Xerox Corporation

Calos Fund Limited Liability Company

Donald James Curry

Doron Kletter

Asghar Nafarieh

Douglas N Curry

Fritz F Ebner

Ujval J Kapasi

Todd W Thayer

Pradeep S Sindhu

Jean-Marc Frailong

Ramesh Nagarajan

Francis Kapo Tse

John C Handley

Peter A Crean

Robert Roy Buckley

James Loran Ball

David Birnbaum

Stuart L Claassen

Daniel C Kowalski

Gordon R Knight

David Kasle

In a single-instruction-multiple-data (SIMD) processor having multiple lanes, and local memory dedicated to each lane, a method of processing an image is disclosed. The method comprises mapping consecutive rasters of the image to consecutive lanes such that groups of consecutive rasters form image strips, and vertical stacks of strips comprise strip columns. Local memory allocates memory to the image strips. A sequence of functions is processed for execution on the SIMD processor in a pipeline implementation, such that the pipeline loops over portions of the image in multiple iterations, and intermediate data processed during the functions is stored in the local memory. Data associated with the image is traversed by first processing image strips from top to bottom in a left-most strip column, then progressing to each adjacent unprocessed strip column.

Chaining image-processing functions on a SIMD processor

Method for chaining image-processing functions on a SIMD processor

Systems and methods are described that facilitate encrypting document status information into a scanned image of a document using a mixed raster content document parsing protocol, in accordance with various features described herein. A text string comprising status information can be imaged into a mask layer that overlays the scanned image. Additionally or alternatively, the text string can be encrypted into a binary image that is encoded into the mask layer and overlaid on the image. The image itself is parsed into a background layer and one or more mask layers comprising different portions of the document. The encrypted mask layer comprising the text string and/or binary image can be generated using the same color as the background layer, such that the document status information is invisible and does not cause unwanted artifacts during printing or conversion of the document between formats. The document status information can be scanner signature information, scan-to-file authentication information, object metadata, etc.

Preserving scanner signature using MRC technology

An image background remover is disclosed that performs background removal of JPEG (Joint Photographic Experts Group) compressed image data without first performing a complete decompression of the compressed image data.

Compressed image data enhancement

An image processing system as disclosed, including at least one input processing device functionally coupled to at least one output processing device, document information configured in a format such as scanning format or a document creating format converted to a common exchange format, and a common exchange format being converted to a format such as a document viewing format or document printing format. An image processing method also disclosed, including inputting document information, converting inputted document information configured in a document format such as a scanning format or a document creating format to a common exchange format, and converting the common exchange format to a document format such as a document viewing format or a document marking format.

Common exchange format architecture for color printing in a multi-function system

Apparatus and methods for de-screening an image signal utilizing a bank of filters to provide several increasingly blurred versions of the original image signal is disclosed. At any given time, one or more of the blurred versions are created, on a pixel-by-pixel basis. The outputs from a selected pair of blurred signals are then blended together to create a variable blending output that can vary smoothly from no blurring to maximum blurring in a smooth and continuous manner. In addition, the apparatus and methods provide enhanced text and line art by using a variable un-sharp masking mechanism with independent post-blur sharpening control, and detect and enhance neutral (no-color) output pixels.

Apparatus and methods for de-screening scanned documents

A method and a system for dynamically thresholding an image signal. The system comprises a computing block. The computing block receives the image signal and a minimum and a maximum within each of a set of windows centered on the current pixel in the image signal, and computes, for each of the windows, based on the current pixel and the respective minimum and maximum, a respective indicator representing the distance and direction of the current pixel relative to a respective threshold plane, and outputs a control signal based on the indicators.

Segmentation method and system for multiple raster content (MRC) representation of documents

A method and system for de-screening an image signal utilizing a bank of filters to provide several increasingly blurred versions of the original image signal is disclosed. At any given time, only two of these blurred versions are created, on a pixel-by-pixel basis. The outputs from the selected pair of blurred signals are then blended together to create a variable blending output that can vary smoothly from no blurring to maximum blurring in a smooth and continuous manner. In addition, the method provides the capability to enhance text and line art by using a variable un-sharp masking mechanism with independent post-blur sharpening control, and the capability to detect and enhance neutral (no-color) output pixels.

Digital de-screening technique for scanned documents

The image data is analyzed to identify blobs having similar characteristics. Various blobs are gathered together and placed into a foreground plane based on one or more color characteristics and/or spatial characteristics. Each blob gathered onto a foreground plane has a color that is similar to a color associated with that foreground plane. One or more portions of the image data that is not mapped into any foreground plane may be mapped into a background plane.

Systems and methods for generating high compression image data files having multiple foreground planes

Image data is analyzed line by line to identify pixels having similar color and edge characteristics. The pixels on one line are linked to pixels on another line, if they share similar characteristics. The linked pixels are then grouped together in regions and the average color of the region is calculated. An image map is generated that identifies the regions to which the pixels belong, along with a final table of the regions appearing in the image.

Systems and methods for connecting regions image data having similar characteristics

A method and a system for computing the function value of an input node based on function values of known nodes. A database of known nodes and their corresponding function values is formed. The known nodes are located such that a distance between any two adjacent known nodes is an integer power-of-two number. The database is searched for a first node such that the input node is located between the first node and an adjacent second node. The difference &#x3b4; between the input node and the first node is computed. Then &#x3b4; is shifted to the right by k positions, k being the logarithm in base 2 of the distance between the first and second nodes. The input node function value is computed by combining the first node function value with the product of the shifted &#x3b4; and the difference between the function values of the second and first nodes. When used in MRC context, the above method and system is applied to each of the color MRC planes individually, instead of the merged output. The resulting performance is approved since most if not all of the color MRC planes are sub-sampled.

Efficient interpolation technique using programmable node spacing

A blob identifier uses edge continuity signal to analyze how to combine the current pixel into an existing blob or into the background image, or start a new blob. The blob identifier outputs a list of blob identifiers on a line-by-line basis.

Systems and methods for identifying regions within an image having similar continuity values

An efficient method and system for eliminating halftone screens from scanned documents while preserving the quality and sharpness of text and line-art is disclosed. The method and system utilizes one or more independent channels with different sensitivities (e.g., Max, High, and Low) to provide high quality frequency and magnitude estimation. The most sensitive channel (Max) derives the frequency estimate, and the remaining channels (e.g., High and Low) are combined to create the screen magnitude. The Max channel is the most sensitive and will usually report the existence of frequencies even when the screen is very weak. Therefore, the screen frequency must be additionally qualified by the screen magnitude. The screen magnitude can be interpreted as the level of confidence that the local neighborhood represents half-toned data.

Halftone screen frequency and magnitude estimation for digital descreening of documents

A highly efficient method and system for eliminating halftone screens from scanned documents while preserving the quality and sharpness of text and line-art is disclosed. The method and system utilizes a single channel screen frequency estimator module, which generates a screen frequency estimate for image data. The module generates a signal based on the highly filtered image signal at low contrast levels, and based on a reliable estimate to the halftone frequency at higher contrast levels. The single channel screen estimate module has adequate performance in resolution ranges from 300 to 600 dpi.

The image data is processed into a background plane and a plurality of foreground planes. Holes are inserted onto the background plane, in regions which are assigned to a foreground plane. The background plane is sub-sampled, and holes remaining in the sub-sampled image are filled with the average color of the non-zero sub-sampled pixels over pre-determined blocks such as JPEG blocks. If a block is entirely made of holes, the block is filled with a constant color that is propagated from the average color of a previous block. The resulting background plane is far smoother than the original image data and thus can be effectively sub-sampled and highly compressed without adverse deterioration in reconstructed image quality.

Growing community of inventors

Menlo Park, CA, United States of America

Donald James Curry