摘要:
A watermarking system comprises 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 code words are generated from a pseudo-random number generator initialised with a seed value. The seed value is used to identify the marked material item, from the code word produced from the seed value. The watermarking system also includes a detecting data processor operable to identify a particular marked copy of the material item by recovering a code word from the marked material item and correlating all code words in the set of code words with the recovered code word. The detecting data processing apparatus also includes a registration processor operable to associate samples of the original material item with corresponding samples of the marked material item to which corresponding code word coefficients may have been added. By registering the original material item with the marked material item, a likelihood of correctly identifying the version of the marked material item is improved, reducing a false negative detection probability.
摘要:
This invention provides an image processing apparatus and method, which embed a digital watermark having strong robustness against geometrical transformation/edit processes such as rotation, scaling, translation, and the like, and an image processing apparatus and method, which can accurately extract the embedded digital watermark even after the conversion/edit process such as rotation of an image or the like. A Fourier transformer (901) converts an image input from an image input unit (900) into amplitude component data, and phase component data. An envelope ring pattern generator (902) generates an embedding pattern of digital watermark information, which is expressed by a set of lines that define a circle as an envelope, on the amplitude component data. An envelope ring pattern embedding unit (903) embeds digital watermark information at predetermined positions on the line. An inverse Fourier transformer (904) computes the inverse frequency transforms of the amplitude component data embedded with the digital watermark information using the phase component data.
摘要:
Apparatus and an accompanying method, for generating a cryptographic identifier for a non-marked image and embedding that identifier within the image itself in order to generate a “watermarked” image; for subsequently detecting that watermark in a test image; and the watermarked image so formed. First, pixel values for a non-marked image are transformed, either directly or after being enhanced, into a series of transform coefficients. A set of pseudo-random perturbation values which collectively constitute the watermark is determined wherein each of these values is heuristically selected, such that all these values collectively satisfy a plurality of different mathematical constraints and each such value preferably equals a relatively small value in a predefined range. These perturbation values are then added to the transform coefficients. Resulting perturbed coefficients are then inversely transformed back to pixel values to form the watermarked image. To detect whether a test image contains the watermark and hence is a copy of the watermarked image, the pixel values for the test image are transformed to yield transform coefficients. A plurality of different mathematical tests or a majority type rule is then used, in conjunction with the perturbation values, previously used to create the watermark, and these transform coefficients to determine whether the perturbation values collectively exist in the test image, and hence whether the watermark is present or not.
摘要:
Method of embedding a watermark in a digital object. The watermark is used to perform argument modulation of a transform of the object. Watermark data is used in the argument of the transform to effectively shift around values in the transform domain.
摘要:
An electronic watermark system invisibly embeds watermark information into original image data and the watermarked image data is transferred to a first medium. At the same time. the embedded watermark information is transferred to a second mediums. When a medium questioned is found, its watermark information can be easily identified by searching the second medium. Alternatively, the watermarked image data and the embedded watermark information are transferred to different storage areas of the same medium, respectively.
摘要:
An electronic watermark system invisibly embeds watermark information into original image data and the watermarked image data is transferred to a first medium. At the same time, the embedded watermark information is transferred to a second medium. When a medium questioned is found, its watermark information can be easily identified by searching the second medium. Alternatively, the watermarked image data and the embedded watermark information are transferred to different storage areas of the same medium, respectively.
摘要:
A technique for hiding of data, including watermarks, in human-perceptible images, that is, image host data, is disclosed. In one embodiment a method comprises three steps. In the first step, data to be embedded is inputted. In the case of a watermark, this data is a unique signature, and may be a pseudo-noise (PN) code. In the case of hidden data to be embedded in the host data, this data is the hidden data itself, or the hidden data as spread against the frequency spectrum by a pseudo-noise (PN) code. In the second step, the inputted data is embedded within the host data, in accordance with a perceptual mask of the host data. The perceptual mask determines the optimal locations within the host data to insert the inputted data. In the case of images, these optimal locations are determined by reference to the human visual system. In the third step, the host data, with the embedded data, is further masked by a non-frequency mask. In the case of image data, the non-frequency mask is a spatial mask.
摘要:
Digital watermarking of data, including image, video and audio data, is performed by repeatedly inserting the watermark into subregions or subimages of the data. Similarly, the watermark is repeatedly extracted from the subregions of the data.
摘要:
A watermark is embedded into audio/video/image/multimedia data using spread spectrum methodology. The watermark is extracted from watermarked data without the use of an original or unwatermarked version of the data by using spatial or temporal local averaging of the frequency coefficients of the watermarked data.
摘要:
A device may capture an image in a portable device, embed a watermark into the image in the portable device, and transmit the watermarked image through a wireless interface of the portable device.