A color chart is for evaluating printing quality of an image forming apparatus. The color chart includes identification information and a color evaluation patch. The identification information is on an image forming apparatus on which evaluation of printing quality is to be performed. The color evaluation patch includes a plurality of color patches for performing evaluation of printing quality on the image forming apparatus indicated by the identification information.

In an example method, a first dot pattern of shadow dots and second dot pattern of highlight dots is generated. The first dot pattern and second dot pattern include information to be encoded across the image. The first dot pattern and the second dot pattern are mapped to a corresponding subset of the greyscale source pixels, the greyscale source pixels corresponding to an image to be printed. A value of a greyscale pixel in the subset of the greyscale source pixels is modified based on a predetermined threshold pixel value. The value of the greyscale pixel is set to a highlight dot value in response to detecting that the predetermined threshold pixel value is exceeded or set to a shadow dot value in response to detecting that the predetermined threshold value is not exceeded. The image including the subset of pixels with modified values is printed.

The present disclosure relates generally to signal encoding for elements within PDF files. One implementation encodes an artwork element under different encoding conditions, and selects a winner version based on resulting signal robustness and/or visibility. Other implementations generate PDF layer masks to help determine overall embedding robustness, including interference from layered elements. Other implementations are provided too.

The subject matter discloses examples of an identification marking system comprising a component analyzer to identify a plurality of components present within a print artwork. The identification marking system further comprises a marking technique analyzer to determine marking settings for the plurality of components based on component properties and predefined marking rules. The marking settings for a component indicates a marking technique identified for linking an identification mark with the component. The marking technique analyzer is further to communicate the print artwork and the marking settings to an identification marking engine for identification marking.

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.

An image processing system for verifying that embedded digital content satisfies a predetermined criterion associated with display of the content, the image processing system a content embedding engine that embeds content in a resource provided by a content provider and that configures the resource for rendering, a rendering engine that renders the content embedded in the resource; an application interface engine that interfaces with the rendering engine and that generates a visualization of the resource and of the embedded content rendered in the resource; and an image processing engine that processes one or more pixels of the generated visualization of the resource and of the embedded content and the resource to verify that the specified visual element satisfies the predetermined criterion; and transmits verification data comprising an indication of whether the predetermined criterion is satisfied.

An image processing system for verifying that embedded digital content satisfies a predetermined criterion associated with display of the content, the image processing system a content embedding engine that embeds content in a resource provided by a content provider and that configures the resource for rendering, a rendering engine that renders the content embedded in the resource; an application interface engine that interfaces with the rendering engine and that generates a visualization of the resource and of the embedded content rendered in the resource; and an image processing engine that processes one or more pixels of the generated visualization of the resource and of the embedded content and the resource to verify that the specified visual element satisfies the predetermined criterion; and transmits verification data comprising an indication of whether the predetermined criterion is satisfied.

A digital watermark analysis apparatus, comprising an image capturing unit for capturing a printed product where additional information is embedded by superimposing a pattern on an image to acquire a captured image, a calculation unit for calculating a spatial frequency characteristic of each small area in the captured image, a specifying unit for specifying an embedded signal strength and an embedding position of the additional information, a decision unit for deciding, based on the embedding position information and the embedded signal strength information, a position in the captured image of a marker detection area for detecting a marker as a reference position for acquiring the additional information, and an acquisition unit for detecting a marker in the marker detection area and acquiring the additional information in the captured image with reference to the detected marker.

A method may include obtaining a first byte stream from first document code and a second byte stream from second document code. The first document code has a document type and the second document code has the document type. The method may further include identifying, in the first byte stream, nonvisual noise corresponding to a custom byte code defined in a custom character encoding set. The nonvisual noise is invisible when rendering the first document code. The method may further include replacing, in the first byte stream, the custom byte code with at least one standard byte code defined in a standard character encoding set to obtain modified document code. The second document code uses the standard character encoding set. The method may further include comparing the modified document code with the second document code by comparing the first byte stream with the second byte stream.

A method for providing watermark to subscribers is provided. The method comprises observing a request for a first content from a subscriber, determining if the subscriber can receive a watermark, generating a second content comprising the watermark if the subscriber can receive a watermark, causing the subscriber to fetch the first content, and causing the subscriber to fetch the second content comprising the watermark overlaying the first content.