摘要:
A method and system for identifying a fluorescence mark in a printed document includes using an image acquisition device to derive an input digital image that represents a printed document including a background and a fluorescence mark adjacent the background. The input digital image includes multiple color channel digital images, with each color channel digital image comprising a plurality of pixels each defined by a gray value. For each pixel of at least one of the color channel digital images, the gray value is adjusted based upon a variance of adjacent pixel gray values to define a filtered digital image including a plurality of pixels each defined by an adjusted gray value. Some pixels of the filtered digital image correspond to low variance regions of the input digital image and other pixels of the filtered digital image correspond to high variance regions of the input digital image. A binary image is derived that represents the filtered digital image by mapping each adjusted gray value of the filtered image to either a first or second possible binary pixel value. The binary image includes a binary representation of the fluorescence mark and a binary representation of the background. At least one morphological operation is performed on the binary image to adjust the pixel values of the binary representation of the background so that all pixel values of the binary representation of the background are opposite the binary pixel value used for the binary representation of the fluorescence mark. An ASCII character for the binary representation of the fluorescence mark (or each constituent character thereof) can be derived and compared to a known security code to authenticate the printed document.
摘要:
A method and apparatus to process digital images is described. The method is particularly effective in improving the appearance of digital images that originate in digital cameras and have been pre-processed in the camera.
摘要:
A method for encryption of a digital watermark by intelligent halftoning includes receiving image data that define at least a portion of a document to be printed in terms of at least three halftone images corresponding respectively to three printing colorants, each of the three halftone images comprising a plurality of halftone cells. The image data are modified by phase-shifting some of the halftone cells of at least one of the halftone images relative to the other halftone images to encode a watermark within the portion of the document such that the at least one phase-shifted halftone image includes a phase-shifted region and a non-phase-shifted region. The modified image data are used to print the portion of the document on a substrate that will fluoresce when subjected to UV illumination. The printed portion of the document includes a first printed pattern resulting from the phase-shifted region and a second printed pattern resulting from the non-phase-shifted region. The first and second patterns of the printed portion of the document appear substantially similar when the portion of the document is viewed in visible light, and appear dissimilar when the portion of the document is viewed in UV light such that the watermark encoded in the modified image data is perceptible when the portion of the document is viewed in UV light and is hidden when the portion of the document is viewed in visible light.
摘要:
Systems and methods provide data processing before data compression. The data processing includes contrast enhancement and/or custom color mapping.
摘要:
A method and system is provided for generating a variable data differential line pattern font comprising forming a periodic line pattern suitable for tessellation disposition within a printed document and selectively distorting a portion of the periodic line pattern in a predetermined manner wherein the distorting comprises generating a distinguishable font corresponding to the distorting. A plurality of different distinguishable fonts are formed by a corresponding plurality of distorted line patterns, respectively.
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:
A method of adjusting a TRC of an image is provided. The method involves receiving an image at an input resolution, resampling the image to a processing resolution if the imput resolution and the processing resolution are not same, processing the image using rank-ordered error diffusion, and resampling the processed image to a desired output resolution for the image if the processing resolution and the output resolution are not same.
摘要:
A method for run-time streak removal from a scanned image includes providing a scan line of image data from the scanned image; detecting corrupted data within the scan line; evaluating image data located in a neighborhood before and after the corrupted data on the scan line; if the evaluated image data in the neighborhood is smooth, replacing the corrupted data with image data determined by a linear interpolation process; and else if the evaluated image data in the neighborhood is not smooth, replacing the corrupted data with image data determined by the linear prediction process. Various techniques can be used to evaluate the image data located in the surrounding neighborhood. For example, a filter selection step may be used based on prediction discrepancies.
摘要:
A method is provided for creation of a substrate fluorescence mask having background color(s), UV mark color(s), and distraction color(s), to be printed as an image on a substrate containing optical brightening agents. The method includes selecting one or more UV mark colors for the mask such that the UV mark colors exhibit low contrast against the background color(s) under normal illumination and high contrast against the background color(s) under UV illumination. One or more distraction colors are also selected, such that the distraction color(s) exhibit low contrast against the background color(s) under UV illumination and exhibit high contrast against the background color(s) under normal illumination. A distraction pattern, formed from one or more distraction colors, is also selected.
摘要:
The present disclosure relates to providing a user interface for the effective generation of differential gloss images. The user is instructed to indicate the base primary image data, and the desired gloss image data. This data may be displayed for verification and position adjustment by superimposition of the gloss image data upon the base image data. In an alternative, the placement information may be inferred from the position of originals upon the scanner or copier platen and the result may or may not be displayed. By selectively applying halftones with different anisotropic structure orientation characteristics to the base primary image data as directed by the desired gloss image data, a differential gloss image file or hardcopy may be provided.