Adaptive Error Diffusion Patents (Class 358/3.05)
  • Patent number: 8416457
    Abstract: A printing apparatus is adapted to perform printing of image data corresponding to a plurality of pixels representing a predetermined image. The printing apparatus includes a halftone processing section including a comparison section and an error diffusion section. The comparison section is configured to compare, for at least one of the pixels, a related grayscale value relating to a data grayscale value of the input image data with a corresponding one of a plurality of thresholds included in a dither mask. The error diffusion section is configured to generate dot data for indicating the presence or absence of formation of a dot in each of the pixels according to an error diffusion method, on the basis of the data grayscale values of the input image data, and to control the easiness of the dot formation according to the error diffusion method, on the basis of a comparison result of the comparison section.
    Type: Grant
    Filed: July 6, 2010
    Date of Patent: April 9, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Toshiaki Kakutani
  • Patent number: 8405876
    Abstract: When multi-pass printing is performed, the dot overlap rate (ratio of the number of dots that overlap and are to be printed in the same pixel area by the plurality of relative movements with respect to the total number of dots to be printed in a pixel area by the plurality of relative movements) in pixel areas having medium-density where density unevenness caused by density fluctuation easily stands out is made higher than the dot overlap rate in pixel areas having low-density and pixel areas having high-density. By doing so density unevenness caused by density fluctuation is suppressed. In addition, the dot overlap rate in pixel areas having low-density and pixel areas having high-density is low, so it is possible to reduce graininess in low-density areas and suppress a decrease in density in high-density areas.
    Type: Grant
    Filed: June 11, 2010
    Date of Patent: March 26, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akihiko Nakatani, Fumihiro Goto, Akitoshi Yamada, Mitsuhiro Ono, Okinori Tsuchiya, Fumitaka Goto, Takashi Fujita, Rie Kajihara, Ayumi Sano, Tomokazu Ishikawa
  • Patent number: 8390891
    Abstract: A quantizing unit, error detector, error diffusion matrix, and adder quantize a pixel of interest of an input image by an error diffusion method. A calculation unit and gain adjuster calculate a value to be added to the pixel of interest with reference to quantized pixels. The adder adds the calculated value to the pixel of interest. A control unit controls the calculation of the gain adjuster.
    Type: Grant
    Filed: March 29, 2012
    Date of Patent: March 5, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventor: Naoto Kawamura
  • Patent number: 8368979
    Abstract: An image forming apparatus includes a tone correction storage unit that stores a plurality of tone correction charts for correcting tone of image data; a determination unit that determines characteristics of the image data; a selection unit that selects a tone correction chart suitable for the image data from the plurality of tone correction charts stored in the tone correction storage unit; a chart print unit that prints the tone correction chart selected by the selection unit on a sheet; a receiving unit that receives an adjustment value inputted based on the tone correction chart printed by the chart print unit; a tone correction unit that corrects tone of the image data based the adjustment value; and a print unit that prints out the image data after correcting tone of the image data.
    Type: Grant
    Filed: August 17, 2009
    Date of Patent: February 5, 2013
    Assignee: Fuji Xerox Co., Ltd.
    Inventors: Kiyoshi Une, Takaya Nagasaki, Hiroyuki Kawai, Yasuo Komatsu, Seiji Shiraki, Takumi Nishikata
  • Patent number: 8363279
    Abstract: A disclosed method for setting multiple tones in a halftone process upon recording an image using ink includes the steps of: dividing the image into plural dot areas; and setting the multiple tones such that at least one dot area to which the ink is not attached is present between dot areas to which the ink is attached.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: January 29, 2013
    Assignee: Ricoh Company, Ltd.
    Inventors: Naoki Kikuchi, Takashi Kimura, Takahiro Ike
  • Patent number: 8363278
    Abstract: The present invention relates to a method and apparatus capable of generating frequency-modulation halftone dots in high speed and belongs to the field of the digital image halftone. In the prior art, read-write operation is usually carried out many times in error rows during processing each pixel so that halftone dots are generated in low speed. In the method according to the present invention, the error generated by the current pixel is buffered in a register file and the final accumulated error values are written in the error rows only after all of the relative pixels are processed. Thus, read-write operation is carried out only once in the error rows for processing each pixel. The present invention also provides an apparatus to implement the method. The apparatus comprises an error row memory, an error buffer register file, a gray generation circuit, a threshold comparison circuit, an error generation circuit, an error buffer register file control circuit, and an error row control circuit.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: January 29, 2013
    Assignees: Peking University Founder Group Co., Ltd., Beijing Founder Electronics Co., Ltd., Peking University
    Inventors: Zhihong Liu, Feng Chen, Bin Yang
  • Patent number: 8363271
    Abstract: A method for controlling an image processing apparatus includes obtaining image data from a detachable memory unit, estimating whether the obtained image data is image data read by a scanner, and in a case where it is estimated that the obtained image data is image data read by the scanner, performing control not to execute predetermined screen processing on the image data.
    Type: Grant
    Filed: June 5, 2009
    Date of Patent: January 29, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Yoshiharu Ikegawa, Koki Shibao
  • Patent number: 8363282
    Abstract: A method of processing a continuous tone image includes using a halftone screen to generate a bi-level bitmap; partitioning the contone image into an array of image blocks; halftoning the image blocks; using the bi-level bitmap to select some of the halftone image blocks; and modifying the selected halftone image blocks using code words, such that information contained in the code words is embedded in a halftone image. A method of extracting embedded information in a halftone image includes accessing a bi-level bit map; partitioning the halftone image into a plurality of image blocks; using the bitmap to select at least some of the blocks; identifying a code word sequence in the selected blocks; and extracting the information from the code word sequence.
    Type: Grant
    Filed: October 31, 2003
    Date of Patent: January 29, 2013
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Niranjan Damera-Venkata
  • Patent number: 8351084
    Abstract: A mechanism for providing edge enhancement or attenuation in a vector error diffusion process includes warping a marking decision color space as a function of at least one pixel value of a target pixel. The warping changes the membership of sets of error modified pixel values associated particular sets of marking. The warping is controlled by a function of pixel values of a target pixel from an input image. Therefore, the warping is constant for uniform portions of the image. Since pixel values change at edges or where colors change, a mechanism is provided for the presence of edges to influence the vector error diffusion process. Selection of the function by which the marking decision color space is warped provides a means for controlling the aggressiveness of the edge enhancement or attenuation. Equivalent processing includes warping or adjusting error modified pixel values according to corresponding functions.
    Type: Grant
    Filed: October 13, 2009
    Date of Patent: January 8, 2013
    Assignee: Xerox Corporation
    Inventors: Edgar A. Bernal, Robert P. Loce
  • Patent number: 8351083
    Abstract: Image data of a pixel of interest is inputted, diffusion data diffused from errors occurred by decrease of a tonal number of image data is added to the image data of the pixel of interest, the tonal number of the image data of the pixel of interest, to which the diffusion data has been added, is decreased using an error diffusion method or minimized average error method, and an error occurred in the decrease of the tonal number for the pixel of interest is diffused to pixels close to the pixel of interest. Further, the errors occurred by the decrease of the tonal number of the image data in a predetermined image region are integrated as an integrated error, and a threshold value used in the error diffusion method or minimized average error method is set based on the image data of the pixel of interest and the integrated error.
    Type: Grant
    Filed: April 14, 2009
    Date of Patent: January 8, 2013
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shoei Moribe, Takashi Ochiai
  • Patent number: 8339673
    Abstract: A method and apparatus for processing an image are provided that can suppress blur edges at an edge portion of a character so that sharpness and quality of the image can be improved. The apparatus comprises an inside and outside edge discrimination portion for discriminating whether a target pixel to be processed belongs to an inside edge or to an outside edge, a threshold value generating portion for selecting a threshold value from plural threshold values for error diffusion process in accordance with an area discriminated by the inside and outside edge discrimination portion to output the selected threshold value and an error diffusion process portion for performing the error diffusion process for multilevel input data concerning the target pixel by utilizing the threshold value generated by the threshold value generating portion so as to produce output data whose gradation steps are reduced.
    Type: Grant
    Filed: June 5, 2003
    Date of Patent: December 25, 2012
    Assignee: Minolta Co., Ltd.
    Inventor: Taisuke Akahori
  • Patent number: 8294952
    Abstract: A halftoning process includes: receiving CMYK input pixel data in terms of continuous tone input data values for cyan, magenta, yellow, and black colors converting the CMYK input pixel data to modified CMYKRGB* pixel data that define the input pixel in terms of error-adjusted continuous tone data values quantizing the modified CMYKRGB* pixel data to derive intermediate output CMYKRGB pixel data in which the cyan, magenta, yellow, black, red, green, and blue colors are each defined by either a first quantized value that represents no color or a second quantized pixel value that represents full color converting the intermediate output CMYKRGB pixel data to CMYK output data.
    Type: Grant
    Filed: November 5, 2009
    Date of Patent: October 23, 2012
    Assignee: Xerox Corporation
    Inventors: Zhigang Fan, Zhen He
  • Patent number: 8284452
    Abstract: A method is disclosed for screening color separations of a lenticular image with a lenticular frequency of the lenticular lenses needed for viewing the lenticular image. An amplitude-modulated halftone image is calculated for each of the color separations at a screen angle and at a screen frequency, the tangent of the screen angle being a rational number. For a specific color separation, a screen angle relating to the direction perpendicular to the image strips of the lenticular image is defined, a pair of whole numbers whose ratio is equal to the tangent of the screen angle is determined, and the screen frequency of the color separation is calculated as the product of the lenticular frequency and the square root of the sum of the squares of the two whole numbers.
    Type: Grant
    Filed: May 19, 2009
    Date of Patent: October 9, 2012
    Assignee: Heidelberger Druckmaschinen AG
    Inventor: Dietrich Blum
  • Patent number: 8279489
    Abstract: A technique for performing high-quality cluster type FM halftone image output without “anisotropy” or “sweep out texture” phenomenon is provided. An error diffused to a current pixel position and a random number RND are added by an adder to multi-level pixel data as a subject of binarization, and supplied as pixel data Pxy to a selector. The selector compares the pixel data Pxy with thresholds, and supplies the pixel data Pxy to one of a highlight portion processor, a dark portion processor and an intermediate portion processor. The highlight and dark portion processors refer to already-binarized results within a range determined in accordance with the value of the input pixel data Pxy, and determine a binarization result Qxy. The intermediate portion processor compares a threshold, which monotonously increases in accordance with the value of the pixel data Pxy, with the pixel data Pxy, thereby determines the binarization result Qxy.
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: October 2, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Naoto Kawamura
  • Patent number: 8274705
    Abstract: Machine-enabled methods of, and system, and processor readable media, embodiments for, tone quantization error diffusion comprising a first stage process and a second stage process. where pre-calibrated index tables may be applied by which quantized pixels may be expressed according to halftones.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: September 25, 2012
    Assignee: Sharp Laboratories of America, Inc.
    Inventor: Ching-Wei Chang
  • Patent number: 8259358
    Abstract: A method for eliminating moire in scanned digital image comprises the steps of using an average circuit for taking weighted average and error diffusing a gray level difference between an error diffusion pixel Gij and neighbor pixels to neighbor to obtain output image pixel Y?ij; using a second adder for subtracting the error diffusion pixel Gij from the output image pixel Y?ij to obtain a neighbor image error dij; using a error filter H(z) to process the neighbor image error dij to obtain a corrected pixel error H(d(i,j)); and using a first adder for adding the corrected pixel error H(d(i,j)) and the input image pixel Yij to obtain the corrected error diffusion pixel Gij, and then jumping to first step until all pixels being processed. The method provides real time treatment for eliminating moire and provide smooth image.
    Type: Grant
    Filed: November 7, 2007
    Date of Patent: September 4, 2012
    Assignee: Muller Capital, LLC
    Inventors: Chen-Chung Chen, Cheng-Huei Chiang
  • Publication number: 20120188609
    Abstract: An image processor includes a color conversion unit that generates color converted image data by converting color data and an error diffusion process performing unit that generates print data by performing an error diffusion process on the color converted image data. The error diffusion process performs a first error diffusion process on remaining data and performing a second error diffusion process on edge data such that an amount of ink used in the edge region by performing the second error diffusion process on the edge data is less than an amount of ink used in the edge region by performing first error diffusion process on the edge data.
    Type: Application
    Filed: January 19, 2012
    Publication date: July 26, 2012
    Applicant: BROTHER KOGYO KABUSHIKI KAISHA
    Inventor: Masashi KUNO
  • Publication number: 20120176650
    Abstract: A digital halftoning method and a method for constructing a class tiling map are disclosed. The present invention utilizes to arrange class matrixes in a staggering form such that adjacent class matrixes exist a staggering shift. Also, the class tiling map is constructed in this way. Then, a dot diffusion procedure is performed to an original image with the class tiling map so as to generate a halftone image corresponding to the original image. The present invention is capable of solving the problem of a periodic appearance caused by traditional dot diffusion.
    Type: Application
    Filed: June 3, 2011
    Publication date: July 12, 2012
    Applicant: National Taiwan University of Science and Technology
    Inventors: Jing-ming Guo, Yun-fu Liu
  • Patent number: 8213054
    Abstract: An image processing apparatus includes a dividing portion that divides input multivalue image data into a plurality of bands, an error diffusion process portion that carries out an error diffusion process on each divided band to quantize each pixel, and a controlling portion that controls the dividing portion and error diffusion process portion. The error diffusion process portion, following control by the controlling portion, operates in a first mode to repeat the error diffusion process not accompanying quantization given times on each noted pixel included in a given line of the each band (head line, etc.), and operates in a second mode to carry out the error diffusion process on the each band sequentially from the head line of the each band on the basis of an error value obtained in the first mode to put out quantized data.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: July 3, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Michiyuki Suzuki
  • Patent number: 8203757
    Abstract: A method for improving printing quality of a digital image using error diffusion screening including the steps for each pixel in a digital image: a) initialize weighted error diffusion value; b) translate first value (220) of each pixel of the digital image to a second value (916); c) translate the second value of each pixel of the digital image to create a third value (920); d) translate the third value of each pixel of the digital image by adding the error diffusion value (216) to create a fourth value (224); e) generate a quantization value for each pixel in the digital image by using at least one threshold value; f) perform geometrical distribution in space of the first quantization (924) utilizing a first pixel mask (1604) and possibly a second pixel mask for setting pixels in designated areas defined by the pixel masks; and g) update said error diffusion value and go to step (b) till all the pixels of the digital image are treated.
    Type: Grant
    Filed: December 14, 2009
    Date of Patent: June 19, 2012
    Assignee: Eastman Kodak Company
    Inventor: Michel Keselbrener
  • Patent number: 8199363
    Abstract: An image processing method and an image processing apparatus converts a binary image into a grayscale image by increasing the size and information quantity of the binary image. The image processing method includes generating a plurality of lookup tables having multiple gray level values assigned to a predetermined pattern of the binary image such that the gray level is retrieved from the plurality of lookup tables depending on the context of the block being processed. The binary image may be converted into the grayscale image by applying the gray value of one of the plurality of lookup tables that corresponds to the context, such as the frequency components of the binary image. With this configuration, since the size and information quantity of an image can be reduced for transmission, it is possible to prevent deterioration of image quality when the image is restored, while also printing at a higher speed.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: June 12, 2012
    Assignee: SAMSUNG Electronics Co., Ltd.
    Inventors: Woo-jun Chung, Sang-youn Shin, Choon-woo Kim, Byong-tae Ryu, Jong-ok Lee
  • Patent number: 8169664
    Abstract: A quantizing unit, error detector, error diffusion matrix, and adder quantize a pixel of interest of an input image by an error diffusion method. A calculation unit and gain adjuster calculate a value to be added to the pixel of interest with reference to quantized pixels. The adder adds the calculated value to the pixel of interest. A control unit controls the calculation of the gain adjuster.
    Type: Grant
    Filed: March 27, 2009
    Date of Patent: May 1, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventor: Naoto Kawamura
  • Patent number: 8169665
    Abstract: A tone dependent green-noise error diffusion method includes setting a first threshold and a second threshold, and determining a two-level value of a color level of an input image according to the first threshold and the second threshold; subtracting the two-level value from the color level value to generate an error value; performing an error diffusion on the error value to generate an error diffusion accumulation value; adjusting the color level according to the error diffusion accumulation value; performing a hysteresis filtering on the two-level value to generate an output dependent feedback value; and adjusting the color level according to the output dependent feedback value.
    Type: Grant
    Filed: March 30, 2009
    Date of Patent: May 1, 2012
    Assignees: Silitek Electronic (Guangzhou) Co., Ltd., Lite-On Technology Corp.
    Inventors: Wen-Chian Wong, Chen-Chung Chen
  • Patent number: 8169663
    Abstract: An image processing apparatus includes (i) a repulsive force generating section for setting repulsive force values RVa and RVu of a quantized pixel according to an output pixel value of the quantized pixel, (ii) a repulsive force calculating section for calculating a repulsive force value RVC to be used in quantizing a quantization-target pixel by attenuating, according to a distance between the quantized pixel and the quantization-target pixel, the repulsive force values RVa and RVu set for the quantized pixel; and (iii) a threshold value correcting section for correcting a threshold value T used in quantizing the quantization-target pixel according to the repulsive force value RVC. This makes it possible to prevent an increase in the number of processing steps and amount of processing when an image is processed with an error diffusion method. At the same time, it is possible to prevent decrease in image uniformity and formation of a pattern unique to the error diffusion method.
    Type: Grant
    Filed: March 25, 2009
    Date of Patent: May 1, 2012
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Hideyoshi Yoshimura
  • Patent number: 8159720
    Abstract: Halftoning is performed on a source image. The halftoning includes error diffusion processing of one separation based on error diffusion processing of another separation. The error diffusion processing includes determining a rendered pixel value for the one separation by applying a quantization function for a given pixel. The quantization function is based on both a modified input determined as a function of an error value of a pre-rendered pixel for the one separation and an error value determined as a function of rendered pixel values for the another separation. A rendered image is output, which includes the same plural color separations. The output rendered image is populated with, for the one separation, a rendered pixel value based on the application of the quantization function.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: April 17, 2012
    Assignee: Xerox Corporation
    Inventor: Zhigang Fan
  • Patent number: 8134749
    Abstract: An image processing system including a lookup table having multi-bit printer output levels and an imaging input level. The imaging input level may be associated with a range of input pixel densities. The system further includes a processor configured to compare the imaging input level with one or more preconfigured threshold output values associated with the printer output levels. The imaging input level may be preferentially weighted to select a printer output level having an increased bit depth.
    Type: Grant
    Filed: May 25, 2007
    Date of Patent: March 13, 2012
    Assignee: Sharp Laboratories of America, Inc.
    Inventor: Ching-Wei Chang
  • Patent number: 8107772
    Abstract: Disclosed is an image processing apparatus including a tone converting section to convert a tone level of a target pixel in multi-level image data based on a threshold value of the tone level so that the number of tone levels is reduced; a resolution converting section to output a pixel block according to the tone level, to generate image data with higher resolution; and an error diffusing section to diffuse an error; and wherein when the converted tone level is a predetermined value or lower, the resolution converting section refers to an output sequence category of a black pixel in a pixel block of a surrounding pixel, selects an output sequence pattern belonging to an output sequence category which allows a black pixel in a pixel block of the target pixel and the surrounding pixel to be concentrated, and outputs a pixel block corresponding to the selected pattern.
    Type: Grant
    Filed: August 15, 2007
    Date of Patent: January 31, 2012
    Assignee: Konica Minolta Business Technologies, Inc.
    Inventor: Mieko Ohkawa
  • Patent number: 8098403
    Abstract: A method for multi-toning an input digital image having input pixels with two or more color channels to form an output digital image having modified output levels. The method includes determining modified output levels using a combined error signal formed from intermediate error signals for each color channel together with an error signal offset value, and adjusting the input levels for the nearby pixels responsive to weighted error signals.
    Type: Grant
    Filed: May 11, 2011
    Date of Patent: January 17, 2012
    Assignee: Eastman Kodak Company
    Inventors: Kevin E. Spaulding, Douglas W. Couwenhoven
  • Patent number: 8094954
    Abstract: A binary conversion error value as to neighboring pixels stored in an error value storage portion is added to a pixel density of a subject pixel, which is read from an input image storage portion, at a ratio based on an error distribution matrix, so that a modified density is calculated. A determination is made as to whether the modified density is greater than or equal to a threshold value, and an output image is binarized based on the determination, and stored in an output image storage portion. An output density, which is a value of the output image for calculating the binary conversion error value, is set to a value corresponding to a print mode currently set. By subtracting the output density from the modified density, the binary conversion error value generated in the binarization process for the subject pixel is calculated.
    Type: Grant
    Filed: September 17, 2010
    Date of Patent: January 10, 2012
    Assignee: Brother Kogyo Kabushiki Kaisha
    Inventor: Yasunari Yoshida
  • Patent number: 8049930
    Abstract: A method is performed to hide a watermark in two halftone images or in a single halftone image. The halftone image contains information of the hidden watermark, and each pixel value of the halftone image is associated with a corresponding offset value. The offset value is determined according to a corresponding pixel value of the watermark and a corresponding pixel value of another halftone image. The offset value is used to compensate a corresponding input value and a corresponding original error value of the halftone image.
    Type: Grant
    Filed: September 15, 2008
    Date of Patent: November 1, 2011
    Assignee: National Taiwan University of Science and Technology
    Inventors: Jing-Ming Guo, Yun-Fu Liu
  • Patent number: 8018623
    Abstract: A method for multi-level error diffusion halftoning an input digital image to form an output digital image with reduced error diffusion texture contouring artifacts which includes modifying the input pixel values for a fraction of the input pixels using a periodic dither signal, where the fraction is a function of the texture artifact characteristics of the multi-level error diffusion halftoning process.
    Type: Grant
    Filed: February 29, 2008
    Date of Patent: September 13, 2011
    Assignee: Eastman Kodak Company
    Inventors: Douglas W. Couwenhoven, Kevin E. Spaulding
  • Patent number: 7982916
    Abstract: A method for multi-toning an input digital image having input pixels with two or more color channels to form an output digital image having modified output levels. The method includes determining modified output levels using a combined error signal formed from intermediate error signals for each color channel together with an error signal offset value, and adjusting the input levels for the nearby pixels responsive to weighted error signals.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: July 19, 2011
    Assignee: Eastman Kodak Company
    Inventors: Kevin E. Spaulding, Douglas W. Couwenhoven
  • Publication number: 20110170141
    Abstract: An image processing apparatus quantizes multi-level image data of n colors, where n?2, by performing an error diffusion processing. The image processing apparatus includes: a dot arrangement determining unit that determines either one of an essential dot count and an essential recording material amount when the multi-level image data of n colors is converted into multi-level image data of m colors, where n>m?1, by the error diffusion processing; and a color arrangement determining unit that performs the error diffusion processing on each color component of the multi-level image data of n colors, calculates either one of a dot count and a recording material amount for each color component, and determines an arrangement of either one of the dot count and the recording material amount for each color component within a range of a corresponding one of the essential dot count and the essential recording material amount determined by the dot arrangement determining unit.
    Type: Application
    Filed: September 14, 2009
    Publication date: July 14, 2011
    Inventors: Arata Yamaguchi, Hiroaki Sagae, Takashi Kimura, Masakazu Yoshida
  • Patent number: 7965418
    Abstract: Image processing apparatus and image processing method for formation of high quality image by high-speed error diffusion processing by execution of more complicated threshold condition processing in a simple manner. When error diffusion processing is performed on multivalued image data having plural density components and the result of processing is outputted, upon execution of error diffusion processing on a first density component among the plural density components, a threshold value used in the error diffusion processing is determined based on a density value of a second density component, then the error diffusion processing is performed on the first density component based on the determined threshold value, and the result of execution of the error diffusion processing is outputted.
    Type: Grant
    Filed: November 23, 2010
    Date of Patent: June 21, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akitoshi Yamada, Hiromitsu Hirabayashi, Masao Kato
  • Patent number: 7952764
    Abstract: What is provided are a novel system, method, and computer program product for hierarchical (telescopic) color error diffusion which effectively controls the dot distribution for both primary and secondary dot formation which covers the class of error diffusion that follow telescopic dot firing constraint principles. In one example embodiment, an input CMYK ink coverage is received. The input CMYK ink coverage is transformed into a CMYKRGB domain using a CMYK to CMYKRGB conversion. A weighted error value can be added to each color component of the CMYKRGB domain. The color components of the CMYKRGB domain are hierarchically grouped into a plurality of subgroups based on relative dot visibility. More visible subgroups are half-toned earlier to achieve maximum uniform dot distribution. Dots of specific color channels within subgroups are fired based on thresholding and a set of decision rules provided herein.
    Type: Grant
    Filed: February 5, 2008
    Date of Patent: May 31, 2011
    Assignee: Xerox Corporation
    Inventor: Zhen He
  • Patent number: 7933461
    Abstract: A filter for implementing Floyd Steinberg two-dimensional error diffusion algorithms allows high-speed processing of video and images. The filter is shown in direct form with proper bit precision with implementations that permit the filter to operate at high speed. Furthermore, a reduction in the gate count is achieved over the direct form. The results of static timing analysis obtained post synthesis are also summarized.
    Type: Grant
    Filed: October 14, 2009
    Date of Patent: April 26, 2011
    Assignee: Marvell International Ltd.
    Inventor: Bharat Pathak
  • Patent number: 7916350
    Abstract: What is disclosed is a novel system and method for minimizing visual artifacts, such as ROS skew and laserbeam bow, in a brick-layer halftone structure. The present method involves determining a line pattern from ROS skew and laserbeam bow profiles which traverses through successive halftone cells displacing pixels along scanlines in the process direction. The amount of displacement is varied as a function of the cross-process location as determined by the line pattern. Pixels along scanlines are shifted in a direction defined by the error profiles. In each halftone cell within which the line pattern traverses, extra pixels (empty pixel spaces created in the halftone cell by the shifting operation) are filled with lost pixels (pixels bumped from the halftone cell during the shifting operation) such that overall density of the halftone cell is maintained. The lost pixels are buffered such that lost pixels are preserved.
    Type: Grant
    Filed: April 15, 2008
    Date of Patent: March 29, 2011
    Assignee: Xerox Corporation
    Inventor: Hung M. Pham
  • Publication number: 20110069355
    Abstract: Image processing apparatus and image processing method for formation of high quality image by high-speed error diffusion processing by execution of more complicated threshold condition processing in a simple manner. When error diffusion processing is performed on multivalued image data having plural density components and the result of processing is outputted, upon execution of error diffusion processing on a first density component among the plural density components, a threshold value used in the error diffusion processing is determined based on a density value of a second density component, then the error diffusion processing is performed on the first density component based on the determined threshold value, and the result of execution of the error diffusion processing is outputted.
    Type: Application
    Filed: November 23, 2010
    Publication date: March 24, 2011
    Applicant: CANON KABUSHIKI KAISHA
    Inventors: AKITOSHI YAMADA, HIROMITSU HIRABAYASHI, MASAO KATO
  • Patent number: 7889394
    Abstract: An image processing apparatus for processing multilevel image data including values of respective color components includes an adding unit configured to add quantization errors to the respective values of the color components of a target pixel, an output determination unit configured to perform quantization to determine output values of the respective color components of the target pixel based on a combination of the values of the respective color components to which the quantization errors are added, and an error calculation unit configured to calculate quantization errors of the respective color components of the target pixel based on the output values of the respective color components and the values of the respective color components to which the quantization errors are added.
    Type: Grant
    Filed: May 7, 2007
    Date of Patent: February 15, 2011
    Assignee: Canon Kabushiki Kaisha
    Inventors: Osamu Iwasaki, Naoji Otsuka, Hitoshi Nishikori
  • Patent number: 7859723
    Abstract: Image processing apparatus and image processing method for formation of high quality image by high-speed error diffusion processing by execution of more complicated threshold condition processing in a simple manner. When error diffusion processing is performed on multivalued image data having plural density components and the result of processing is outputted, upon execution of error diffusion processing on a first density component among the plural density components, a threshold value used in the error diffusion processing is determined based on a density value of a second density component, then the error diffusion processing is performed on the first density component based on the determined threshold value, and the result of execution of the error diffusion processing is outputted.
    Type: Grant
    Filed: April 28, 2009
    Date of Patent: December 28, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Akitoshi Yamada, Hiromitsu Hirabayashi, Masao Kato
  • Patent number: 7855809
    Abstract: An image processing apparatus executes an error diffusion process to multivalue image data consisting of a plurality of density components. A first processor executes the error diffusion process by changing at least one of a quantization threshold value and a quantization diffusion coefficient which are used for the error diffusion process based on a value of the multivalue image data of the density components or a value calculated from the multivalue image data value. A second processor executes the error diffusion process by setting the quantization threshold value and the quantization diffusion coefficient which are used for the error diffusion process into fixed values. An error diffusion processing controller controls to execute the error diffusion process to at least one color among the density components by the first processor and execute the error diffusion process to other density components by the second processor.
    Type: Grant
    Filed: December 3, 2003
    Date of Patent: December 21, 2010
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masao Kato, Akitoshi Yamada, Mitsuhiro Ono
  • Patent number: 7826098
    Abstract: An isolation point counting section, an internal edge counting section, and a continuity detecting section are provided at a halftone dot internal character region signal generating section. The halftone dot internal character region signal generating section discriminates a character region in a halftone dot image based on the detection results of the isolation point counting value caused by the isolation point counting section, the internal edge count value caused by the internal edge counting section, and the presence or absence of continuity of the internal edges caused by the continuity detecting section by making best use of the fact that the halftone dot region and character region in the halftone dot image are completely reversed in their characteristics.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: November 2, 2010
    Assignee: Minolta Co., Ltd.
    Inventor: Hiroyuki Suzuki
  • Patent number: 7826097
    Abstract: A method for adjusting dot-gain for a halftone binary bitmap file comprises inputting a halftone binary bitmap file consisting of binary pixels (400) to an asymmetric digital filter (500). The binary pixels are filtered with the asymmetric digital filter and generates multi-level pixels (506). The multi-level pixel are compared to a preset level (408) and generates a binary pixel output (410). The binary pixel output is collected and forms an adjusted halftone binary bitmap file (270).
    Type: Grant
    Filed: May 29, 2007
    Date of Patent: November 2, 2010
    Assignee: Eastman Kodak Company
    Inventors: Kurt M. Sanger, Gustav J. Braun, Peter D. Burns
  • Publication number: 20100265548
    Abstract: An image processing apparatus, which performs an error diffusion on M-value image data with an error weight matrix into N-value image data, includes: a corrected-value calculating unit that calculates a corrected value by adding a first value and a second value to a pixel value corresponding to a processing-target color component of a pixel of interest, the first value being obtained by multiplying an error for each quantized pixel of the processing-target color component by the matrix, and the second value being obtained by multiplying an error for each quantized pixel of a different color component by the matrix; a quantizing unit that compares the corrected value with a quantization threshold, and outputs N-value image data; and an error diffusion unit that calculates an error at the pixel of interest by subtracting a quantization threshold from a value obtained by adding the first value to the pixel value.
    Type: Application
    Filed: April 14, 2010
    Publication date: October 21, 2010
    Inventors: Arata YAMAGUCHI, Hiroaki SAGAE, Takashi KIMURA, Masakazu YOSHIDA, Shigetaka SAKAKIBARA
  • Publication number: 20100202023
    Abstract: An image processing method suitable for a printer unit, includes an error diffusion halftoning process arranged for quantizing and diffusing each pixel of an image including a set of subtractive primary colours (C?, M?, Y?), in an image including a quantized printer image including a set of ink drops (DC, DM, DY, Dc, Dm) of respective ink channels to be printed. The method comprises the step of determining, for each pixel, an input variable value (S) representing a measure of solvent quantity that should be ejected by the printer unit for each pixel, the input variable value being computed on the basis of the value of a corresponding pixel of the image including the set of subtractive primary colours (C?, M?, Y?), and of inputting the determined input variable value (S) in the error diffusion halftoning process together with the values of the corresponding pixel. The invention further relates to the apparatus embodying the method.
    Type: Application
    Filed: September 3, 2007
    Publication date: August 12, 2010
    Inventors: Rosa Maria Figueras I Ventura, Ana Dimitrijevic, Kevin Fine, Serge Cattarinussi
  • Patent number: 7733531
    Abstract: An image processing apparatus includes: an image data acquiring unit that acquires image data formed of plural pixel data having an M-ary (M?3) gradation value; a grouping unit that divides the image data acquired into J (J?2) image data areas and sections the J image data areas into K (2?K?J) groups; a pixel data selecting unit that selects, for each of the image data areas forming the respective groups, predetermined pixel data out of pixel data included in the image data area; an N-arization processing unit that applies the N-arization (M>N?2) processing to the pixel data selected on the basis of a predetermined threshold value; and an error diffusing unit that diffuses a difference between a value of the selected pixel data and a value after the N-arization processing for the selected pixel data to pixel data not subjected to the N-arization processing, wherein the error diffusing unit diffuses the difference in directions different from one another in two or more groups of the K groups.
    Type: Grant
    Filed: January 17, 2006
    Date of Patent: June 8, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Toru Takahashi, Atsushi Oshima
  • Patent number: 7719720
    Abstract: Selecting a corresponding procedure of dithering according to a general pattern of gray levels of sub-pixels of each color of an input image. This will enable the input image to be displayed on a display with a lower bit depth.
    Type: Grant
    Filed: May 22, 2006
    Date of Patent: May 18, 2010
    Assignee: NOVATEK Microelectronics Corp.
    Inventors: Ming-Chang Liu, Rei-Hong Chang
  • Patent number: 7719718
    Abstract: A device and method is provided for breaking up undesirable patterns in vector error diffusion when the sum of inputs is near fraction values of the total input range. In the method, the value of the sum is calculated modulo the maximum input value. The mod value tendency to produce limit cycles is then determined for multiple planes in a manner similar to that for an individual plane. The threshold process for the vector calculation can then be modified to break up the cycles that occur in the combinations of the multiple colors. Typically, the largest of the individual plane modifications and the vector sum mod value is used for threshold modification. At least two different types of threshold modifications are possible: (1) random or psuedo-random noise address to the threshold; and (2) non-contiguous regions of threshold.
    Type: Grant
    Filed: March 13, 2007
    Date of Patent: May 18, 2010
    Assignee: Xerox Corporation
    Inventor: David Allen Mantell
  • Patent number: 7672013
    Abstract: Methods and apparatus are provided for electronically trapping a selected digital color image pixel. A plurality of pixels that surround the selected pixel are identified, a colorant value of each of the surrounding pixels is compared with a corresponding colorant value of the selected pixel, one of the surrounding pixels is identified to control trapping of the selected pixel, and the selected pixel is trapped based on a relationship between a colorant value of the selected pixel and a corresponding colorant value of the identified controlling pixel.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: March 2, 2010
    Assignee: Electroncics for Imaging, Inc.
    Inventors: Yigal Accad, Richard Falk, Mark Kelley
  • Patent number: RE42473
    Abstract: An adaptive halftoning method where the difference between a digital image and a filtered digital image is introduced into the system on a pixel by pixel basis is disclosed.
    Type: Grant
    Filed: August 30, 2007
    Date of Patent: June 21, 2011
    Assignee: Senshin Capital, LLC
    Inventors: Izrail S. Gorian, Jay E. Thornton, Richard A. Pineau