Xerox Corporation

Ying-wei Lin

Robert P Loce

Zhigang Fan

John C Handley

Hui Ting Cheng

Anthony F Calarco

Jeng-nan Shiau

Leon C Williams

Michael Branciforte

Ronald E Jodoin

Raja Bala

Shen-Ge Wang

Stuart Alan Schweid

Beilei Xu

R Victor Klassen

Martin Edward Banton

Katherine Loj

Raphael F Bov, Jr

Salil Prabhakar

Hong Li

Chu-Heng Liu

Bing R Hsieh

Jagdish C Tandon

William A Fuss

Michael S Cianciosi

Lisa M Yamonaco

Paul D Norder

Thomas A Sanderson

A method for determining local defocus distance in a scanned image of a non-planar original object is provided comprising scanning at least a portion of the non-planar original object to produce first scanned image data at a first focal plane and scanning same the at least a portion of the non-planar original object to produce at least second scanned image data at a second focal plane. The first scanned image data is different from the second scanned image data wherein a distance between the first focal plane and the second focal plane is a predetermined quantity. The method further comprises estimating an out-of-focus distance of the object from the first and the second scanned image data.

Method for estimation of image defocus and defocus restoration

The present disclosure is directed to a method and apparatus for applying magnetic ink character recognition (MICR) technology to enable the embedding of coded information within text characters of a document.

Magnetic watermark for text documents

A system and method for classifying an image block of a printed image into contone, halftone, or error diffusion classes, includes scanning the printed image; selecting an n by n block of pixels from the scanned image in a luminance channel; calculating an array of DCT coefficients of the pixel block, wherein the calculated DCT coefficients are representative of spatial frequency and spatial orientation of the pixel block; comparing the array of DCT coefficients with an array of predetermined values, wherein the array of predetermined values are indicative of contone, halftone and error diffusion classes; and determining the image classification of the pixel block based on the comparison of the DCT coefficients with the array of predetermined values. If the image is determined to be halftone, then the method further evaluates the DCT coefficients to determine the frequency of the halftone screen.

Method and system for image classification and halftone frequency detection

The present invention is a method and apparatus for applying magnetic ink character recognition (MICR) technology to enable the embedding of coded information within text characters of a document.

A method to detect frequency and angle of a binary halftone pattern. The method employs an exclusive-or operation which is applied locally to a region of a binary bit map and its spatially shifted version. The resulting bits from the exclusive-or operation are summed over the region. The exclusive-or operation is repeated for a range of shift values. In a halftone region, the shift at which the minimum sum occurs reflects the angle and the frequency of the halftone.

Binary halftone detection

Systems and methods are presented for processing and rendering image data during a single pass through the image data. A method includes loading scanlines of image data into a rolling band buffer, performing a windowing technique on the image data, and determining if a class change was experienced by any window having a portion in an output scanline of the buffer. The method further includes processing image data in the output scanline for a window portion that experienced a class change, using a blended rendering algorithm. If no class change is detected, the method includes processing image data in the output scanline for the window portion using a class-based rendering algorithm. The method optionally includes rendering processed image data for the output scanline to a rendering device. According to other features, an apparatus includes a rolling band buffer, a windowing processor, class-based rendering algorithms, and a blended rendering algorithm.

Method and apparatus for windowing and image rendition

A process for color graphics image processing, related to detection and segmentation of sweeps, is provided. An input graphics image is transformed into a three-dimensional histogram in an appropriate color space(e.g., CIELUV). Two-dimensional histograms are estimated from the three-dimensional histogramThe two-dimensional histograms are processed to detect and segment sweepsSweep segment information from the processing of the two-dimensional histograms is combinedThe combined sweep segment information is used to process the input graphics image to identify and segment sweepsPost-processing may be optionally and selectively used to reject false alarms (i.e., areas falsely identified as sweeps)

Detection and segmentation of sweeps in color graphics images

A method for neutral pixel detection using color space feature vectors wherein one color space coordinate represents lightness is provided. The method includes the following steps: a) receiving an input image represented in a first color space; b) converting the input image to a second color space wherein one coordinate represents lightness; c) selecting a pixel in the second color space representation to be classified; d) computing second color space feature vectors associated with the selected pixel; and e) classifying the selected pixel between neutral and color classes based on the values computed for the second color space feature vectors. Typically, the input image is processed using a smoothing filter to create a smoothed input image prior to the conversion to the second color space. The method can be adapted to page processing or strip processing schemes with respect to the input image.

Neutral pixel detection using color space feature vectors wherein one color space coordinate represents lightness

A platen cover for an imaging device such as a copier or scanner includes a substrate and at least of portion of the surface of the substrate is coated with a fluorescent coating. Preferably, the substrate has a dark or black color. The dark color of the substrate substantially reduces or eliminates show through of an image on the backside of an original document when the platen cover is not exposed to a light source for imaging. At the same time, when holes or uneven borders are present in the original document, the fluorescent coating fluoresces upon exposure to the light source at these regions of the original document, making these portions appear white in the replicated image and thereby substantially reducing or eliminating the unsightly appearance of these portions as black portions in the replicated image.

Copier or scanner platen cover with fluorescent coating

An annular window-shaped structuring element is provided for image processing to remove speckles from a scanned image. The window-shaped structuring element is composed of two differently sized squares sharing the same geometric center-point. The pixel to be analyzed with the structuring element is at the center-point. The structuring element is used in a method to remove speckles from binary, grayscale, and/or color images by first eroding the image, detecting speckles relative to other pixels in the image, and removing declared speckles. The method may additionally include a halftoning module to protect halftone images.

Grayscale image de-speckle algorithm

A continuously variable screening tool is used to generate a unique texture pattern for every color in a multicolor image. The continuously variable screening tool allows a single colorant version of the image to be generated with less information loss than typically suffered in the multicolor to single color transformation process. The continuously variable screening tool is generated by blending patterns from a set of reference screens. The reference screens are associated with selected reference colors in, for example, a machine independent color space. A calculated screen is generated through a weighted blend of reference screens located near the arbitrary color in the machine independent color space. Typically, the weights depend on the distance the arbitrary color is from each of the reference colors. The screens consist of arrays of threshold values. Each threshold value is associated with a dot position and an image pixel. Where a pixel value exceeds the associated threshold value, provision is made to place a mark in the associated dot position. An image processor operative to carry out the method comprises a continuously variable screening tool generator. An embodiment of the image processor includes a reference screen storage device and a screen blender.

Color to black and white converter

A watermarked image generator includes a watermark data source that inputs watermark data to a watermark embedding device. The watermark embedding device halftones the input image to generate the output image made of 2&#xd7;2 binary patterns, the 2&#xd7;2 binary patterns forming the watermarks embedded in the output image. The watermark embedding device includes a tri-level error diffusion generator that performs tri-level error diffusion on the input image by halftoning the input image into black, white and 50% gray. A plurality of halftoning circuits successively replace each pixel of the halftoned input image with one of a plurality of the 2&#xd7;2 binary patterns. The one of the plurality of 2&#xd7;2 binary patterns corresponds to at least one respective bit of the watermark data when a pixel of the halftoned image data is 50% gray. The watermark data can be segmentation map data of the input image.

Watermarked image generator and method of embedding watermarks into an input image

A method and system for image processing, in conjunction with classification of images between natural pictures and synthetic graphics, using SGLD texture (e.g., variance, bias, skewness, and fitness), color discreteness (e.g., RL, RU, and RV normalized histograms), or edge features (e.g., pixels per detected edge, horizontal edges, and vertical edges) is provided. In another embodiment, a picture/graphics classifier using combinations of SGLD texture, color discreteness, and edge features is provided. In still another embodiment, a 'soft' image classifier using combinations of two (2) or more SGLD texture, color discreteness, and edge features is provided. The 'soft' classifier uses image features to classify areas of an input image in picture, graphics, or fuzzy classes.

Picture/graphics classification system and method

A method and system for image processing, in conjunction with classification of images between natural pictures and synthetic graphics, using SGLD texture (e.g., variance, bias, skewness, and fitness), color discreteness (e.g., R_L, R_U, and R_V normalized histograms), or edge features (e.g., pixels per detected edge, horizontal edges, and vertical edges) is provided. In another embodiment, a picture/graphics classifier using combinations of SGLD texture, color discreteness, and edge features is provided. In still another embodiment, a 'soft' image classifier using combinations of two (2) or more SGLD texture, color discreteness, and edge features is provided. The 'soft' classifier uses image features to classify areas of an input image in picture, graphics, or fuzzy classes.

Soft picture/graphics classification system and method

This invention relates to a method and apparatus for segmenting an image using a combination of image segmentation techniques. More particularly, the invention is directed to an improved image segmentation technique for use in an image processing system that performs at least two distinct image segmentation processes on an image and combines the results to obtain a combined multi-layer representation of the image that can be suitably processed. In a specific example, a block based segmentation technique is performed on an image to generate a MRC (mixed raster content) representation&#x2014;having foreground, background and selector layers. A pixel based segmentation technique is also performed on the image to generate rendering hints. The MRC representation and the rendering hints are then combined to obtain a four (4) layer representation of the image. The four layer representation is subsequently processed as required by the image processing system, e.g. compressed and stored.

Growing community of inventors

Penfield, NY, United States of America

Ying-wei Lin