Abstract: Provided are methods, apparatus and systems related to watermark encoding via pixel spacing modulation. According to one exemplary embodiment, a method modulates the pixel spacing associated with an image to encode a watermark.

Abstract: A system is adapted for simulating a textured pattern on a non-textured substrate. The system includes generating at least a first textured description in a controller unit operatively associated with at least one image forming apparatus. The first textured description is combined with at least one image of an original print job to generate a first print job. The first textured description is printed on at least one face of a substrate to provide a perceived first textured substrate. The at least one image is then printed on the perceived first textured substrate.

Abstract: Disclosed are methods and apparatus for reproducing an image using one or more halftone screens for one or more respective colorants in the methods and apparatus reducing the beating of one or more excitation frequencies with one or more harmonic frequencies associated with the halftone screens. According to an exemplary method, one or more halftone screens are selected such that the fundamental frequency of an excitation frequency coincides with a harmonic frequency of a halftone screen.

Abstract: A method includes receiving a primary image as input data and receiving textured image data for rendering a perceived non-uniform texture on a printed output of the primary image. The primary image input data is used for determining a low coverage portion and a high coverage portion. The method then includes applying clear toner to the low coverage portion and applying colored toner at variable anisotropic orientations to the high coverage portion.

Abstract: As set forth herein, computer-implemented methods and systems facilitate the generation of halftone screens for moiré-free color halftoning. A first fundamental frequency vector and a second fundamental frequency vector of a halftone cell are sheared using a selected shearing value. The shearing value is selected as an offset in a fast scanning or slow scanning direction. The selected shearing value satisfies various moiré-free conditions associated with the identified frequency vectors and is capable of being selected for multiple halftone screens. The halftone screens generated using the sheared frequency vectors are used for moiré-free halftoning.

Abstract: Disclosed are moiré-free color halftoning methods, apparatus and systems to digitally reproduce an original color image. The disclosed embodiments are particularly useful for rendering a color image with a color printing device. According to one exemplary embodiment, an image forming method utilizes three or four rotated hexagonal screens which can include regular shaped hexagon screens or convex tessellated hexagon screens.

Abstract: Disclosed are methods/systems to embed a watermark into a contone image. Specifically, the disclosed methods and systems spatially modulate a contone image substantially adjacent a watermark area according to a first polarization and spatially modulate the contone image substantially within the watermark area according to a second polarization. These spatially modulated images may then be subsequently processed, stored, communicated and/or rendered.

Abstract: A method and apparatus are provided for compensating for spatial non-uniformities in a printer by deriving a true spatial non-uniformity tone response curve (TRC) that characterizes the printer in terms of color output variation for each addressable pixel location in a spatial range. The “true average” tone response curve is determined for a color channel. A prediction of the true response as a function of the spatial location is derived by printing and scanning a specially designed halftone-independent target of binary patterns. The predicted tone response curve for each color channel and halftone is predicted using a binary printer model, wherein the “predicted tone response curve” provides a model based approximation of the actual response for each addressable pixel location in the spatial range. Also stored is an “average predicted tone response” by averaging the “predicted tone response curve” over the spatial range of the printer.

Abstract: As set forth herein, computer-implemented methods and systems facilitate halftoning by adapting 2nd generation halftone techniques to the spatial frequency content of an image utilizing a spot function introduced in conjunction with a technique for determining seed locations, which results in halftone images exhibiting improved edge and detail rendition. A dominant orientation of pixels in an input image is employed to select a pre-generated stochastic screen used to determine the seed locations.

Abstract: A model-based halftone independent method for characterizing a printer equipped with a plural of halftone screens comprises: printing a target set of basic patches comprised of a fundamental binary pattern independent of a halftone screen; measuring true color printer response from the target set; modeling a halftone independent characterization of the printer with the mathematical transformation using the measured response; modeling a first halftone dependent characterization of the printer with the mathematical transformer to generate a first predicted result using a selected halftone screen; comparing a measured response of the printer using the halftone screen with the predicted result to define a correction factor corresponding to the halftone screen; and modeling a halftone dependent characterization of the printer using a predicted response of the fundamental binary pattern and the correction factor.

Abstract: A method for defining a gloss effect in a printed document includes printing a document region with first and second colorant combinations. The first colorant combination defines a first colorant stack height and said second colorant combination defines a second colorant stack height that differs from the first colorant stack height. As such, the document region has a first appearance when viewed straight-on and a second appearance when viewed at an angle. In one example, the first colorant combination is black (K) colorant that results in a one-level stack height and the second colorant combination is cyan, magenta, and yellow (CMY) colorants that result in a three-level stack height. In another example, the second colorant combination can be cyan, magenta, yellow and black (CMYK) colorants that define a four-level stack height.

Abstract: As set forth herein, computer-implemented methods and systems facilitate halftoning using boundaries and centers of a polygonal tiling with a parameterized spot function that operates within the tiles. Defining the halftone structure includes defining the polygonal tiling with a specification of the polygon boundaries and center, and setting and applying parameters of the spot function, which utilizes center-to-boundary distances. The tiling can be defined explicitly, by defining a tile structure, or providing centers, one per polygon, and vertices for the polygons. The vertices and centers are used to generate the polygon boundaries. The polygonal tiling can be regular (e.g., repetitive) or irregular, and can also be varied in a manner adapted to the image content or to data that is being embedded.

Abstract: As set forth herein, computer-implemented methods and systems facilitate halftoning using a parametrically controlled spot function based on triangle tessellation, which in turn facilitates dot growth control of periodic halftone using an irregular seed structure. The spot function determines the shape of the halftone dot used to reproduce a given pixel. The spot function is well suited for growing halftone dots arrayed on a non-regular grid and can also be used for grids with regular order. The spot function includes adjustable parameters for controlling its sharpness and slope.

Abstract: Described herein is a level I (overt) feature for security printing intended to deter unauthorized modification of text documents. The exemplary method includes generating a textured background that follows the contour of the text it surrounds and is difficult to modify. The background patterns may be generated with a two-step procedure that first creates a smooth function and then modulates it to produce patterns with sharp contrast. Tampering will be deterred as visible artifacts will be created when text is altered. Compared to the levels II and III features, the exemplary method relies on human vision for detection and does not require any special tools and instruments. It can be used in applications where fast, simple and inexpensive inspection is essential, or combined with other technologies for enhancing overall effectiveness.

Abstract: Systems and methods are described for halftone independent temporal color drift correction, particularly for correction in hi-addressability xerographic printers. For example, a method includes printing target patches, including two resolutions, measuring printer response from the target patches, and modeling the printer using a transformation to define a correction factor, and a predicted response.

Abstract: A toner set includes a plurality of toners, at least one toner but less than all toners of the toner set including binder, colorant and fluorescence agent and remaining additional toners including binder, colorant and free of fluorescence agent. At least a first toner grouping and a second toner grouping of the toner set form a combination, the first and second groupings of the combination exhibiting a substantially same color under ambient light conditions upon image formation. The first toner grouping and the second toner grouping of the combination contain a different amount of the fluorescence agent, wherein upon exposure to activating energy, the fluorescence agent fluoresces to cause a visible change in the color of a pattern formed in an image by the first toner grouping as compared to the second toner grouping.

Abstract: A system reveals a 2D barcode in a document. A 2D barcode generator selects the placement and at least one colorant combination of an image and at least one colorant combination for a 2D barcode on a document, where the at least one colorant combination of the image and the 2D barcode form a metameric pair. A print system receives data from the 2D barcode generator and places the image and the 2D barcode on the document. A light source selected or tuned to a wavelength corresponding to the colorant combinations utilized by the print system reveals the 2D barcode placed thereon. A decoding element decodes and extracts data from the revealed 2D barcode.

Abstract: A toner set includes a plurality of toners, at least one toner but less than all toners of the toner set including binder, colorant and fluorescence agent and remaining additional toners including binder, colorant and free of fluorescence agent. At least a first toner grouping and a second toner grouping of the toner set form a combination, the first and second groupings of the combination exhibiting a substantially same color under ambient light conditions upon image formation. The first toner grouping and the second toner grouping of the combination contain a different amount of the fluorescence agent, wherein upon exposure to activating energy, the fluorescence agent fluoresces to cause a visible change in the color of a pattern formed in an image by the first toner grouping as compared to the second toner grouping.

Abstract: A method for simulating a textured appearance on a uniform substrate includes using variable halftone dot orientations. A texture description is provided for generating electronic data representing a three-dimensional texture. Texture regions of the texture description are identified using pixel cells in the electronic data. Halftone dot orientations are assigned for each pixel cell based on a value of the pixel cell. The halftone dot orientation represents a recessed or a raised surface portion.

Abstract: A method for creating a differential gloss image includes providing first and second anisotropic halftone structures. The first and second anisotropic structures have different orientations. One of the first and second anisotropic structures is applied to image data in a first region of an image to be halftoned. The other of the first and second anisotropic structures may be applied to image data in a second region of an image to be halftoned. A mixture of the first and second anisotropic structures is applied to image data in a third region of the image to be halftoned, whereby when printed, the three regions each have a gloss characteristic which differs from that of the other two regions.