A method for transforming an input array of pixel data into an output array of data, to yield enhanced expression of a digital watermark signal in the output array. One such method includes, for each pixel in the input array, generating a first datum that indicates a value difference between said pixel and a neighboring pixel in a first direction, the first data thereby collectively comprising a first directional difference array. Similarly, for each such pixel in the input array, generating a second datum that indicates a value difference between said pixel and a neighboring pixel in a second direction, the second data thereby collectively comprising a second directional difference array. One or more transforms to a spatial frequency domain are then performed, using these first and second directional difference arrays as input data. First and second results from the one or more transformations are then combined to yield an output array. The just detailed process causes the digital watermark signal in the output array to exhibit a greater signal-to-noise ratio than in the digital watermark signal in the input array. A great number of other features and arrangements are also detailed.

A method for transforming an input array of pixel data into an output array of data, to yield enhanced expression of a digital watermark signal in the output array. One such method includes, for each pixel in the input array, generating a first datum that indicates a value difference between said pixel and a neighboring pixel in a first direction, the first data thereby collectively comprising a first directional difference array. Similarly, for each such pixel in the input array, generating a second datum that indicates a value difference between said pixel and a neighboring pixel in a second direction, the second data thereby collectively comprising a second directional difference array. One or more transforms to a spatial frequency domain are then performed, using these first and second directional difference arrays as input data. First and second results from the one or more transformations are then combined to yield an output array. The just detailed process causes the digital watermark signal in the output array to exhibit a greater signal-to-noise ratio than in the digital watermark signal in the input array. A great number of other features and arrangements are also detailed.

This disclosure relates to advanced signal processing technology including steganographic embedding and digital watermarking. One combination includes an image processing method comprising: obtaining data representing a digital image; using one or more processors, embedding an information signal within the data representing a digital image, the information signal comprising a synchronization component and a message component, said embedding yielding altered data; transforming the altered data to estimate a print and optical capture process, said transforming yielding transformed, altered data; for each of a plurality of regions within the transformed, altered data, generating detectability measures, in which a first detectability measure comprises a measure corresponding to synchronization component strength within region of the transformed, altered data, and in which a second measure comprises a measure corresponding to message component strength within the region of the transformed, altered data; based on a combination of the detectability measures from each of the plurality of regions, determining a likelihood that the altered data, once printed on a physical substrate, will be detectable from optical scan data representing such. Of course, other features and combinations are described as well.

Methods and devices are provided to identify live broadcast content that are multiple identities. One method includes is based on-the-fly modification of the broadcast content during broadcast and includes receiving the content that already includes pre-existing identification information that is embedded in the content, embedding a number of additional watermarks into the content as the content is being transmitted for live broadcast, where the plurality of additional watermarks includes a new identification information for the content. Just at the embedding of the additional watermark is commented, the pre-existing identification information, the new identification information and a temporal relationship between the pre-existing and additional watermarks are transmitted to a remote database, which can be used to enable reception of information based on the pre-existing identification.

Digital watermarking is adapted for the variable data printing. A reference signal serves as a proxy for optimizing the embedding a watermark in a host image to be printed. Using the reference signal, embedding parameters are generated, which are a function of constraints such as visual quality and robustness of the machine readable data. Adjustments needed to embed a unique payload in each printed piece are generated using the embedding parameters. These adjustments are stored in a manner that enables them to be efficiently obtained and applied within the raster image processor or press during operation of the press. Various other methods, system configurations and applications are also detailed.

A method for transforming an input array of pixel data into an output array of data, to yield enhanced expression of a digital watermark signal in the output array. One such method includes, for each pixel in the input array, generating a first datum that indicates a value difference between said pixel and a neighboring pixel in a first direction, the first data thereby collectively comprising a first directional difference array. Similarly, for each such pixel in the input array, generating a second datum that indicates a value difference between said pixel and a neighboring pixel in a second direction, the second data thereby collectively comprising a second directional difference array. One or more transforms to a spatial frequency domain are then performed, using these first and second directional difference arrays as input data. First and second results from the one or more transformations are then combined to yield an output array. The just detailed process causes the digital watermark signal in the output array to exhibit a greater signal-to-noise ratio than in the digital watermark signal in the input array. A great number of other features and arrangements are also detailed.

Variable data printing workflows are enhanced for use with content that includes 2D code patterns, such as digital watermark data. One arrangement includes applying a filter to a content stream within a PDF document to extract both first variable pattern data for a first watermark pattern and second variable pattern data for a second watermark pattern. A first composite watermark pattern is then defined based on the extracted first variable watermark pattern data in conjunction with static watermark pattern data, and a second composite watermark pattern is defined based on the extracted second variable watermark pattern data in conjunction with the static watermark pattern data. A variety of other features and arrangements are also detailed.

A steganographic digital watermark signal is decoded from host imagery without requiring a domain transformation for signal synchronization, thereby speeding and simplifying the decoding operation. In time-limited applications, such as in supermarket point-of-sale scanners that attempt watermark decode operations on dozens of video frames every second, the speed improvement allows a greater percentage of each image frame to be analyzed for watermark data. In battery-powered mobile devices, avoidance of repeated domain transformations extends battery life. A great variety of other features and arrangements, including machine learning aspects, are also detailed.

In one aspect, assembly of multi-part food packaging is checked by reference to payloads of steganographically-encoded digital watermarks printed across the packaging components. Marking all surfaces of the packaging components allows arbitrary orientation of feed stock in assembly equipment, and wide latitude in placement of inspection cameras along the packaging line. In another aspect, a scanner at a retail checkout station is alert to any gap detected in steganographic encoding on retail product packaging and, if found, alerts an operator to possible presence of an adhesive label with a misleading barcode. A great variety of others features and arrangements are also detailed.

The present disclosure provides a method of embedding a watermark on a Joint Photographic Experts Group (JPEG) image. The method includes: performing an entropy decoding on the JPEG image to generate quantized discrete cosine transform (DCT) coefficients; determining target bits in a bit plane of the quantized DCT coefficients on the basis of a watermark-embedding table (WET); and embedding a watermark based on metadata of the JPEG image in the target bits. Also, the present disclosure provides a method of verifying integrity of the image by using the embedded watermark.