plurality of variable-length coding units.

Abstract: In an image encryption apparatus, an input processor inputs data of an input image. An encryptor encrypts a part or whole of the data of the input image. A marker generator generates data of a marker indicating an encrypted area. An image saver saves data of a marker-covered image covered with the marker. A marker sticker sticks the marker. An output processor outputs an encrypted image. In an image decryption apparatus, an input processor inputs data of an input image. A marker detector detects a marker and identifies an encrypted area. A decryptor decrypts data in the encrypted area. An image restorer restores data in an area covered with the marker by sticking data of a marker-covered image. An output processor outputs data of a decrypted image.

Abstract: An apparatus includes: a generator which generates a first pattern including a plurality of pixels having a first value, with an area of the first pattern changing in a constant cycle, and, a phase of cyclical change of the area changing based on a value of a symbol included in an inputted digital watermark information; a generator which generates a second pattern including a plurality of pixels having a second value, with an area of the second pattern changing with a frequency characteristic that is different from the cycle of change of the area; and a unit which superimposes the first and the second pattern into each image area of images in time series constituting an inputted video image to correct a value of each pixel in an image area to which the first or the second pattern is superimposed according to the first and the second value.

Abstract: A prediction error generating unit generates a predictive vector from the motion vectors of a plurality of adjacent blocks, and obtains a difference from a target vector. A plurality of variable-length coding units respectively encode the output of the prediction error generating unit with different encoding methods. A determining unit estimates the accuracy of the predictive vector generated by the prediction error generating unit based on the degrees of non-uniformity of the motion vectors of the plurality of adjacent blocks. A selecting unit selects one of the encoding results obtained by the plurality of variable-length coding units.

Abstract: An image decryption apparatus includes: an interface unit that acquires an encrypted image; and a processor adapted to: specify a block not presenting unevenness in brightness and a block presenting unevenness in brightness, among a plurality of first blocks into which the encrypted image is divided, and generate a decrypted image by moving each pixel of the encrypted image, in accordance with a predetermined rule; select, from among the second blocks located near the block of interest in a plurality of second blocks into which the decrypted image is divided, at least one second block that is included in the block not presenting unevenness in brightness on the encrypted image prior to generation of the decrypted image, as a reference value calculation block; and correcting the value of each pixel included in the block of interest, using the values of pixels included in the reference value calculation block.

Abstract: A prediction error generating unit generates a predictive vector from the motion vectors of a plurality of adjacent blocks, and obtains a difference from a target vector. A plurality of variable-length coding units respectively encode the output of the prediction error generating unit with different encoding methods. A determining unit estimates the accuracy of the predictive vector generated by the prediction error generating unit based on the degrees of non-uniformity of the motion vectors of the plurality of adjacent blocks. A selecting unit selects one of the encoding results obtained by the plurality of variable-length coding units.

Abstract: An image processing system includes: an image input unit which reads an image printed on a medium and generates electronic data representing the image; and a processing unit which corrects the image represented by the electronic data. The processing unit implements the functions of: detecting, from the image represented by the electronic data, a first pattern having a first size and shape that is attached to the image; measuring a degree of degradation by measuring an amount of displacement of the size of the detected first pattern from the first size; and correcting the image represented by the electronic data to reduce the degree of degradation.

Abstract: In an image encryption apparatus for visually encrypting an input image, an encryption area selector selects an encryption area within an input image including an area to be encrypted. An image converter divides the encryption area into a plurality of blocks. The image converter divides each block of the encryption area into a plurality of sub-blocks. An image converter performs an image conversion including rotation and mirror-reverse in accordance with an encryption key on the image in each sub-block. The image converter scrambles the image on a block-by-block basis in accordance with the encryption key. A pixel value converter converts a pixel value of a minimal area in a block so that a position of the block may be detected.

Abstract: A plurality of background texture patterns each of which includes a region not having a dot and having a feature different from those of the other background texture patterns, are combined, and information is embedded in a background region of a document image. Then, a mathematical-morphology-based conversion is performed on the document image, and thereby a feature of a region not having a dot in each of the background texture patterns is extracted in order to identify the embedded information.

Abstract: An digital watermark embedding device including an interface unit configured to acquire content in a digital form and digital watermark information, the device includes, a codeword generating unit configured to generate a base codeword including a bit sequence including the digital watermark information; a shifting unit configured to generate a plurality of correcting codewords differing from one another by permutating an arrangement in the bit sequence included in the base codeword depending on a plurality of shift amounts, the plurality of shift amounts differing from one digital watermark information to another, under a predetermined permutation rule; and a watermark superimposing unit configured to embed the plurality of correcting codewords in the content.