A method and system for hiding reversible data based on prediction errors are provided, where the method includes: partitioning an image, to obtain a shadow part and a blank part; performing a first-layer embedding process on the shadow part; performing a multi-layer embedding process on the blank part; extracting outermost layer information of the blank part after the multilayer embedding process; and extracting information of the shadow part after the first-layer embedding process. According to the method in the present disclosure, a problem of image distortion during high-capacity data embedding can be effectively solved.

Example implementations relate to multiple payload pantograph. Some examples may include a first pattern generation engine to generate a first pattern. The first pattern may be a data-bearing pattern encoding a first payload. Additionally, some examples may include a second pattern generation engine to generate a second pattern, the second pattern (by itself or in combination with the first pattern) may represent a second payload. The second payload may be camouflaged by a combination of the first pattern and the second pattern. Some examples may also include a pantograph generation engine to generate a multiple payload pantograph including the first pattern and the second pattern. The multiple payload pantograph may include the first pattern in one of the pantograph background or the pantograph foreground.

An image processing apparatus includes: a first obtaining unit configured to obtain an original image; a second obtaining unit configured to obtain region information indicating first and second regions, the first region read in reading of a print original to have a higher density than the second region, the second region read in the reading to have a lower density than the first region; an embedding unit configured to embed information in the original image by embedding a pattern with a directivity in the first region and embed, in the second region, a pattern in which the number of pixels printed adjacent to printed pixels is smaller than that in the first region; and a control unit configured to perform control of outputting the print original by using a print image in which the patterns of the first and second regions are embedded by the embedding unit.

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.

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.

Some implementations may provide a computer-implemented method for validating a digital document, the method including: receiving, at a computing device, the digital document comprising at least two digital watermarks, the digital document issued by a central entity; retrieving a first digital watermark from the digital document, the first digital watermark visually presented at a first time point; retrieving a second digital watermark from the digital document, the second digital watermark 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 reading the digital document based on the retrieved first and second digital watermarks.

A method and system for hiding reversible data based on prediction errors are provided, where the method includes: partitioning an image, to obtain a shadow part and a blank part; performing a first-layer embedding process on the shadow part; performing a multi-layer embedding process on the blank part; extracting outermost layer information of the blank part after the multilayer embedding process; and extracting information of the shadow part after the first-layer embedding process. According to the method in the present disclosure, a problem of image distortion during high-capacity data embedding can be effectively solved.

Example implementations relate to multiple payload pantograph. Some examples may include a first pattern generation engine to generate a first pattern. The first pattern may be a data-bearing pattern encoding a first payload. Additionally, some examples may include a second pattern generation engine to generate a second pattern, the second pattern (by itself or in combination with the first pattern) may represent a second payload. The second payload may be camouflaged by a combination of the first pattern and the second pattern. Some examples may also include a pantograph generation engine to generate a multiple payload pantograph including the first pattern and the second pattern. The multiple payload pantograph may include the first pattern in one of the pantograph background or the pantograph foreground.

This disclosure describes novel methods for generating unique copies of content. One method combines the functions of the master copy and unique copy watermarks. In particular, the method generates a unique copy by varying the manner in which the master copy watermark is embedded in unique copies of a content item. In one embodiment, the master copy watermark is repeated within the content item and its location is varied in a unique pattern that comprises the unique copy watermark. The unique copy is generated by producing a copy in which master copy watermarks are embedded in a unique pattern. For instance in one embodiment, the locations of the master copy watermarks in the content item are represented as a vector of delta values in which each delta value corresponds to the distance between a corresponding instance of the master copy watermark, and a neighboring instance of the master copy watermark. This vector is stored in a transaction record in association with transaction information, such as information identifying the master copy and information associated with the unique copy. Other ways of representing the unique pattern of attributes of the master copy watermark are also possible. In other embodiments, properties of the master copy watermark other than its location are varied through the content. The unique copy watermark is conveyed in the vector of deltas in these properties of the master copy watermark. Some examples of these properties of the master copy watermark signal include phase characteristics (e.g., the phase shift of a watermark carrier signal), frequency magnitude characteristics, etc. These properties are varied in a manner that does not alter the information carried in the master copy watermark. However, it does provide a variation that creates a unique copy, and the unique copy watermark is conveyed in this variation. The variation in location of the instances of the master copy watermark can be in different domains, such as a spatial domain, a time domain, a time-space domain, a transform domain (including frequency transform domains), a compressed domain, etc.

Related are a method and system for embedding information into encoding information. The method comprises the steps of first embedding the information into an embeddable image or a virtual image using a frequency domain embedding method, and then overlaying the embeddable image or the virtual image into a printed file in need of a variable code or a fixed code using a spatial domain processing method. In this way, the information not perceived by human eyes may be embedded into the encoding information using frequency domain and spatial domain transformation, the counterfeiting difficultly is extremely large, the cost is high, and the anti-counterfeiting purpose is achieved; and furthermore, the printing cost is not increased, thereby being beneficial to wide promotion and application.