WO1998052347A1 - Arrangement for efficient characterization of printing devices and method therefor - Google Patents
Arrangement for efficient characterization of printing devices and method therefor Download PDFInfo
- Publication number
- WO1998052347A1 WO1998052347A1 PCT/US1998/007268 US9807268W WO9852347A1 WO 1998052347 A1 WO1998052347 A1 WO 1998052347A1 US 9807268 W US9807268 W US 9807268W WO 9852347 A1 WO9852347 A1 WO 9852347A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- color
- halftone
- values
- color values
- bitmaps
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 86
- 238000007639 printing Methods 0.000 title claims abstract description 48
- 238000012512 characterization method Methods 0.000 title description 4
- 238000000926 separation method Methods 0.000 claims abstract description 42
- 238000012360 testing method Methods 0.000 claims abstract description 39
- 230000008569 process Effects 0.000 claims abstract description 38
- 239000003086 colorant Substances 0.000 claims description 47
- 230000001419 dependent effect Effects 0.000 claims description 2
- 238000005259 measurement Methods 0.000 description 18
- 230000009466 transformation Effects 0.000 description 9
- 238000002156 mixing Methods 0.000 description 3
- 238000009877 rendering Methods 0.000 description 3
- 238000012216 screening Methods 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 238000012935 Averaging Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000009499 grossing Methods 0.000 description 2
- 230000001788 irregular Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 238000003491 array Methods 0.000 description 1
- 238000004364 calculation method Methods 0.000 description 1
- 238000009125 cardiac resynchronization therapy Methods 0.000 description 1
- 238000013500 data storage Methods 0.000 description 1
- 238000001739 density measurement Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 238000012804 iterative process Methods 0.000 description 1
- 238000007648 laser printing Methods 0.000 description 1
- 238000007726 management method Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 238000000053 physical method Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000002250 progressing effect Effects 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N1/00—Scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission; Details thereof
- H04N1/46—Colour picture communication systems
- H04N1/56—Processing of colour picture signals
- H04N1/60—Colour correction or control
- H04N1/603—Colour correction or control controlled by characteristics of the picture signal generator or the picture reproducer
- H04N1/6033—Colour correction or control controlled by characteristics of the picture signal generator or the picture reproducer using test pattern analysis
Definitions
- the present invention relates generally to the practice of color reproduction. More particularly, the present invention relates to the practice of characterizing printing devices.
- Color printing processes involve producing full- color images on a medium, such as paper or film, through the use of colorants.
- Colorants are formed on media by various techniques, including halftone printing, dye diffusion, ink jet, thermal wax, and color laser printing.
- typical halftone printing processes produce colors as arrays of dots of various colorants.
- an original image is scanned through color filters to form a set of continuous-tone color separations.
- Each of the color separations represents intensities of one of the separated colors, such as magenta, at a plurality of pixel locations within the original image.
- the continuous-tone color separations are processed using a halftone screening system to produce a set of halftone color separations in the form of bitmaps.
- color separation bitmaps of this type are used to form halftone printing plates or to control a halftone printing mechanism, such as a thermal mass-transfer device.
- the addressable units addressed by the color separation bitmaps are imaged on a printing substrate by formation of device spots carrying colorants that correspond to the separated colors .
- the device spots are typically sized somewhat larger than the addressable units in order to provide a degree of partial overlap that prevents the appearance of gaps between adjacent spots in areas of solid color.
- the device spots specified by each color separation bitmap are deposited in superposition with one another in substantial registration. The human eye integrates the superimposed colors of the device spots to form a representation of the original continuous-tone image.
- the accuracy of color rendering through typical halftone printing processes is increased by modeling the printer to a device-independent color space.
- Some types of device-independent color modeling techniques attempt to calibrate devices and data in terms of a device-independent color space, such as Commission Internationale de L'Eclairage (CIE) 1931 XYZ tristimulus space-coordinate values.
- CIE Commission Internationale de L'Eclairage
- PostScript and ColorSync provide a fixed framework that defines the processing for converting color specifications from the device-independent color space into an index color space and from the index color space into a device-dependent coordinate system.
- Device characterization compatible with such frameworks for some classes of printing devices have typically required empirical models that incorporate multi- dimensional lookup tables built from measurements of a large number of printed samples, generally on the order of 500 to 3000, that span the device gamut.
- one color rendering dictionary (CRD) generation technique requires measurement of a minimum of 512 samples spanning the device gamut (all combinations of each of eight RGB levels) .
- the sample data are typically obtained through time-consuming and tedious manual means or through use of an expensive automated apparatus .
- Some printing device models such as certain models of halftone printers, use the spot diameter of the device as a parameter. It is often assumed that the spot diameter is available either through a priori knowledge or physical measurements. However, some halftone printing devices produce irregular spots or are incapable of producing isolated device spots. These technical limitations make it difficult to measure the spot diameter.
- One aspect of the present invention is directed to an arrangement and method for modeling the colorimetric response of a printing device.
- the method comprises: obtaining a set of color values from each of a limited number of test patches, the number of test patches being substantially less than a number of test patches necessary to adequately sample a full range of realizable color combinations; constructing a halftone printer model using at least one device spot size parameter, the sets of color values, and a set of addressable units corresponding to device spot locations on a medium, each of the addressable units having an area that is less than an area of a device spot; generating a set of color separations representing a page of color samples spanning said full range and, from the set of color separations, a set of bitmaps; applying the halftone printer model to produce a digital representation of the page of color samples in a device-independent color space from the set of bitmaps; and generating a device profile that characterizes the halftone printing process as a function of the digital representation.
- Various arrangements to implement the method are disclosed.
- Another aspect of the present invention is directed to a data storage medium storing a computer- executable program that, when executed, performs steps related to those set forth above for characterizing a halftone printing process.
- These computer-executable steps include : obtaining a set of color values from each of a limited number of test patches, the number of test patches being substantially less than a number of test patches necessary to adequately sample a full range of realizable color combinations; constructing a halftone printer model using at least one device spot size parameter, the sets of color values, and a set of addressable units corresponding to device spot locations on a medium, each of the addressable units having an area that is less than an area of a device spot; generating a set of color separations representing a page of color samples spanning said full range and, from the set of color separations, a set of bitmaps; applying the halftone printer model to produce a digital representation of the page of color samples in a device-independent color space from the set of bitmaps; and generating a device profile that characterize
- FIG. 1 illustrates a system for characterizing a halftone printer device according to one embodiment of the present invention
- FIG. 2 is a diagram illustrating a plurality of regions produced in an addressable unit by a multi-color, halftone output according to one embodiment of the present invention
- FIGS. 3A-3B comprise a flow chart representing a process for characterizing a halftone printer device according to one embodiment of the present invention
- FIG. 4 is a flow chart representing a process for estimating a device spot size according to another aspect of the present invention that may be used in connection with the system of FIG . 1 .
- the present invention is applicable to color reproduction systems in which it is desirable to characterize printing devices using analytic device modeling techniques .
- the present invention has been found to be particularly advantageous for use in connection with the characterization of halftone printers.
- a halftone printer uses a large number of parameters to represent the various color combinations and other related variables. Characterizing a halftone printer using such models often requires hundreds or thousands of measurements of test patches .
- a halftone printer is modeled with a small number of parameters, including the size of a device spot and color values for each color that may be obtained by combining colorants in various combinations.
- sixteen primaries and overprints are obtained by combining the four colors in various combinations.
- a four-color halftone printer model includes, in this embodiment, only sixteen parameters, as represented by the combinations of the four colors, plus one parameter for the size of a device spot.
- FIG. 1 illustrates one example of a system according to the present invention configured to model a printing device 14.
- a computer arrangement 10 appropriately programmed, is connected to the printing device 14, for example, a laser printer, an ink jet printer, a dye diffusion device, or other halftone printer.
- the computer arrangement 10 may be implemented, for example, as a conventional Apple computer or IBM- compatible computer, or as a group of computers.
- the computer arrangement 10 uses a printer model 16 to generate a device profile 18, such as a PostScript color rendering dictionary (CRD) or a ColorSync profile, that characterizes the printing device 14.
- CCD PostScript color rendering dictionary
- ColorSync profile that characterizes the printing device 14.
- the main components of the device profile 18 are a multi-dimensional lookup table, or render table 20, and two sets of transformation procedures 22 and 24.
- the first set of transformation procedures 22 transforms a set of coordinates from a device- independent color space, such as the XYZ color space, to an index space, for example, a calibrated RGB color space.
- the index space is selected to facilitate interpolation while using the render table 20.
- the render table 20 is used to convert coordinates in the index space to an encoded device color space.
- the second set of transformation procedures 24 transforms the encoded device color space coordinates into the final device color coordinates in a device color space.
- FIGS. 3A-3B comprise a flow chart illustrating a process 100 in which the computer arrangement 10 of FIG. 1 is used in a color reproduction process according to one method embodiment of the present invention.
- the steps depicted in FIGS. 3A-3B can be executed, for example, by the computer arrangement 10 in connection with a computer- executable program.
- a block 102 of FIG. 3A depicts the computer obtaining generally parameters for the device model, including the device spot size and the XYZ values for the ink and medium combination's primaries and overprints, and the sets of procedures 22 and 24.
- the computer arrangement 10 provides test image data to the printing device 14 of FIG. 1.
- the printing device 14 prints a test target, which consists of a number of test patches representing the primaries and overprints of the printer.
- a test target produced by a bi-level, four- color printer would include the four primaries ⁇ e . g.
- the computer arrangement 10 receives color measurements of the test target from a color- measuring instrument (not illustrated) and provides these measurements to a four-color halftone printer model, as depicted at a block 108.
- the color-measuring instrument can be implemented, for example, using a spectrophotometer, which measures the apparent reflectance of light as a function of wavelength, or a colorimeter, which typically determines a set of tristimulus values of a color. From the color measurements, the computer arrangement 10 derives a set of values in a reference color space, such as the XYZ coordinate system.
- estimates of the device spot size may be specified or obtained using conventional techniques, such as microscopic inspection of test samples, density measurements of an appropriate test target, or as described below in connection with FIG. 4.
- the set of procedures 24 allows the render table to produce values that are more linear with respect to the actual device colorants.
- the linearized values produced from the render table 20 are subsequently transformed through 1-D lookup tables to produce the final device coordinates.
- the 1-D lookup tables are generated by linearizing a set of color measurements of color patch sequences known as step wedges.
- the set of procedures 24 can be defined as identity transforms. In this case, the final device coordinates are obtained directly from the render table 20.
- the computer arrangement 10 applies the halftone screening system characterizing the halftone process to each continuous-tone color separation to obtain a corresponding halftone color separation in the form of a bitmap .
- the bitmaps thus generated determine where the device spots would be placed if the page were printed.
- the computer then applies the halftone printer model (16 of FIG. 1) to the bitmaps to produce a digital representation of the page of color-spanning samples in a device-independent color space, e . g. , XYZ space.
- the computer arrangement 10 identifies the locations of the device spots 52 of FIG. 2 with respect to each of the addressable units 48 of the page based on the locations specified in the halftone bitmaps.
- the device spots 52 are centered on centers of the addressable units 48.
- Each device spot 52 is assigned the color corresponding to the particular bitmap that addressed it. For example, if a particular device spot 52 is addressed by the bitmap for the yellow color separation, the device spot 52 is assigned the color yellow.
- This process is depicted at a block 114a.
- the computer divides each of the addressable units 48 into a plurality of addressable subunits 52 at a block 114b in order to approximate the areas of the regions 30-42.
- the computer arrangement 10 counts, for each of the 2 N different colors produced by combining the N colorants and each of the addressable units 48, the subunits 54 in which the respective color is formed in the regions 30-42 by the device spots 52.
- this approximation process may be simplified by centering the device spots 42 on corners of the addressable units 48 rather than on the centers of the addressable units 48. By centering the device spots on the corners of the addressable units, the regions 30-42 can be determined using a lesser number of adjacently formed device spots 52.
- the computer arrangement 10 For each of the addressable units 48 and for each of the 2 N different colors, the computer arrangement 10 then divides the number of subunits 54 in which the color is formed by the total number of subunits, as depicted at a block 114d. In this manner, the computer arrangement 10 obtains fractional values for the 2 N different colors formed in the regions 30-42 in each of the addressable units 48. Each fractional value thus obtained approximates the area of the region 30-42 in which the color is formed as a fraction of the overall area of the addressable unit 48. The accuracy of this approximation method increases as the number of subunits 54 increases.
- Xi represents the tristimulus X component value measured for one of the 2 N different colors
- Y x represents the tristimulus Y component value measured for one of the 2 N different colors
- Z ⁇ represents the tristimulus Z component value measured for one of the 2 N different colors.
- a block 116 in which the computer arrangement 10 generates a measurements table containing index color space values, for example, calibrated RGB color values , indexed by device coordinates .
- the computer integrates device-independent page values within each continuous-tone separation sample. A band around the edges of each patch is excluded from the integration to minimize spatial dependencies resulting from the halftoning process.
- the computer arrangement 10 converts integrated device- independent values into the index space using the transformation defined by the set of procedures 22 and stores the index color space values in the measurements table .
- the computer arrangement 10 then generates the render table 20 at a block 118 by inverting the measurements table to generate a table of device coordinates indexed by, for example, calibrated RGB values. For each set of desired calibrated RGB indices, computer arrangement 10 searches the measurements table for the index color space values closest to the desired values. The computer arrangement 10 uses the device coordinates corresponding to the closest values as the entry in the render table 20. Conventional interpolation techniques may be used to refine the device coordinate values. After the device coordinates are computed for the entries in the render table 20, the computer arrangement 10 optionally applies a smoothing filter, such as a simple triangle kernel, to the render table 20 at a block 120. Smoothing the table reduces the likelihood of discontinuities in printed color gradients.
- a smoothing filter such as a simple triangle kernel
- the computer arrangement 10 then writes the device profile 18, which includes, for example, the sets of transformation functions 22 and 24 and a hexadecimal representation of the render table 20, to a data file, as depicted at a block 122.
- the data file may be written as an ASCII file in a PostScript format.
- the device profile 18 generated above is used to reproduce a color image accurately on the printing device 14.
- an image file (not illustrated) representing a color image in a reference color space, such as the XYZ color space, is stored in the computer arrangement 10.
- the computer arrangement 10 transforms the coordinates in the reference color space into an index color space, such as a calibrated RGB color space, using the set of procedures 22.
- the computer indexes the render table 20 by the index color space coordinates and retrieves entries from the render table 20. These entries represent the color in an encoded device color space specific to the printing device 14.
- the computer arrangement 10 uses the set of transformation procedures 24 as discussed previously, the computer arrangement 10 then transforms the encoded device color space coordinates into final device color space coordinates used by the printing device 14. Assuming the set of procedures 24 is defined as identity transforms, the render table 20 itself produces the final device color space coordinates. The computer arrangement 10 sends the final device color space coordinates to the printing device 14, which produces the color on the medium.
- the halftone printer model described above in connection with FIGS. 1-3 uses the device spot diameter as a parameter. While the device spot diameter may be specified or measured using conventional techniques, technical limitations of a typical halftone printer may make it difficult to determine the device spot diameter accurately. For example, some halftone printers print irregular spots or are unable to print an isolated device spot .
- FIG. 4 is a flow chart representing one example method 200 in which the system of FIG. 1 estimates the device spot diameter using an iterated printer model according to another aspect of the present invention.
- the method depicted in FIG. 4 can be executed, for example, by the computer arrangement 10 in connection with a computer- executable program.
- a block 210 depicts the computer arrangement 10 producing halftone bitmaps generally.
- the computer arrangement 10 generates a set of continuous-tone color separations, as depicted at a block 212.
- the continuous-tone color separations produce the color patches comprising the test target addressed in connection with FIGS. 3A-3B and additional patches that form a step wedge for each colorant.
- Each step wedge contains a sequence of color samples progressing from white to complete saturation of a colorant. For example, the color samples in a cyan step wedge progress from white to solid cyan, with intermediate steps representing increasing proportions of cyan.
- the number of additional test patches used depends on the application and on the desired accuracy. In certain applications in which especially high accuracy is desired, the computer arrangement 10 estimates a different spot diameter for each color separation. In applications of this type, four additional test patches for each color separation, evenly spaced in value, are typically more than adequate. In other types of applications in which such accuracy is not required, however, one diameter estimate for all color separations suffices. In applications of this type, fewer additional test patches are sufficient.
- the additional test patches may be selected from a single separation color or from multiple separation colors.
- the additional test patches are typically chosen from a single separation color. In certain applications, however, the printing of multiple colorants at one location produces a significantly different spot diameter than the printing of one colorant. In such applications, test patches that represent midtones of one separation color over solids of one or more additional separation colors may be used to improve the accuracy of the estimation process.
- the computer arrangement 10 applies the halftone process to be modeled to the continuous-tone color separations to obtain halftone separation bitmaps.
- the computer arrangement 10 applies the halftone screening system characterizing the halftone process to each continuous-tone separation in the form of a bitmap. The bitmaps thus generated determine where the device spots are placed when the page is printed.
- a block 202 depicts the computer arrangement 10 generating model parameters generally.
- the computer arrangement 10 causes the printing device 14, illustrated as a halftone printer, to produce a test target using the device spot locations specified by the halftone bitmaps. This process is depicted at a block 204.
- Flow then proceeds to a block 206, at which the computer arrangement 10 receives device-independent color values of the test target from a color-measuring instrument, such as a spectrophotometer or a colorimeter.
- a color-measuring instrument such as a spectrophotometer or a colorimeter.
- the computer arrangement 10 provides these measurements as parameters to the printer model (16 of FIG. 1) .
- the computer arrangement 10 does not initially determine a precise value of the device spot diameter. Instead, the computer arrangement 10 selects an initial estimate of the device spot diameter based on, for example, technical specifications. The value of the initial estimate is not critical, however, as it is refined through an iterative process as described below.
- the computer arrangement 10 receives the colorimetric measurements of the step wedge patches from the test target. With the initial estimate of the device spot diameter and the halftone separation bitmaps, the computer arrangement 10 applies the printer model 16 iteratively as depicted generally at a block 222 to determine the value of the device spot diameter that yields the most accurate predictions of the colorimetric measurements obtained at the block 220.
- the iterative application of the printer model 16 is based on a conventional search technique, such as the method disclosed in Brent, "Algorithms for Minimization without Derivatives," chapter 5. This method, known as Brent's method, uses inverse parabolic interpolation to find the minimum of a function in one dimension. In the example method 200 of FIG.
- the computer arrangement 10 determines the minimum mean squared error between the measured and predicted colorimetric values by varying the spot diameter. To determine the minimum mean squared error, the computer arrangement 10 predicts the colorimetric values of the test patches using the printer model 16 with the initial estimate of the device spot diameter, as depicted at a block 224. At a block 226, the computer arrangement 10 compares these estimates to the colorimetric values obtained at the block 220.
- the computer arrangement 10 adjusts the spot size estimate based on the error or difference between the estimated colorimetric values and the measured colorimetric values, as depicted at a block 228.
- the process depicted at the block 222 is repeated until the mean squared error between the predicted and measured colorimetric values is minimized.
- the device spot diameter estimate that yields the minimum mean squared error is then used as the device spot diameter parameter in connection with the system addressed above in connection with FIG. 1.
- the printer model 16 may be simplified when estimating the spot diameter, to reduce the computational requirements for each iteration of the process depicted at the block 222. If the colorimetric measurements are restricted to L * , for example, only the CIE Y values are predicted instead of X, Y, and Z values. Furthermore, if a test patch includes only one colorant, then a two-color model (paper and one colorant) may be used instead of the full 2 N -color model
Abstract
Description
Claims
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE69806154T DE69806154T2 (en) | 1997-05-14 | 1998-04-07 | ARRANGEMENT FOR EFFICIENT CHARACTERIZATION OF PRINTING DEVICES AND METHOD THEREFOR |
EP98918099A EP0981897B1 (en) | 1997-05-14 | 1998-04-07 | Arrangement for efficient characterization of printing devices and method therefor |
AU71088/98A AU7108898A (en) | 1997-05-14 | 1998-04-07 | Arrangement for efficient characterization of printing devices and method therefor |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US08/856,371 US6072589A (en) | 1997-05-14 | 1997-05-14 | Arrangement for efficient characterization of printing devices and method therefor |
US08/856,371 | 1997-05-14 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1998052347A1 true WO1998052347A1 (en) | 1998-11-19 |
Family
ID=25323443
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1998/007268 WO1998052347A1 (en) | 1997-05-14 | 1998-04-07 | Arrangement for efficient characterization of printing devices and method therefor |
Country Status (5)
Country | Link |
---|---|
US (1) | US6072589A (en) |
EP (1) | EP0981897B1 (en) |
AU (1) | AU7108898A (en) |
DE (1) | DE69806154T2 (en) |
WO (1) | WO1998052347A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1080892A2 (en) † | 1999-09-06 | 2001-03-07 | Komori Corporation | Color management method and apparatus for printing press |
EP1026893A3 (en) * | 1999-01-19 | 2001-11-21 | Xerox Corporation | Distributed digital image processing system |
EP2456623A1 (en) * | 2009-07-23 | 2012-05-30 | Hewlett Packard Development Company, L.P. | Accurate printing of a target colour |
Families Citing this family (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7057765B1 (en) | 1999-05-28 | 2006-06-06 | Eastman Kodak Company | Constrained multi-dimensional color transformation |
US6559975B1 (en) * | 1999-06-15 | 2003-05-06 | Microsoft Corporation | Full-color to a spot-color image converter |
JP2001197323A (en) * | 2000-01-13 | 2001-07-19 | Fuji Photo Film Co Ltd | Method an device for preparing profile |
US20010038459A1 (en) * | 2000-04-10 | 2001-11-08 | Marc Mahy | Method for optimising the colour target for a printer model |
US6930790B1 (en) * | 2000-05-01 | 2005-08-16 | Adobe Systems Incorporated | Color rendering dictionary for testing color conversion |
US6956966B2 (en) * | 2001-04-03 | 2005-10-18 | Electronics For Imaging, Inc. | Method and apparatus for automated image correction for digital image acquisition |
US7206100B2 (en) * | 2001-07-02 | 2007-04-17 | Canon Kabushiki Kaisha | Image processing method and apparatus |
US7209245B2 (en) * | 2001-09-20 | 2007-04-24 | Sharp Laboratories Of America, Inc. | Printing systems, softwares, and methods for user characterization of unknown printer media |
EP1522185A1 (en) * | 2002-07-10 | 2005-04-13 | Agfa-Gevaert | System and method for reproducing colors on a printing device |
US7256912B2 (en) * | 2003-06-25 | 2007-08-14 | Sharp Laboratories Of America, Inc | Adaptive generation of perceptually uniform samples for printer characterization |
US7688486B2 (en) * | 2004-04-30 | 2010-03-30 | Electronics For Imaging, Inc. | Methods and apparatus for profiling color output devices |
US7656414B2 (en) * | 2006-04-06 | 2010-02-02 | Kabushiki Kaisha Toshiba | System and method for determination of gray for CIE color conversion using chromaticity |
US7738140B2 (en) * | 2006-08-21 | 2010-06-15 | Xerox Corporation | System and method for automated spot color editor |
US8134740B2 (en) * | 2006-08-21 | 2012-03-13 | Xerox Corporation | Spot color controls and method |
AU2009251147B2 (en) * | 2009-12-23 | 2012-09-06 | Canon Kabushiki Kaisha | Dynamic printer modelling for output checking |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0456832A1 (en) * | 1989-12-05 | 1991-11-21 | Shaken Co., Ltd. | Method and apparatus for color image processing |
WO1996008916A1 (en) * | 1994-09-13 | 1996-03-21 | Apple Computer, Inc. | Method and system for analytic generation of multidimensional color lookup tables |
US5526140A (en) * | 1995-03-03 | 1996-06-11 | Minnesota Mining And Manufacturing Company | Emulation of a halftone printed image on a continuous-tone device |
Family Cites Families (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5438921B2 (en) * | 1974-05-31 | 1979-11-24 | ||
US4500919A (en) * | 1982-05-04 | 1985-02-19 | Massachusetts Institute Of Technology | Color reproduction system |
DE3332791C1 (en) * | 1983-09-10 | 1985-02-28 | Dr.-Ing. Rudolf Hell Gmbh, 2300 Kiel | Device for color image control on a color monitor |
US4769696A (en) * | 1986-05-01 | 1988-09-06 | Toppan Printing Co., Ltd. | Scanner set-up simulation apparatus |
US4958220A (en) * | 1988-12-27 | 1990-09-18 | Eastman Kodak Company | Color imaging apparatus producing visually matched displays of perceptually distinct reproduced images |
US5339176A (en) * | 1990-02-05 | 1994-08-16 | Scitex Corporation Ltd. | Apparatus and method for color calibration |
US5818960A (en) * | 1991-06-18 | 1998-10-06 | Eastman Kodak Company | Characterization calibration |
US5739928A (en) * | 1991-09-12 | 1998-04-14 | Eastman Kodak Company | Technique particularly suited for use in a print preview function for adapting CRT colorimetry to ambient lighting conditions |
US5317425A (en) * | 1992-02-10 | 1994-05-31 | Eastman Kodak Company | Technique for use in conjunction with an imaging system for providing an appearance match between two images and for calibrating the system thereto |
US5296947A (en) * | 1992-10-06 | 1994-03-22 | Cactus | System for softproofing a color reproduction |
US5473439A (en) * | 1992-10-23 | 1995-12-05 | At&T Corp. | Model-based halftoning of color images |
US5469267A (en) * | 1994-04-08 | 1995-11-21 | The University Of Rochester | Halftone correction system |
US5854882A (en) * | 1994-04-08 | 1998-12-29 | The University Of Rochester | Halftone correction systems |
EP0763928B1 (en) * | 1995-09-15 | 2001-10-10 | Agfa-Gevaert N.V. | Colour separation method and apparatus for same |
US5649073A (en) * | 1995-12-28 | 1997-07-15 | Xerox Corporation | Automatic calibration of halftones |
US5822451A (en) * | 1996-06-05 | 1998-10-13 | Eastman Kodak Company | Method for halftoning a multi-channel digital color image |
US5920682A (en) * | 1996-09-20 | 1999-07-06 | Seiko Epson Corporation | Multiple layer cluster dither matrix for reducing artifacts in printed images |
US5933578A (en) * | 1997-04-08 | 1999-08-03 | Barco Graphics, N.V. | Method and device for determining the color appearance of color overprints |
US5748330A (en) * | 1997-05-05 | 1998-05-05 | Xerox Corporation | Method of calibrating a digital printer using component test patches and the yule-nielsen equation |
-
1997
- 1997-05-14 US US08/856,371 patent/US6072589A/en not_active Expired - Lifetime
-
1998
- 1998-04-07 AU AU71088/98A patent/AU7108898A/en not_active Abandoned
- 1998-04-07 EP EP98918099A patent/EP0981897B1/en not_active Expired - Lifetime
- 1998-04-07 DE DE69806154T patent/DE69806154T2/en not_active Expired - Lifetime
- 1998-04-07 WO PCT/US1998/007268 patent/WO1998052347A1/en active IP Right Grant
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0456832A1 (en) * | 1989-12-05 | 1991-11-21 | Shaken Co., Ltd. | Method and apparatus for color image processing |
WO1996008916A1 (en) * | 1994-09-13 | 1996-03-21 | Apple Computer, Inc. | Method and system for analytic generation of multidimensional color lookup tables |
US5526140A (en) * | 1995-03-03 | 1996-06-11 | Minnesota Mining And Manufacturing Company | Emulation of a halftone printed image on a continuous-tone device |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1026893A3 (en) * | 1999-01-19 | 2001-11-21 | Xerox Corporation | Distributed digital image processing system |
EP1080892A2 (en) † | 1999-09-06 | 2001-03-07 | Komori Corporation | Color management method and apparatus for printing press |
EP1080892B2 (en) † | 1999-09-06 | 2009-06-24 | Komori Corporation | Color management method and apparatus for printing press |
EP2456623A1 (en) * | 2009-07-23 | 2012-05-30 | Hewlett Packard Development Company, L.P. | Accurate printing of a target colour |
EP2456623A4 (en) * | 2009-07-23 | 2013-01-16 | Hewlett Packard Development Co | Accurate printing of a target colour |
US8902483B2 (en) | 2009-07-23 | 2014-12-02 | Hewlett-Packard Development Company, L.P. | Accurate printing of a target colour |
Also Published As
Publication number | Publication date |
---|---|
DE69806154T2 (en) | 2003-02-13 |
US6072589A (en) | 2000-06-06 |
EP0981897A1 (en) | 2000-03-01 |
DE69806154D1 (en) | 2002-07-25 |
EP0981897B1 (en) | 2002-06-19 |
AU7108898A (en) | 1998-12-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0981897B1 (en) | Arrangement for efficient characterization of printing devices and method therefor | |
US5818960A (en) | Characterization calibration | |
Vrhel et al. | Color device calibration: A mathematical formulation | |
US5572632A (en) | Universal frame buffer for a rendering device | |
EP1014685B1 (en) | Dynamic optimized color LUT transformations based upon image requirements | |
EP0675636B1 (en) | Extended density color printing | |
AU662412B2 (en) | Color correction with a four-dimensional look-up table | |
KR100198208B1 (en) | Method and system for providing closed loop control between a scanned color image and the output of a color printer | |
US5333069A (en) | Technique for use in conjunction with an imaging system for providing an appearance match between two images and for calibrating the system thereto | |
US5857063A (en) | Multicolorant process control | |
US7965417B2 (en) | Tone correction table generation method and apparatus | |
EP0980628B1 (en) | Arrangement for high-accuracy colorimetric characterization of display devices and method therefor | |
EP2160009A1 (en) | Method for generating a color chart | |
US10853708B2 (en) | Color calibration | |
KR19980081002A (en) | An improved system, method and program for converting an externally defined four-dimensional dye into an equivalent four-dimensional dye defined by four inks associated with the printer | |
KR100278430B1 (en) | A system, method and program for converting an externally defined four dimensional colorant (cmyk) into an equivalent four dimensional colorant defined in terms of the four inks (c'm'y'k') that are associated with a given printer by using a three dimensional to four dimensional conversion process | |
US20100208304A1 (en) | Image correction method and image correction system | |
JP2002027276A (en) | Method for optimizing color target for printer model | |
US7580150B2 (en) | System and method for reproducing colors on a printing device | |
EP0446914A2 (en) | Method for electronic color processing | |
JP7297547B2 (en) | Image processing device, image forming device | |
EP1596576A2 (en) | Method for closed loop characterization | |
EP1478170B1 (en) | System and method for calibrating a printing device having light and heavy inks | |
US20040227967A1 (en) | System and method for calibrating a printing device having light and heavy inks | |
Green | Fundamentals of Device Characterization |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A1 Designated state(s): AL AM AT AU AZ BA BB BG BR BY CA CH CN CU CZ DE DK EE ES FI GB GE GH GM GW HU ID IL IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT UA UG UZ VN YU ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A1 Designated state(s): GH GM KE LS MW SD SZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML MR NE SN TD TG |
|
DFPE | Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101) | ||
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
WWE | Wipo information: entry into national phase |
Ref document number: 1998918099 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1998918099 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: JP Ref document number: 1998549229 Format of ref document f/p: F |
|
REG | Reference to national code |
Ref country code: DE Ref legal event code: 8642 |
|
NENP | Non-entry into the national phase |
Ref country code: CA |
|
WWG | Wipo information: grant in national office |
Ref document number: 1998918099 Country of ref document: EP |