摘要:
Digital watermark methods for encoding auxiliary data into a host signal are used to authenticate physical and electronic objects. One such method computes a content specific message dependent on the host signal, encodes the content specific message into a watermark signal, and embeds the watermark in the host signal such that the watermark signal is substantially imperceptible in the host signal. One specific implementation embeds data representing salient features of the host signal into the watermark. For example, for photo IDs, the method embeds the spatial location of salient features of the photo into the watermark. Another implementation computes a semi-sensitive hash of the host signal, such as a low pass filtering of the signal, and embeds the hash into the watermark. The watermark signal may be content dependent by making the watermark key dependent on some attribute of the signal in which the watermark is embedded. Another approach is to make the watermark key dependent on a user or an attribute of the user. Yet another approach is to use multiple watermark components and multiple watermark detection stages that help identify and screen out invalid watermark signals. Another digital watermarking method for authenticating a media object transforms a media signal to a frequency domain comprising an array of frequency coefficients. It selects a first set of frequency coefficients, and alters the selected first set of frequency coefficients so that values of the coefficients in the set correspond to a pattern. The pattern of the media signal is authenticated by comparing a pattern of the values of the frequency coefficients in the set with an expected pattern.
摘要:
Digital watermark methods for encoding auxiliary data into a host signal are used to authenticate physical and electronic objects. In one implementation, an identification document includes electronic circuitry. The electronic circuitry includes an image of an authorized bearer of the identification document. The image includes first digital watermarking having a plural-bit identifier. In some cases, the identification document includes a printed image of the authorized bearer of the identification document. The printed image includes second digital watermarking therein. The first digital watermarking and the second digital watermarking can be cross-correlated for authentication of the identification document.
摘要:
A variety of systems and embodiments are disclosed. Some of the embodiments handle steganographic data. One embodiment provides a method including: launching on a first computer a reader to read embedded, hidden data; extracting identifying data from the embedded, hidden data; communicating at least the extracted identifying data to a second, remote computer to obtain: i) a URL or pointer associated with a third, remote computer, and ii) a ticket, wherein the URL or pointer is associated with the extracted identifying data; receiving the URL or pointer and the ticket at the first computer from the second, remote computer; using at least the URL or pointer, passing the ticket from the first computer to the third, remote computer to obtain a permission associated with the ticket; and upon receipt of the permission from the third, remote computer, passing the permission from the first computer to a fourth, remote computer.
摘要:
A peripheral device for use with a computer system includes a housing adapted to fit within a user's palm, an optical sensor, a lens, circuitry for processing the signals from the sensor and producing corresponding output data, and a wireless link for relaying the output data from the peripheral device to the computer system. The sensor is useful in acquiring optically-encoded multi-bit information for use by the computer system. Another arrangement includes a substrate on which is formed both a 2D array of optical sensing elements, and a steganographic processor coupled to these elements to effect a steganographic operation. A variety of other novel technologies are also detailed.
摘要:
A mouse having X- and Y-position encoders, and associated circuitry for generating X- and Y-movement data, additionally includes an optical sensor for producing grey-scale image data, thereby allowing the mouse to serve both as a positioning device and an optical input device. Desirably, the substrate on which the optical sensor is formed also includes a steganographic decoder. This decoder can enable a variety of functionality, such as linking to web addresses steganographically encoded in print media (e.g., by subtle inking variations or by texture). In other embodiments, such a peripheral is provided without mouse-like functionality, and again permits reading machine-readable indicia printed in catalogs and the like.
摘要:
A number of novel watermarking applications, and improvements to watermarking methods, are disclosed. Included are techniques for encoding printed circuit boards and street signs with watermarks, deterring credit card fraud and controlling software licensing using watermarks, registering collectibles via watermarks, encoding the margins of printed pages with watermarks, and using watermarks to convey extra information in video by which fidelity of the rendered video may be improved. One particular arrangement is a method in which a PDA, wristwatch, or other portable device with a display screen presents a pattern that includes a machine-readable identifier. This image is sensed by a separate device, such as a webcam or a camera-equipped cell phone. The sensing device can then take an action based on the identifier. In some arrangements, the action is personalized to the user.