Xerox Corporation

David Jon Metcalfe

Jeng-nan Shiau

Leon C Williams

Xing Li

Stuart Alan Schweid

Ryan David Metcalfe

David Allen Mantell

Roger Lee Triplett

Zhenhuan Wen

Robert P Robideau

Francis Kapo Tse

Jagdish C Tandon

Scott L Tewinkle

Stephen Michael Kroon

Raymond J Clark

Joseph P Taillie

John T Newell

Joel Chan

Xiao-fan Feng

Howard A Mizes

Paul Allen Hosier

Clara Cuciurean-Zapan

Yingjun Bai

Meng Yao

Josef E Jedlicka

Barbara Lynn Farrell

Mark Raymond Parker

Peter D McCandlish

James Bruce Campbell

Martin L Frachioni

Douglas Dean Darling

Terri A Clingerman

Michael Dale Stevens

Theresa Michelle Marconi

Louis Ba La

Mihai Cuciurean-Zapan

John F Seward, Jr

Yungran Choi

Richard B Eaton

John Adam Handwork

Paul W Phillippi

Chao Yu

Dawn M Williams-Fuller

An image processing device includes an input device which receives image adjustment selections from an associated user interface device. Memory of the device stores a user interface generator, which generates a background adjustment selector for presenting to a user on the user interface device; a background adjustment component which, for each of a plurality of pixels of an input image computes adjusted color values, as a function of at least one of: (a) a background adjustment factor computed for the respective pixel, and (b) a background class derived from the computed background adjustment factor, the background adjustment factor being a function of a background strength of the pixel and a luminance strength of the pixel; and an image output component outputs an output image derived from the adjusted color values for the plurality of pixels. A processor implements the background adjustment component and image output component.

System and method to detect, suppress, and modify background regions of scanned documents

An image processing device includes a neutral edge detection and enhancement component which, for pixels of an input image, computes an edge strength for the pixel as a function of differences between the input luminance value of the pixel and input luminance values of neighboring pixels, computes a neutral adjustment factor for the pixel as a function of the input luminance value of the pixel, and computes a chroma adjustment factor for the pixel as a function of the input chrominance values of the pixel. An adjusted luminance value for the pixel is computed as a function of the input luminance value, the edge strength, and the neutral adjustment factor. Adjusted chrominance values for the pixel may be computed as a function of the input chrominance value, the edge strength, and the chroma adjustment factor. The system allows detection and enhancement of neutral edges in monochrome and color images.

System and method for processing and enhancing achromatic characters of scanned digital documents

An image processing device and method are provided for adjusting background pixels of an image. The device includes memory which stores a background adjustment component which for each of a plurality of pixels of an input image: computes a background strength of the pixel; computes a luminance strength of the pixel; and computes adjusted luminance and adjusted chrominance values for the pixel, as a function of the background strength and luminance strength of the pixel. An image output component outputs an output image derived from the adjusted luminance and adjusted chrominance values for the plurality of pixels, A processor implements the background adjustment component and image output component.

System and method to detect and adjust image background

An image processing system and method are described which use entropy values in processing the image. For each of a plurality of segments of an image, the segment is considered as a stream of bits and a bit difference is computed between pairs of sequential bit sequences in the stream of bits. An entropy value of the segment is computed as a function of the bit differences. The image is processing based on the computed entropy values, which may include compressing some or all of the image segments using an acceleration factor that is based on the computed entropy value for the segment. In this way, differences in entropy, which correlate with the compressibility of the image segment, can ensure an optimal compression of the segment, or in some cases, no compression.

Dynamic compression acceleration using real-time image data entropy analysis

A method of printer operation identifies inkjets to operate in each scanline to eject sneeze drops or, in an alternative approach, identifies the cross-process direction scanlines within a page to be printed by the printer where each inkjet ejects sneeze drops. The methods use a binary grayscale code counter that generates a sequence of binary grayscale code numbers and every other output of the sequence is bit reversed to spread the sneeze drops over the pages of the printer output so the sneeze drops are not perceptible to a human observer.

Methods for operating printhead inkjets to attenuate ink drying in the inkjets during printing operations

An inkjet printer that is configured to perform multi-pass printing operations includes at least one printhead, a memory and a controller. The controller receives a input row of image data for one pass including a plurality of pixels. The controller uses a table of index lookup offsets in the memory to generate a row of output image data with at least one pixel at a first index in the input row being located at a second index in the output row. The controller operates the inkjets in the printhead to eject at least one drop of ink using an inkjet in the printhead that corresponds to the second index in the output row and that is different than another inkjet in the printhead that corresponds to the first index in the input row.

System and method for control of inkjets in inkjet printers

A method for operating an inkjet printhead includes identifying a number of ink drop ejections for an inkjet in the printhead to form a printed image with reference to image data corresponding to the printed image and generating control data that specify a sequence of a plurality of non-firing electrical signals to be applied to the inkjet with reference to a predetermined control sequence stored in a memory and the number of ink drop ejections. The method further includes generating non-firing electrical signals applied to the inkjet with reference to the control data and generating a plurality of firing electrical signals applied to the inkjet to eject ink drops after generating every non-firing electrical signal in the plurality of non-firing electrical signals.

System and method for generation of non-firing electrical signals for operation of ejectors in inkjet printheads

A method, non-transitory computer readable medium and apparatus for starting a multiple scanline error diffusion method are disclosed. For example, the method includes identifying a pixel for each scanline of a plurality of scanlines, wherein the pixel that is identified in the each scanline of the plurality of scanlines is offset, setting all pixels behind the pixel for the each scanline of the plurality of scanlines that is identified with a white pixel value and starting the multiple scanline error diffusion method.

Method and apparatus for starting an error diffusion method

Image scaling disclosed herein comprises receiving an image from an image capturing device and partitioning an image into at least one image tile using a partitioning module. A determination is made if the image tile requires slow scan scaling and/or fast scan scaling. The image tile is subject to slow scan scaling. The image tile is then transposed, scaled in the fast scan direction, and then again transposed to an original orientation. The tile is reassembled into a scaled image and may be rendered by a rendering device.

Vectorized two stage tile-based scaling

A method of compensating for an inoperable inkjet in an inkjet printer that forms printed images with multiple drop sizes has been developed. The method includes identifying at least one neighboring pixel in a region of multi-bit halftoned image data around a pixel corresponding to the inoperable inkjet and modifying the at least one neighboring pixel to enable an inkjet that neighbors the inoperable inkjet to eject an ink drop during printing operation to compensate for the inoperable inkjet.

System and method for missing inkjet compensation in a multi-level inkjet printer

An image processor determines the number of pixels to be added/removed within each row/column of pixels of an image to accomplish a given image enlargement/reduction. The image processor evenly distributes pixels that are to be added/removed along the full length of each of the rows or columns of pixels, and adds/removes pixels in a process that identifies a set of original pixels that are immediately adjacent to the pixel to be added/removed. The image processor then replaces each of the sets of the original pixels with a replacement set (that has one more/less pixel relative to the set of original pixels). Also, for each pixel that will be added/removed, the image processor determines data values for replacement pixels in each of the replacement sets by weighting data values from original pixels in the sets of original pixels. The image processor outputs an enlarged/reduced size version of the input image.

Simultaneous duplex magnification compensation for high-speed software image path (SWIP) applications

Embodiments relate to systems and methods for a computation-efficient image processing system architecture. Image data can be transmitted from a computer, online service, and/or other image source to an output device having a set of image processing modules in two or more image paths, including an edge detection module and a video decoding module. The edge detection module can produce edge tag output, and the video decoding module, operating in parallel, can generate decoded video output. The edge tag output and decoded video output can be transmitted to a set of downstream image processing modules, including modules for color trapping, edge smoothing, and other operations. Because earlier processing stages share information with downstream modules which require the same or related data, redundant processing can be reduced or eliminated. Complex image operations can therefore be carried out, and high-quality output can be generated, without sacrificing responsiveness.

Systems and methods for computation-efficient image processing system architecture

Methods and systems render higher bit per pixel contone images to lower bit formats using multiple registers of a SIMD processor. The rendering process uses a first register to maintain contone image values of all the pixels being simultaneously processed. A second register maintains a threshold value used during the conversion process. A third register maintains one value for the print ready format pixels (e.g., those having less bits per pixel), and a fourth register maintains the other value (e.g., 0) for the print ready format pixels. Also, a fifth register maintains the conversion error amount for all the pixels being simultaneously processed. Sixth through ninth registers maintain distributed conversion error amounts produced by the diffusing process (for different pixels being simultaneously processed); and a tenth register maintains the pixels in the print-ready format produced by the conversion for all the pixels being simultaneously processed.

Rendering images to lower bits per pixel formats using reduced numbers of registers

Methods and systems for processing a low resolution image via a low resolution error diffusion algorithm. A low resolution binary output pixel can be generated utilizing a general error diffusion algorithm. The low-resolution binary output pixel can be converted to a predetermined number of interpolated sub-pixel values and each interpolated sub-pixel values can be compared with a threshold in order to generate a scaled slow-scan output pixel utilizing the low resolution error diffusion algorithm. The low resolution error diffusion algorithm includes a highlight threshold adjustment module that adjusts level in order to prevent the scaled slow-scan output pixel from firing around the low resolution binary output pixel within a highlight region. A slow scan error with respect to the scaled slow-scan output pixel can be distributed and stored via error diffusion filter coefficients within an error buffer without additional memory.

Methods and systems for processing low resolution images via error diffusion

A method, non-transitory computer readable medium, and apparatus for performing error diffusion are disclosed. For example, the method quantizes an error for a first pixel of a plurality of pixels in a first row, diffuses the error to an adjacent pixel of the plurality of pixels in the first row, performs the quantizing and the diffusing for each remaining pixel of the plurality of pixels in the first row and applies the error that is quantized for each one of the plurality of pixels the first row in a desired number of different directions in a plurality of parallel operations that is equal to the desired number of different directions.

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Marion, NY, United States of America

David Jon Metcalfe