Patents by Inventor Raja Bala

Raja Bala has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20110052888
    Abstract: A document may include a non-magnetic substrate, a first colorant mixture printed as a first image upon the substrate, the first colorant mixture including a magnetic ink, and a second colorant mixture printed as a second image upon the substrate in substantially close spatial proximity to the printed first colorant mixture. The second colorant mixture may consist essentially of one or more non-magnetic inks and exhibit properties of both low visual contrast and high magnetic contrast against the first colorant mixture, such that the resultant printed substrate does not reveal the first image to the human eye, but will reveal the first image to a magnetic image reader.
    Type: Application
    Filed: August 25, 2009
    Publication date: March 3, 2011
    Applicant: XEROX CORPORATION
    Inventors: Reiner Eschbach, Martin S. Maltz, Raja Bala, Yonghui Zhao
  • Patent number: 7884964
    Abstract: Methods and systems in an image processing device for controlling colors that are located external to a gamut are disclosed. A plurality of color values can be automatically provided as input to said image processing device, wherein said image processing device is under a control of a particular dimensional order, typically a three-dimensional order, but alternatively can be a two-dimensional order. Next, an operation can be performed dynamically determining which color value among the plurality of color values has attained a gamut limit. Thereafter, the particular dimensional order can be automatically reduced, thereby providing improved control for colors that are located external to said gamut. The plurality of color values analyzed is generally associated with three colors—cyan, magenta, and yellow.
    Type: Grant
    Filed: August 5, 2003
    Date of Patent: February 8, 2011
    Assignee: Xerox Corporation
    Inventors: Martin S. Maltz, Raja Bala, Lalit K. Mestha
  • Patent number: 7869087
    Abstract: Methods and systems are presented for calibrating or characterizing a color printer or determining the color response of a color printer to combat spatial non-uniformity, in which color patches are printed on a test page according to an input matrix of input color in a printer-dependent-color space and the test page is measured to provide a corresponding output matrix of output color in a printer-independent-color space. Initial forward and inverse color transforms between the input and the output colors are generated based on the input and the output matrices. The output values are mapped to the input color space based on the initial inverse transform to form a feedback matrix, and spatial non-uniformities present in the printed test page are estimated according to noise values derived from the input matrix and the feedback matrix.
    Type: Grant
    Filed: March 31, 2007
    Date of Patent: January 11, 2011
    Assignee: Xerox Corporation
    Inventors: Shen-ge Wang, Raja Bala, Willey Huaili Wang
  • Patent number: 7864364
    Abstract: A color transformation method which accounts for colorant interactions includes establishing a plurality of tone reproduction curves (TRCs), for one or more of the color separations forming a digital image. Each TRC accounts for colorant interactions between a primary colorant with which the first color separation is to be rendered and at least one secondary colorant with which at least a second of the plurality of color separations is to be rendered. The TRCs include input values and their corresponding modified input values. In a given TRC, the input values of the second and optionally other color separations are fixed. For a pixel of the digital image having a given input values for the first and second color separation one or more of the TRCs are selected which bound the fixed input value for the second color separation and a modified input value is determined therefrom.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: January 4, 2011
    Assignee: Xerox Corporation
    Inventors: Yeqing Zhang, Robert P. Loce, Raja Bala
  • Patent number: 7852515
    Abstract: A watermark can be embedded in an image that has the property of being relatively indecipherable under normal light by including a distraction pattern, and yet remains decipherable under infrared illumination when viewed by a suitable infrared sensitive instrument. This infrared mark comprises, a substrate reflective to infrared radiation, a foreground colorant mixture printed as an image upon the substrate, a background colorant mixture and a distraction colorant mixture. A resultant collocated image rendered substrate suitably exposed to an infrared illumination, will yield a discernable image evident as a infrared mark to a suitable infrared sensitive device, but remain undecipherable under normal ambient light.
    Type: Grant
    Filed: June 5, 2007
    Date of Patent: December 14, 2010
    Assignee: Xerox Corporation
    Inventors: Reiner Eschbach, Farzin Blurfrushan, Raja Bala
  • Publication number: 20100302594
    Abstract: Systems and methods are described that facilitate real-time personalization of an electronic image by overlaying a text string on a planar surface of an object in the electronic image. A linear or affine transform is executed on a selected text string to position the text string in a reference rectangle or text box. A non-linear or projective transform is applied to the rectangular text box to project the box into a user-defined quadrilateral on the planar surface in the image. A page description language (PDL) file is generated and includes the transformed quadrilateral text box overlaid on the electronic image. At print-time, a database (e.g., a spreadsheet or the like) containing multiple text strings is read, once for each text string, and multiple images are printed. Each printed image has one of the text strings overlaid thereon, on the planar surface defined by the quadrilateral.
    Type: Application
    Filed: June 1, 2009
    Publication date: December 2, 2010
    Applicant: Xerox Corporation
    Inventors: Edward Chapman, Hengzhou Ding, Reiner Eschbach, Raja Bala
  • Patent number: 7835036
    Abstract: Identifying the substrate type of a target substrate before patterning by a marking engine produces an opportunity to adjust the marking engine. The adjustments can enable the marking engine to produce higher quality work. The target substrate's substrate type can be automatically identified by obtaining its characteristics and submitting them to a classifier. A spectrophotometer can measure a substrates reflectance spectrum, which is a good characteristic for use in classifying. Classifiers can be based on known distance or correlation measures.
    Type: Grant
    Filed: May 2, 2005
    Date of Patent: November 16, 2010
    Assignee: Xerox Corporation
    Inventors: Lalit K. Mestha, Raja Bala, Reiner Eschbach
  • Patent number: 7835033
    Abstract: This disclosure provides a method and system to generate device dependent color space representations for an image output device. The method and system are particularly applicable to a printing device, where gamut boundary separated profile methods are executed to map device in-gamut and device out-of-gamut colors.
    Type: Grant
    Filed: January 25, 2008
    Date of Patent: November 16, 2010
    Assignee: Xerox Corporation
    Inventors: Raja Bala, Martin S. Maltz, Lalit Keshav Mestha, Alvaro Enrique Gil
  • Publication number: 20100272355
    Abstract: What is disclosed is a novel system and method for performing spatial gamut mapping on a received input color image having a plurality of pixels. A standard gamut-mapping algorithm is applied to the input color image to produce a gamut-mapped color image. A difference is computed between a selected channel of the input color image and the gamut-mapped image to produce a difference image. A local measure of complexity is derived for a given pixel in the difference image. One or more parameter values of a spatial bilateral filter are obtained from a lookup table based on the computed local measure of complexity. The spatial bilateral filter is applied, using the obtained parameter values, to the current pixel of the difference image to produce a modified pixel in a modified difference image. Thereafter, a modified gamut-mapped color image is obtained from the modified difference image and the gamut-mapped color image.
    Type: Application
    Filed: April 24, 2009
    Publication date: October 28, 2010
    Applicant: Xerox Corporation
    Inventors: Vishal MONGA, Raja BALA, Michael BRANCIFORTE
  • Publication number: 20100265522
    Abstract: Systems and methods are provided for rendering tints of spot color objects or target colors between a spot color and a second color in image forming devices. In particular the systems and method provided allow for a sweep of a spot color to be rendered accurately, without discontinuities when transitioning from the tint to the solid spot color. The systems and method will prevent discontinuities even if the solid spot color has been modified by a user.
    Type: Application
    Filed: April 16, 2009
    Publication date: October 21, 2010
    Applicant: XEROX CORPORATION
    Inventors: Edul N. DALAL, Wencheng WU, Raja BALA
  • Publication number: 20100238508
    Abstract: A method and system is disclosed for characterizing a color scanner comprising generating a halftone-independent target of color patches, printing the target on a color hardcopy device, measuring the target to obtain device-independent color values, scanning the target to obtain scanner color values, and building a scanner profile that relates scanned color values to device-independent color values.
    Type: Application
    Filed: March 17, 2009
    Publication date: September 23, 2010
    Applicant: Xerox Corporation
    Inventors: Vishal Monga, Shen-Ge Wang, Raja Bala
  • Publication number: 20100239162
    Abstract: This disclosure provides methods, apparatus and systems for performing image processing regression for approximating multidimensional color transformation. According to an exemplary method, a shaping matrix is selected to minimize a cost function associated with a local linear regression representation of the color transformation.
    Type: Application
    Filed: March 18, 2009
    Publication date: September 23, 2010
    Applicant: Xerox Corporation
    Inventors: Vishal Monga, Raja Bala
  • Patent number: 7800785
    Abstract: The teachings as provided herein relate to a watermark embedded in an image, and methodology for same, that has the property of being relatively indecipherable under normal light, and yet decipherable under UV light. This fluorescent mark comprises a substrate containing optical brightening agents, and a first dot design printed as an image upon the substrate. The first dot design has as a characteristic, the property of strongly suppressing substrate fluorescence. A second dot design having a property of providing a differing level of substrate fluorescence suppression from that of the first dot design such that when rendered in close spatial proximity with the first dot design image print, the resultant image rendered substrate suitably exposed to an ultra-violet light source, will yield a discernable image evident as a fluorescent mark.
    Type: Grant
    Filed: May 29, 2007
    Date of Patent: September 21, 2010
    Assignee: Xerox Corporation
    Inventors: Raja Bala, Reiner Eschbach, Shen-Ge Wang, Yonghui Zhao
  • Publication number: 20100231980
    Abstract: A method for defining a gloss effect in a printed document includes printing a document region with first and second colorant combinations. The first colorant combination defines a first colorant stack height and said second colorant combination defines a second colorant stack height that differs from the first colorant stack height. As such, the document region has a first appearance when viewed straight-on and a second appearance when viewed at an angle. In one example, the first colorant combination is black (K) colorant that results in a one-level stack height and the second colorant combination is cyan, magenta, and yellow (CMY) colorants that result in a three-level stack height. In another example, the second colorant combination can be cyan, magenta, yellow and black (CMYK) colorants that define a four-level stack height.
    Type: Application
    Filed: March 16, 2009
    Publication date: September 16, 2010
    Applicant: XEROX CORPORATION
    Inventors: Edward Chapman, Reiner Eschbach, Shen-Ge Wang, Raja Bala
  • Publication number: 20100220926
    Abstract: A dimensionality reduction method and system for efficient color transform compression is disclosed. A multi-dimensional color transform with an n-dimensional input color space can be received. A projection operator can be derived and applied to the n-dimensional input color space to form a k-dimensional input color space. A functional approximation can be designed to the n-dimensional input color space and can be evaluated on the k-dimensional input color space to form an m-dimensional output color space. The projection operator and the approximation function can be combined to form a compressed transform by mapping the n-dimensional input color space to m-dimensional output color space. Such an approach provides a significant reduction in size of the color profile with respect to storage and speeds-up real-time computation.
    Type: Application
    Filed: March 2, 2009
    Publication date: September 2, 2010
    Inventors: Vishal Monga, Raja Bala
  • Patent number: 7768671
    Abstract: An image characterized by an original image gamut is received in an imaging device characterized by a device gamut. The original image gamut is enhanced to a first set of modified color values that occupy a greater fraction of the device gamut than the original image gamut. The modified color values of each pixel are mapped to new color values within the device gamut.
    Type: Grant
    Filed: September 18, 2006
    Date of Patent: August 3, 2010
    Assignee: Xerox Corporation
    Inventors: Raja Bala, Michael Branciforte, Reiner Eschbach
  • Patent number: 7768682
    Abstract: A multi-dimensional printer profile look-up table for color correction is generated. First, an initial estimate for a black (K) component in a four-color color space for received color signals in the device independent color space is generated by using a three-dimensional parametric function. Next, initial estimates for the three non-black color components of the four-color color space are generated from the generated initial estimate for the black (K) component and the received color signals. Then, a printer profile including a map that maps the device independent color space to the four-color color space is generated using the generated initial estimates for the black (K) and the three non-black color components in the four-color color space.
    Type: Grant
    Filed: January 22, 2008
    Date of Patent: August 3, 2010
    Assignee: Xerox Corporation
    Inventors: Lalit Keshav Mestha, Yao Rong Wang, Alvaro Enrique Gil, Martin S. Maltz, Raja Bala
  • Publication number: 20100188672
    Abstract: An image processing apparatus, program product, and method determine an achievable gamut achievable by the imaging engine or engines for all spatial locations of an output image, or all utilized print engines. A reference gamut is calculated which is any gamut containing the achievable gamut. A gamut mapping is used to map gamuts from the mean gamut to the achievable gamut, and a set of transformations is calculated for each of a set of input colors to a set of target colors selected from colors in the achievable gamut. Values for a received digital image are transformed for each image pixel or clusters of pixels based on the calculated set of transformations. Output images are generated based on the transformed values.
    Type: Application
    Filed: January 26, 2009
    Publication date: July 29, 2010
    Applicant: Xerox Corporation
    Inventors: Edgar Bernal, Robert P. Loce, Raja Bala
  • Patent number: 7764403
    Abstract: Extended colorant sets are used to hide data or provide a watermark in printed images. Extended set colorants are colorants other than, and in addition to, the standard or common subtractive primary colorants: cyan, magenta, yellow and/or black. Where the extended colorant set supports a plurality of colorant recipes for rendering a given color, watermark data is used to select a colorant recipe from the plurality. As the watermark data to be encoded in the image changes state with image position, alternate colorant recipes or colorant selection functions are selected. The image is rendered based on the alternate colorant recipe selections. Watermark information is encoded in the colorant recipe or colorant selection function selection. Use of the extended colorant sets allows information to be encoded even in portions of an image having colors that do not include a neutral component.
    Type: Grant
    Filed: December 6, 2006
    Date of Patent: July 27, 2010
    Assignee: Xerox Corporation
    Inventors: Robert P. Loce, Raja Bala, Karen M. Braun
  • Publication number: 20100182649
    Abstract: A model-based halftone independent method for characterizing a printer equipped with a plural of halftone screens comprises: printing a target set of basic patches comprised of a fundamental binary pattern independent of a halftone screen; measuring true color printer response from the target set; modeling a halftone independent characterization of the printer with the mathematical transformation using the measured response; modeling a first halftone dependent characterization of the printer with the mathematical transformer to generate a first predicted result using a selected halftone screen; comparing a measured response of the printer using the halftone screen with the predicted result to define a correction factor corresponding to the halftone screen; and modeling a halftone dependent characterization of the printer using a predicted response of the fundamental binary pattern and the correction factor.
    Type: Application
    Filed: January 21, 2009
    Publication date: July 22, 2010
    Applicant: Xerox Corporation
    Inventors: Vishal Monga, Shen-Ge Wang, Raja Bala