The present invention provides an invisible-feature detection device capable of easily detecting a serial number with an invisible feature at low cost, a sheet recognition device, a sheet handling device, a print inspection device, and an invisible-feature detection method.

The application discloses apparatus and systems for authenticating physical object, identification documents and security documents. Some such methods and apparatus involve signal encoding or digital watermarking.

Various embodiments herein each include at least one of systems, methods, and software that assists in identification of a source of an unauthorized disclosure of a document, such as a public disclosure of check, receipt, or other document type. One method embodiment includes receiving a request for a stored document image from a requestor and retrieving the requested stored document image. This method may then apply a parameterized image deformation algorithm according to at least one input parameter to generate a watermarked image and then stores the at least one parameter and an identifier of the requestor in association with an identifier of the requested stored document in a watermarked image log. The watermarked image is then transmitted to the requestor.

The present disclosure relates generally to physical object authentication. In some embodiments, methods and apparatus relate to physical object authentication through comparison of randomly or pseudo-randomly occurring features with expected features. In some cases digital watermark or other indicia is used to convey the expected features. Of course, other combinations, embodiments and features are disclosed.

A method of printing a digital image includes printing authentication marks by applying an amplitude modulated raster print in a detection zone to an object, the printed area of the detection zone consisting of asymmetric raster dots, wherein at least two mutually non-parallel finder edges are printed from at least one finder zone to determine the position, boundary and orientation of the detection zone. A method of authenticating such a print includes capturing an image of the printed article; detecting the at least two finder edges to determine the detection zone from the image with halftone dot accuracy, comparing the captured print image of the detection zone with the resulting print images, and deciding on the basis of the comparison whether there is an original print on the article.

Various embodiments herein each include at least one of systems, methods, and software that assists in identification of a source of an unauthorized disclosure of a document, such as a public disclosure of check, receipt, or other document type. One method embodiment includes receiving a request for a stored document image from a requestor and retrieving the requested stored document image. This method may then apply a parameterized image deformation algorithm according to at least one input parameter to generate a watermarked image and then stores the at least one parameter and an identifier of the requestor in association with an identifier of the requested stored document in a watermarked image log. The watermarked image is then transmitted to the requestor.

The application discloses printed objects including encoded information, and methods, apparatus and systems for authenticating such printed objects. Some such objects, methods and apparatus involve data hiding and/or encoded signals.