摘要:
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.
摘要:
A system for generating a security mark includes a data reception component that receives information. A security mark generation component in communication with the data reception component generates at least one security mark configuration based at least in part upon the received information. The at least one security mark configuration includes at least one simulation mark which resembles a natural feature. An application component applies one configuration of the at least one security mark configurations to a recipient. The applied security mark configuration obeys at least one rule whereby the security mark is distinguishable from the natural feature which it resembles by a system for detection of security marks.
摘要:
A method for enhancing color fidelity in multi-reproduction, includes scanning an image to be reproduced, wherein the image contains an invisible digital watermark including color information; decoding the color information contained in the watermark; comparing the decoded color information with the scanned image; generating a correction table from the differences between the decoded color information and the scanned image; and performing color correction on the scanned image using the correction table. This method confines the color error to one generation, even when copies go through multiple reproduction.
摘要:
Disclosed are systems and methods directed to digital watermarks, and more particularly, the generation of invisible correlation-based digital watermarks embedded in halftone images.
摘要:
Methods and systems used to automatically identify the marking process used for an image on a substrate based on spatial characteristics and/or color of the image. Image types which are classified and identified include continuous tone images and halftone images. Among halftone images separately identified are inkjet images, xerographic images and lithographic images. Locally adaptive image threshold techniques may be used to determine the spatial characteristics of the image.
摘要:
Methods and systems are presented for calibrating or characterizing a color printer or determining the color response of a color printer to combat spatial non-uniformity, in which color patches are printed on a test page according to an input matrix of input color in a printer-dependent-color space and the test page is measured to provide a corresponding output matrix of output color in a printer-independent-color space. Initial forward and inverse color transforms between the input and the output colors are generated based on the input and the output matrices. The output values are mapped to the input color space based on the initial inverse transform to form a feedback matrix, and spatial non-uniformities present in the printed test page are estimated according to noise values derived from the input matrix and the feedback matrix. The input matrix is modified according to the estimated spatial non-uniformity to form a modified input matrix of input color, and final forward and inverse transforms are generated for the color printer according to the modified input matrix and the output matrix.
摘要:
A method for generating an authenticable color image, the color image including a plurality of color separations, wherein an authentication image inserted in the multicolor image is not readily visually perceptible, includes halftoning image data corresponding to a first color separation using a single halftone screen, wherein the halftone screen includes means for generating an authentication image in a color image; and halftoning image data corresponding to a second color separation using the halftone screen and dot placement information for the image data corresponding to the first color separation to form a multicolor image; wherein halftoning of image data corresponding to the second color separation includes placing dots for the second color separation in thresholds of the halftone screen relative to those thresholds occupied by the first color separation in the halftone screen in accordance with a predetermined relationship.
摘要:
A system and method are disclosed for determining preferred image locations for placing watermark information (both hidden and obvious). The disclosure includes at least three criteria (image similarity, contrast, and image value range) that may be used alone or in combination to determine a preferred area of the target image for placing the watermark depending upon the user's intent for the mark (hiding or showing watermark).
摘要:
A stochastic dot-growth sequence for a stochastic screen can be initially compiled into two sections, including at least a first section and at least a section. Additional sections can be provided as necessary (e.g., third, fourth, etc.). The first section provides, for example, from 0% to 50% area coverage, while the section can provide an area coverage of between 50% and 100% depending upon design considerations. For the first section, the sequential values can be utilized to fill corresponding pixels of a “high addressability” stochastic screen. A similar process is then applied to the second section and additional sections, if necessary. In this manner, non-printable sub pixel issues can be avoided while providing improved color stability, smooth transitions, less noise and improved sharpness during rendering via a high addressability stochastic screen.
摘要:
The present invention is directed to an improved method for producing color watermarks in digitally reproducible color documents. The color watermarks are generated by producing a halftone pattern, which appears as stochastically distributed dots, in at least one or more color separations of the color document. A second halftone pattern, which also appears as stochastically distributed dots and is spatially displaced from the first halftone pattern, is generated in at least one or more different color separations. Portions of the first and second halftone patterns are auto-correlated or conjugally correlated, therefore, when the two halftone patterns are laid over each other, watermark patterns of highly contrasting colors become markedly visible.