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: 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: 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: A digital watermark embedding apparatus includes an interface unit which acquires video data and digital watermark information, and a processing unit which embeds the digital watermark information into the video data. The processing unit is adapted to cause the area of a watermark pattern formed by a plurality of pixels having a prescribed value, and superimposed on each image contained in the video data, to vary in periodic fashion over time according to the value of a symbol contained in the digital watermark information, and correct, using the prescribed value, the value of each pixel contained in a region where each image in the video data and the watermark pattern corresponding to that image overlap each other.

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: At the time of marker attachment (at the time of encryption), for example, image conversion in which pixels to be overwritten by a marker are selected and pruned in a distributed manner and the pruning positions are moved to a marker attachment position is performed, and the marker is attached to the marker attachment position obtained as a result. At the time of marker elimination (at the time of decryption), for example, image reverse conversion in which each pixel of the marker is moved to the original position before the marker attachment is performed, each moved pixel of the marker is recovered, and the marker is eliminated.

Abstract: When a decrypting apparatus receives an encrypted image, the apparatus detects the state of the encrypted image and determines whether the encrypted image is an image passed through only a digital medium or an analog medium, according to the state of the encrypted image. When the encrypted image is determined to be the image passed through only the digital medium, the decrypting apparatus switches to perform a digital decryption process and, when the encrypted image is determined to be the image passed through the analog medium, the decrypting apparatus switches to perform an analog decryption process.

Abstract: A figure pattern expressing information to be embedded, or a position of an area in which the information to be embedded exists, is embedded in an area other than the background of image data, thereby generating image data embedded with a watermark. Then, the figure pattern is detected from the generated image data embedded with the watermark, and embedded information expressed by the detected figure pattern or embedded information existing in an area at a position expressed by the detected figure pattern is detected.

Abstract: When creating a marker, an encryption apparatus extracts each pixel value in a region and allows a storing unit to save, as restoration information, the high-order bits of each extracted pixel value. Then, the encryption apparatus creates a marker by changing the high-order bits of the pixel value in a region in which the marker is created and embeds encrypted information in an encrypted region specified by the marker. When decoding the encrypted information, a decoding apparatus detects the marker from a digital image, decodes the encrypted information in the encrypted region specified by the marker, and overwrites bits contained in the restoration information with the high-order bits of the pixel value of the marker.

Abstract: An image processing device includes, a block division unit configured to divide at least a part of an area of an input image into a plurality of blocks; a block classification unit configured to classify each block in the input image into a white block and a black block based on a variance of luminance values in a white block that typically includes white pixels and a variance of luminance values in a black block that includes at least black pixels among white pixels and black pixels; and a luminance correction unit configured to correct a luminance value of each pixel in a black block in the input image based on an average luminance value of pixels in one or more white blocks in the vicinity of the black block.

Abstract: Provided is a digital watermarking technology for embedding digital watermark information in text data thereby to generate a digitally watermarked image. The technology includes a digital watermarking program, a digital watermarking device and a digital watermarking method, in which digital watermark information can be embedded in document in such a way as not to be easily detected visually and be stably detected even after being printed out, copied or scanned by detecting the features of a character as data to be digitally watermarked, such as the direction and thickness of a line composing the character as the features thereof and embedding the digital watermark information in the character on the basis of the detected features.

Abstract: Constraints are added to the size of an encryption area at the time of encryption processing. For example, if the respective number of horizontal and vertical divided blocks is divided by a predetermined positive integer, the size of the encryption area is limited such that the remaining is a certain number of 0 (namely, a multiple of the predetermined positive integer to the respective number of blocks) or 1 or more. Block positions in the encryption area are detected according to the constraints of the number of blocks of an encryption image as the decryption processing corresponding to the encryption processing. Because the number of horizontal and vertical blocks is previously limited at the time of the encryption, the possibility of the number of blocks to be considered in the detection of the block positions is reduced, resulting in improved decryption accuracy.

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: An image processing apparatus includes: an interface unit for acquiring a readout image produced by capturing an image formed on a medium; a storage unit for storing a plurality of templates generated by superimposing different amounts of blurring on a prescribed pattern contained in the image, and for storing the amounts of blurring superimposed on the respective templates; and a processing unit adapted to detect a pattern region where the prescribed pattern is located on the readout image, calculate the degree of matching between the pattern region and each of the plurality of templates and, based on the degree of matching, identify a template that most closely matches the prescribed pattern located on the readout image, and estimate that the amount of blurring corresponding to the most closely matching template represents the amount of blurring superimposed on the readout image.

Abstract: A marker placement device includes, a marker placement method decision section that decides, for every predetermined pitch from a starting edge of a side to an end edge of the side, a placement position of a marker for detecting a position within a rectangular image region, the placement position being along the side of the image region within an image. A marker adding section that adds the marker to the image according to the placement position decided is provided, where, when a gap shorter than the pitch remains between the end edge and the decided placement position closest to the end edge of the side, the marker placement method decision section decides a first marker placement position closest to the starting edge, and decides a subsequent marker placement position.

Abstract: A high-definition magnified image is obtained by simple computation. A magnified image is obtained by obtaining a deteriorated image on the basis of an input original image, determining enhancement filters used for individual small areas of the original image using the deteriorated image at least, performing a filtering process by applying the filters thus determined to the individual small areas to achieve enhancement, and interpolating the image for magnification.

Abstract: An electronic document processing system 900 includes a digital image generating unit 15 generating a digital image in a predetermined range of the electronic document; an image encrypting unit 11 generating an encrypted image by converting at least a partial area of the generated digital image; a data encrypting unit 21 generating encrypted data by extracting data contained in the predetermined range in pieces of data organizing the electronic document and encrypting the data; an encrypted data storing unit 22 storing the encrypted data; and an encrypted electronic document generating unit 23 generating an encrypted electronic document by replacing the data contained in the predetermined range in the electronic document with the encrypted image.