Some implementations may include a method for watermarking an identification document, the method including: modulating a spatial luminance pattern associated with a first digital watermark to encode a first portion of personally identifiable information; modulating a spatial chrominance distribution associated with a second digital watermark to encode a second portion of the personally identifiable information; and applying the first digital watermark and the second digital watermark to the identification document.

Artwork carrying machine readable data is generated by editing artwork according to a data signal or transforming the data signal into artwork. The machine-readable data signal is generated from a digital payload and converted into an image tile. Artwork is edited according to the image tile by moving graphic elements, adapting intersections of lines, or altering line density, among other techniques. Artwork is generated from the data signal by skeletonizing it and applying morphological operators to a skeletal representation, such as a medial axis transform. Artistic effects are introduced by filtering the data signal with directional blurring or shape filters.

Some implementations may include a computer-assisted method for authenticating a person at a point of service, the method including: receiving a digital identification document including a digital biometric of the person and a digital watermark, the digital watermark encoding personally identifiable information of the person; retrieving the digital watermark from the received digital identification document; extracting the personally identifiable information from the retrieved digital watermark; and authenticating the person identified by the digital biometric based on the retrieved digital watermark.

A thin high strength steel sheet having excellent formability has a composition which includes, by mass %, 0.08 to 0.15% of C, 0.5 to 1.5% of Si, 0.5 to 1.5% of Mn, 0.01 to 0.1% of Al, and 0.005% or less of N.

Some implementations may include a method for watermarking an identification document, the method including: modulating a spatial luminance pattern associated with a first digital watermark to encode a first portion of personally identifiable information; modulating a spatial chrominance distribution associated with a second digital watermark to encode a second portion of the personally identifiable information; and applying the first digital watermark and the second digital watermark to the identification document.

In one embodiment, a command is received from a video provider at a media rendering device, the command being a command to embed a subscriber ID in at least one video frame in a video stream. A random key, k is also received from the video provider at the media rendering device. An injective transformation is invoked for k and the subscriber ID, the injective transformation generating a sequence of pairs of: near-transparent patterns and corresponding time periods. Logical blocks of the at least one video frame in the video stream are overlaid with one of the near-transparent patterns for its one of the corresponding time periods. Related apparatus, systems, and methods are also described.

Certainty of detecting a watermark embedded in a color image is increased. Image data acquisition means of an image processing device acquires image data. Histogram generation means generates, based on pixel values of an image indicated by the image data acquired by the image data acquisition means, a histogram for each region in the image. Region selection means selects tom the image a region having a sparse color distribution in the histogram generated by the histogram generation means. Image processing means embeds a watermark in the region selected by the region selection means.

Some implementations may include a computer-implemented method for applying at least two digital watermarks to a digital document, the method including: receiving a digital document comprising visual contents; generating a first digital watermark to be visually presented at a first time point; generating a second digital watermark to be visually presented at a second time point, the second digital watermark being different from the first digital watermark and the second time point being different from the first time point; and applying both the first digital watermark and second digital watermark to the digital document t.

Certainty of detecting watermarks embedded in a color image is increased. Image date acquisition means of an image processing device acquires image data on a color image having a plurality of color channels. Numerical value acquisition means acquires respective numerical values in the plurality of color channels contained in a pixel value of the color image based on the image data acquired by the image data acquisition means. Image processing means embed a watermark in each of the plurality of color channels by changing the numerical value acquired by the numerical value acquisition means.

Example systems disclosed herein to detect watermark modifications include a watermark encoder to encode a second watermark in a sampled media signal obtained from a received broadcast signal, the sampled media signal already encoded with a first watermark that was included in the received broadcast signal. Disclosed example systems also include a watermark decoder to detect the first watermark and the second watermark in the sampled media signal, and a watermark modification evaluator to compare a first metric determined for the first watermark and a second metric determined for the second watermark to determine whether the first watermark was modified prior to being included in the received broadcast signal. Disclosed example systems further include a ratings server to revise ratings data corresponding to the received broadcast signal when the first watermark is determined to have been modified prior to being included in the received broadcast signal.