摘要:
Various improvements to steganographic systems, and applications therefore, are disclosed. The improvements include facilitating scale and rotation registration for steganographic decoding by use of rotationally symmetric steganographically embedded patterns and subliminal digital graticules; improved techniques for decoding without access to unencoded originals; improving robustness of steganographic coding in motion pictures and/or in the presence of lossy compression/decompression; and representing data by patterned bit cells whose energy in the spatial domain facilitates decoding registration. Applications include enhanced-security financial transactions, counterfeit resistant identification cards, fraud deterrent systems for cellular telephony, covert modem channels in video transmissions, photo duplication kiosks with automatic copyright detection, and hotlinked image objects (e.g. with embedded URLs) for use on the internet.
摘要:
A given data object can effectively contain both a graphical representation to a network user and embedded information, such as the URL address of another network node, thereby to permit the object itself to serve as an automated hot link. The underlying development tools and web site browsers create and identify such an object for use in a manner similar to a hot link, as provided on the World Wide Web.
摘要:
Technology is now available permitting consumers to make amateur- or even professional-grade copies of photographs. For wedding and portrait photographers, in particular, the business of making duplications is fundamental to their livelihoods. The threat of such copying is felt strongly. To redress these concerns, a machine-readable marking is provided on emulsion films, photographic papers, and the like. The marking encodes digital information, yet is essentially imperceptible to the human eye. A photographic duplication kiosk can be constructed to read this embedded information and, if warranted by the embedded information, to disable the kiosk's copying function. An exemplary embodiment pre-exposes the photographic product with a spatial domain representation of the embedded data, and may include rotationally symmetric one- or two-dimensional patterns. Numerous other implementations are similarly practical."
摘要:
A method and system are described for reducing the theft of wireless telephony services, such as cellular systems and PCS systems, altering voice data to steganographically embed verification data therein. The verification data comprises a plurality of symbols which are steganographically detected at the carrier facility to confirm authorized use of the wireless device.
摘要:
A method and a device for automatic verification of genuineness of a banknote or a document comprising a watermark is described. A two-part, doubly active capacitive sensor device (4, 6, 7) is used. A symmetry property of the sensor output signal is changed in a predetermined manner when a correct watermark is present in a coinciding position with shape-adapted capacitor electrodes (4, 6).
摘要:
A security document such as a credit card or the like has material adapted to be optically scanned arranged along a line in the document. A modulating structure such as a document paper thickness is disposed within the document so as to be positioned between the line and an optically scanning, light sensing device. Accordingly, light emitting material in the line of the card upon being scanned will have the light thereof modulated so as to produce a reproducible authenticating variable when said line is scanned by the light sensing device.
摘要:
In a method of detecting sheets which do not have a genuine watermark (i.e. watermarks which result from variations in fibre distribution introduced during manufacture) the absorption of ultra-violet radiation is measured for each sheet in the area in which the watermark is expected to be present, and the transmittance of light by this area of the sheet is also measured. Sheets for which the absorption measurement does not show a substantially constant value, and sheets for which the light-transmittance shows a substantially constant value over the said area, are rejected. The absorption measurement is preferably effected by measuring the reflectance of ultra-violet radiation by the sheet, but the transmittance of ultra-violet radiation or the fluorescence of the sheet in the presence of ultra-violet radiation can also be measured. The measured value for the area can be compared with a reference value obtained by a measurement of the same parameter outside the watermark area.
摘要:
The invention relates to a method, in which from two images of a security element, which are recorded with right-handed and left-handed circularly polarizing filters, a differential image is produced, on the basis of which the authenticity of the security element is tested, and an apparatus for carrying out the method.
摘要:
There is disclosed an apparatus for image reading or processing, that can precisely identify a particular pattern, such as of banknotes or securities of faithful copying of which is to be prohibited. The apparatus is provided with a detecting unit for detecting positional information of an original image, and a discriminating unit for extracting the pattern data of a certain part of the original image and discriminating whether the original image is the predetermined image, based on the similarity between the pattern data and the predetermined pattern.
摘要:
A digital signal is imperceptibly embedded into an input source signal, such as an image or video signal, to produce an encoded (sometimes termed "watermarked") signal. The principle of quasi-rotational symmetry is employed to facilitate detection of the embedded signal notwithstanding rotation of the encoded signal. Single or multiple degrees of symmetry can be employed. In another aspect, the digital signal is transformed to a frequency domain and phase-only filtered prior to its combination with the input source signal. In an illustrative embodiment, this filtering operation helps hide the digital signal within the source signal, and facilitates detection of the embedded digital signal even after the encoded signal has undergone various forms of corruption.