WO1993025937A1

WO1993025937A1 - A method for calibrating hardware and software for the automatic prepress reproduction of color originals

Info

Publication number: WO1993025937A1
Application number: PCT/US1993/005367
Authority: WO
Inventors: Michael Fredrick Feasey
Original assignee: Michael Fredrick Feasey
Priority date: 1992-06-12
Filing date: 1993-06-01
Publication date: 1993-12-23

Abstract

A process is disclosed herein for calibrating scanners and software applications running on desktop computers, to hereby apply the calibration (Figs 1, 2, 4) automatically or manually. That such calibration corrects for the deficiencies of the various hardware, software, and the printing process for which the hardware and software is being calibrated. That within this process calibration plaques electronically generated on computers and photographically produced from masters or electronic originals are used to calibrate scanners and software applications that can be programmed for color correction. That scanned color originals when processed by the calibrated hardware and software are viewed as they will be printed on calibrated monitors. That upon being accepted or modified to suit, the resultant data will be used to produce color corrected separations. That the original will be accurately reproduced by a printing process.

Description

A METHOD FOR CALIBRATING HARDWARE AND SOFTWARE FOR THE AUTOMATIC PREPRESS REPRODUCTION OF COLOR ORIGINALS

This invention relates to a color application interface for calibrating color scanners and software applications running on a computer. That the resultant calibration settings, color processes image data to specific printing parameters for offset photo-lithography, gravure, letterpress and all systems using a subtractive color process. That the resulting process, automatically applied to color originals will reproduce them when printed. In order to print a color original by these processes, cyan, magenta, yellow, black inks in combination and exact proportion are printed sequentially onto paper. To achieve this, subtractive color separations of cyan, magenta, yellow are made through additive red, green, blue color filters to reproduce the original. A black printer separation is also produced through combinations of these filters to correct for the hue error of the process color inks used in the above stated printing processes. In photographic and similar dye and toner process where the hue error and grayness of the colors are nearer to ideal, a black printer is not required. Color separations can be produced by a photographic process, using panchromatic light sensitive material, either continuous tone or high contrast Nth type film. The process most commonly employed, uses a color scanner, either with photo- multipliers or charge couple device, known as CCD. Gamma, tone and color correction is required to correct the raw red, green, blue scanned data. The traditional photo-multiplier, digital programmable scanners are provided with this capability. To not only correct for the raw data and for errors in the original, but also for the inks used in the printing process. This is due to the pigment deficiencies of hue error and grayness, also saturation in the pigments. The printing process and the paper used, have also to be accounted for, as well as the tonal compression of the original. That when printed the result will simulate the original, that it will appear to be a reproduction. Although the traditional digital scanner is programmable, operator skill is required to fine tune the reproduction process. The newer technology, lower cost desk top color scanners do not have programming capabilities, and often are not suitable for the production of prepress color separations.

Desktop publishing known as DTP, for which the aforementioned scanners were developed, were introduced by manufactures of personal computers, Apple and IBM among others, as well as software developers, originally to produce office documents and similar. Hardware and software developments have been introduced to provide system capabilities that approximate traditional scanning technology. To also provide operator access to visual representation of a pre-processed image data on a color monitor. That the image can be manipulated to correct for scanner deficiencies, printing parameters and aesthetic considerations as well as distortions required for the reproduction of the original as previously described herein. These are based on patents that disclose data conversion tables, known as look-up tables that change color data to accommodate for a number of these parameters. However, these processes applied to traditional electronic systems require the skills of a trained operator using empirical correction to achieve optimum results, including U.S. Pat No. 3,612,753 issued to Korman on Oct. 12, 1972; U.S. Pat. No. 3,893,166 issued to Pugsley Jul, 1. 1975; U.S. Pat No. 4,037,249 issued to Pugsley on Jul. 19, 1977; U.S. Pat. No. 4,058,828 issued to Ladd on Nov. 15, 1977; U.S. Pat. No. 4,060,829 issued to Sakamoto on Nov. 29, 1977; U.S. Pat. No. 4,127,871 issued to Sakamoto on Nov. 28, 1978; U.S. Pat and Japanese Specification No. 55- 115043 by Ahei and Tamada published Sep. 4, 1980. U.S. Pat. No. 4,500,919 issued to Shreiber on Feb. 19, 1985 encompassing the developments of previous patents, to also introduce a color monitor as a human interface to show a color representation of the scanned image that adjustments can be made based on the evaluation of the same. The monitors calibration described in this prior art, assumes a 5,000 degree Kelvin white point color temperature displayed on a monitor [TV], to be a simulation of white paper reflecting 5,000 degrees Kelvin light, stating that both peak white point [TV] and illumination must be of a suitable color temperature, with the example of 5.000K being given. As white papers have various color reflection indexes, reflected light from the paper will not be 5,000 degrees Kelvin, therefore with the monitor set to 5.000K this white point will not match the light reflected from the paper. Further, this prior art does not stipulate that the monitor should be adjusted to match the color of the paper, that it should be 5.000K. With this parameter being applied then the monitor image cannot be accurately compared to the printed image as the white point color temperature of the monitor is not that of 5.000K lights reflected from white paper. Therefore, monitors used in this process are not accurately calibrated, and do not display the image as it will print.

The software programs produced for DTP, in many cases provide tone and color controls, also look-up tables with basic color formulations for converting red, green, blue data to cyan, magenta, yellow color separation data disclosed in the patents. Look-up tables to convert scanner input data, especially desktop scanners to a common standard, that software program look-up tables can convert to color separation data, is not provided, especialy exact high light and shaddow entries (enter white/black) needed for prepress seperations. The Schriber Patent describes look-up tables produced with the aid of a colorimeter reading printed color charts. The lookup tables are then refined by trial and error. Previous patents disclose look-up tables based on theoretical equations of the printing process, that encompass hue error and grayness, also additivity and proportionality failure of inks. Although Shriber's intention was to provide the novice or semi-skilled with the means to produce color separations of publication quality, it has been found at this skill level trial and error is used to produce mediocre results known at times as pleasing color. That in reality, the skill of dot etchers and analogue scanner operators of 1940-1979 is required in this process to produce quality.

Thus with the princables, of the Shriber prior art being applied to desktop publishing, color separations produced on desk top computer systems using personal computers, are made by scanning the original and manipulating the digital data within software applications. To thereby compensate for the inaccuracies of the scanner, the impurities of the inks used in the printing process and the printing processes, also personal preference on the appearance of the reproduction. The color monitors used to view an image are not calibrated to exactly show an image as it will print. Such calibration that is applied is usually to an individual workstation and operator preference. Thus, the image is usually monitored for final printing quality by interrogating the color in dot percent printing values; or via a complex procedure of image comparison, comparing the on screen image to that of printed samples, or on screen image blanking to indicate the monitor color gamut is out of the printing range. These techniques, presupposes operator skills to interpret the variables in the processes involved. This is tedious, slow and subjective, with the results being inconsistent and usually of poor quality due to the lack of skill.

A need is apparent for a process that encompasses and applies all the prepress parameters automatically. That no greater skill is required than pushing a computer key and accepting the final image on the monitor after processing. That if aesthetic adjustments are needed these can be achieved with easily understood tools within the application. It is conceivable with such a system, that quality color reproduction would be within the reach of customers of quick printing shops as well as quality trade shops.

This invention relates to a method, that scanned color originals, digitized by a personal computer desk top system, are automatically processed. To produce color separations in preparation for color reproduction by one of the printing processes; offset photo-lithography, gravure, letterpress, or similar process using subtractive color inks or dyes.

Accordingly, it is the object of the present invention to provide a method for efficiently producing color separations using unskilled labor. That when printed will be an accurate reproduction of the original that accounts for the limitations of the printing process. The color separations when processed, can be viewed on a color monitor as an accurate proof of how the result will print. Thus, enabling fine tuning adjustments to be made to match the original or meet the aesthetic requirements of advertiser, • publisher or printer. It has been found this objective can be achieved by accurately calibrating hardware and software to specific values using calibration plaques. These values are based on the results of printing color charts of the standard ink sets used in the printing industry. To also calibrate 24 bit color monitors with line resolutions of 640 X 460 and above, used with desk top computers. This being achieved with a monitor calibration device that specifies the white point color temperature to control the color gamut, brightness and contrast of the color monitor, and to also account for the brightness of the ambient light. With monitors so calibrated, the image can be displayed as it will print. A separate patent is being requested for such a device. That with the defined color reproduction parameters defined they are automatically applied in sequence to the color correction software application. This being achieved with a programmed macro software application, that with one key stroke the macro program is activated to apply the defined color correction parameters to the scanned image of the original. Alternatly, the defined color correction parameters are applied automatically through a software plug-in modual to the scanned image of the original. Based in the image displayed on the calibrated monitor, the image can then be modified as required.

In this aspect therefore several objectives and advantages of the invention are:

[a] to make accurate photographic color copies, transparencies, negatives and prints of industry standard color plaque guides onto various photographic materials,

[b] to provide as an alternate to [a], color plaques produced electronically on a computer and imaged to photographic material via a film recorder,

[c] to provide electronically produced color plaques, similar to that described in [b] but not imaged to photographic material, [d] to provide scanners having red, green, blue, known as RGB, gamma adjustment, RGB gray balance value calibration settings, that the scanner can be calibrated to such values using the gray scale data of the color plaques produced by the processes described in [a] or [b], then.

[f] to provide by interrogating printed color charts by 5,000 degree Kelvin light of the ANSI standard PH2.30, and comparing the chart to the calibration plaque viewed by light of the same standard or viewing the . .

electronic chart on a calibrated monitor as previously described, with the color correction application gamma at 1.0 and the monitor gamma at 1.8, the parameters described in original dot percent values for tone compression, gray balance and color correction being determined and from this,

[g] to provide, using the scanned color data of the calibration plaques described in [a] or [b], and that described in [c], color correction parameters based on the data determined by the process described in [d], that as an application interface and applied to color reproduction software running on a computer, corrects the scanned data to prepress color correction parameters that accounts for, tone compression, hue error and grayness of printing inks, and the additivity and proportionality failure of the same and the printing process for the accurate reproduction of the original via the production of color separations, then

[h] to provide using a software macro program with one computer key stroke, to automatically apply the prepress parameter defined through the process stated in [e], to the automatically loaded color correction software and scanned file data, into the memory of the computer, that has been activated with the same key stroke and macro program, then with the image corrected for reproduction, removing the original file from Folder A to Folder B that the next scanned image in Folder A is positioned in readiness for processing, or to provide for the automatic process described above, to be applied through a software plug-in modual as an interface, then

[i] to provide after automatic processing for viewing the image on a calibrated monitor, as it will be printed, that adjustments as may be required to the image to correct for minor deficiencies, or to meet the requirements of the end user can be applied.

The following examples are set forth to illustrate more fully this invention but are not intended to limit its scope described herein.

EXAMPLE 1

In this example of the process, a Macbeth ColorChecker being a calibration chart of Macbeth a division of Kollmorgan Corporation, Little Britain Road, Drawer 950, NewBurg, New York 12550. PhotoShop, a software product of Adobe Systems Inc., 1585 Charleston Road, Mountain View, CA 94039-7900 and Quickeys a software product of CE Software Inc., P.O. Box 65580, West Des Moines, Iowa 50265 are used with System 7.0 (or versions above) a product of Apple Computer Inc., 20525 Mariani Avenue, Cupertino, California 95014. Also a 20 inch color monitor and graphics interface card by Radius Inc., 1710 Fortune Drive, San Jose, CA 94063 is used displaying 16.4 million colors. A monitor calibrator of GA Pro-Tek Calibrator of GA Pro Techniques, Fairfield House, Ford, Shrewsbury, SY5 9LG, U.K., is used. Together with an Apple Macintosh computer. However, software and hardware with similar characteristics can also be used.

Through-out the process described in this Example, the viewing conditions are to be those of the ANSI [American National Standards Institute] Standard PH2.30 and IES [Illumination Engineering Society] VDT Standard. In that the ambient lighting is 5,000 degrees Kelvin at 30 Foot Candles. The transparency viewers are illuminated by 5,000 degree Kelvin lights at 300 - 400 Foot Candles. The above description provides for the working area of the computer where the color monitor is being viewed, that the transparency viewer is also located and where the printed color charts are used to define color correction. Should the need arise to view the printed color charts in lighting of a higher illumination, then the ANSI PH2.30 standard applies at a Foot Candles level of 100 - 200. The transparency viewer is used in this lighting condition if it is necessary to view transparencies to be compared with the printed color chart. The color monitor should not be viewed in this lighting condition.

FIG. 1 , shows the scanner Histogram Table A herein described, this being the collective data of the gray windows of the Color Calibration Plaque, including the black separations between the windows, where they apply.

FIGS. 2, 3, 4 shows the Tables B,C,D, herein described for the color application interface parameters, represent the color and neutral windows of the Color Calibration Plaque. With each window of the Table providing the cyan, magenta, yellow, black dot percent values for the color or gray window.

A copy of the Macbeth ColorChecker is photographed by noon day sun, to produce color transparencies, negatives and prints. That the gray tones of the transparencies and print reproduce as neutral, without color cast and the color prints being of a range of 2.0 +- 0.03 and with a minimum density of 0.05 and the transparencies of a range 3.3 +- 0.30 with a minimum density of 0.30.

Using a GA Pro-Tek Calibrator monitor calibration device for which a patent request has been made, or similar. A color monitor of a desktop personal computer is calibrated to specific white point color temperature, brightness and contrast levels revealed in the patent application.

The Color Calibration Plaque is scanned and through PhotoShop displayed on a color monitor via the random access memory of the computer. If the scanner used to digitize the image does not interface directly to PhotoShop via a software Plug-in, the scanned TIFF file of the image is opened in the PhotoShop application. The scanners accuracy to reproduce the neutral gray tones of the Color Calibration Plaque is determined by interrogating the red, green, blue [RGB] values of the Color Calibration Plaque gray tones via the histogram facility of Photoshop. The data is compared to Table A, from which the required adjustment are determined for the RGB gamma curves within the scanner software interface, to meet the requirements of Table A.

The scanner input parameters of Table A, are defined by:

[a] Through the Edit Menu, Preference, Separation Set-up is selected and Normal, GCR and Black Ink 100 percent are defined in the Dialogue Box.

[b] Following the selection of positive or negative mode within the scanner software interface dependent on the original being a negative or positive Color Calibration Plaque, the plaque is scanned.

[c] The scanned data of the plaque is interrogated within RGB Mode of PhotoShop. This is achieved using the Marquee tool and selecting the gray pallet windows of the plaque as a group. The Histogram facility of the application is used for this purpose, Dialogue Box being opened through Image Menu.

[d] The scanner interface RGB gamma curves are adjusted to provide a neutral gray balance for the gray pallet windows of the plaque.

[e] The range parameters are then defined by converting the plaque data from RGB to CMYK through the Mode Menu. The Pallet Dialogue Box when selected and opened through Windows, and CMYK selected.

[f] Using the Eye Dropper tool, set to 5 by 5 Average through the General Preference, the white pallet window and black pallet window of the Color Calibration Plaque are interrogated.

[g] The scanner interface is adjusted to achieve a minimum dot percent of 1-2, and a maximum 95 percent dot value, +-2 percent.

With the scanner adjusted to to the specification of Table A, the plaque data is used in conjunction with Tables B, C, D described below, to calibrate the PhotoShop software application for specific ink sets and printing processes, which comprises the steps of:

[1] PhotoShop is loaded into the memory of the computer with the default preference settings remaining as supplied with the program, with the exceptions as stated herein.

[2] Preferences is selected through the File Menu and the Monitor Gamma is set to 1.0.

[3] Through the Printing Set-up of Preferences, the Chromatic, Under Color Removal [UCR] or Gray Component Replacement [GCR] of Table B provides the data needed to define the curves and related settings to achieve these parameters.

The Chromatic, UCR or GCR parameters of Table B, are defined by:

[a] Scanning the Color Correction Plaque with the gray balance and range of the scanners interface being set to the correct parameters of Table A.

[b] Interrogating the printed color chart of the inks which the color correction program will be formulated, and selecting the neutral grays of the chart, the Chromatic or Gray Component Replacement parameters are defined. The gray balance parameters are plotted on graph paper as gray balance curves.

[c] Selecting Eye Dropper from the Tool Box and the Pallet window open and CMYK selected. Separation Set-up from the Preferences menu is opened, and within the Dialogue Box, GCR is selected, the Black Ink Limit set to 100 percent, and Total Ink Limit set to 300 percent, Custom is selected.

[d] Interrogating the gray pallet windows of the plaque, adjustments are made to the Custom Curve to achieve the black and cyan parameters of the graph. These parameter are saved as well as being applied to the plaque.

[e] Through the Mode Menu, CMYK is selected and plaque gray pallet windows are interrogated to confirm that the applied parameters have not changed.

[4] The Printing Ink Set-Up, applied through Preferences, is set to AD-LITHO (NEWSPRINT).

[5] The scanned image of the plaque is opened and displayed on the monitor.

[6] Through Image Menu, Levels dialogue box is opened and the Auto enter white/enter black is selected and applied. Reducing the lowest white point to zero dot percent in printing ink values, and the highest black point to 100 percent in printing ink values.

[7] Through the Mode Menu, CMYK is selected by which the plaque data is converted from RGB to the color separation parameters of cyan, magenta, yellow, black.

[8] Through Image Menu, Levels dialogue box is opened and enter white and enter black parameters are entered as defined in Table C.

The Enter White and Enter Black parameters of Table C, are defined by:

[a] Interrogating the printed color chart of the inks that the prepress parameters are being defined, minimum printing dot percent combination of cyan, magenta, yellow inks and the maximum printing dot percent combination of cyan, magenta, yellow and black inks, for either Chromatic, UCR or GCR is thus defined.

[b] Through Image Menu, select Levels and with the Eye Dropper select the white pallet window of the Color Calibration Plaque.

[c] Selecting C, M, Y in the Levels Dialogue Box in turn, the lower right slider is moved to achieve the selected minimum printing dot percent as defined by [a].

[d] Selecting C, M, Y, K in the Levels Dialogue Box in turn, the lower left slider is moved to achieve the selected maximum printing dot percent as defined by [a].

[e] These parameters are saved and also applied to the image and entered into Table C.

[9] Through the Windows Menu, the Pallet dialogue box is opened, and CMYK is selected.

[10] From the Tool Box the Eye Dropper is selected, through double clicking the Mouse the Dialogue box is opened and the Pixel Selection is confirmed that it is set to average 5.

[11] Using the Eye Dropper tool, the gray pallet windows of the Color Calibration Plaque are interrogated for cyan, magenta, yellow, black dot percent values. These values are compared to those of the gray balance Table D.

The Gray Balance parameters of Table D are defined by:

[a] The printed color chart of the inks that the prepress parameters are being defined is interrogated to find the neutral grays through-out the range of printed tonal values that represent the gray pallet windows of the Color Calibration original, transparency or reflection as appropriate. Where negatives are used the print should be used for reference.

[b] The original dot percent values of cyan, magenta, yellow, black, from which the printed gray balance was derived in [a] are logged as a graph.

[c] The gray pallet windows of the plaque as step [8] is interrogated, and noting the cyan values of the gray pallet windows they are logged on the gray balance graph. The cyan, magenta, yellow values at the points the cyan values intersect the graph are logged.

[d] The gray pallet windows of the plaque are interrogated and with the Curves dialog Box opened Through the Image Menu. The logged gray balance parameters are applied through selecting in turn M, Y, [Magenta, Yellow] and adjusting the magenta and yellow to balance with the cyan. Where the printing dot percentages of the black Gray Component Replacement or Chromatic parameters apply, it is required that this is taken into account by interrogating the printed color chart.

[e] The cyan, magenta, yellow, black dot percent values defined by [d] for the gray pallet windows of said plaque are logged to produce the gray balance values of Table D.

[12] Through Image Menu, the Curves dialogue box is opened. Using the Curves dialogue Box, Eye Dropper and Pallet Dialogue Box, the gray balance cyan, magenta, yellow black values of the plaque are changed as required to those specified in Table D. When completed the contents of the dialogue box are saved and applied to the image.

[13] Using the Eye Dropper and Pallet Dialogue Box, the red, green, blue, cyan, magenta, yellow pallet windows of the plaque are interrogated. [14] Through Image, the Hue, Saturation, Lightness Dialogue Box is opened. Using the Eye Dropper and Pallet Dialogue Box, the color correction values cyan, magenta, yellow black values of the red, green, blue, cyan, magenta, yellow pallet windows of the plaque are changed as required to those specified in Table D. When completed the contents of the dialogue box are saved and applied to the image.

The color correction parameters of Table D are defined by:

[a] The printed color chart color values are compared with those of the color pallet window of the original Color Calibration Plaque, transparency or reflection copy as appropriate. Where negatives are used the print should be used for reference.

[b] The colors of the printed color chart that match the original viewed by 5,000 degree Kelvin light are logged. Where an exact match is not possible a process of interpolation is applied. This may also be required when defining the gray balance parameters.

[c] The red, green, blue, cyan, magenta, yellow color pallet windows of the plaque displayed on the monitor are interrogated and changed through the controls in the Hue, Saturation, Lightness Dialogue Box, that is opened through the Image Menu.

[d] The cross reference color pallet windows of said plaque are checked against the values assigned for them as defined in [b].

[e] As it may not be possible to achieve the color parameters as defined from the printed color chart, it may be necessary to produce a compromise in both color correction and gray balance by adjusting these parameters. When the best compromise is achieved the color correction values are logged in Table D, and where the gray balance parameters have been changed, those previously logged in Table D are changed to the new parameters.

[f] The color correction and any changes in gray balance that have been applied through Curves are applied to the image, first removing from the image the previously applied gray balance parameters through the Edit Menu.

[15] The color cross reference windows of the plaque, being the first two top rows of the plaque, are also checked for CMYK color content via the Eye Dropper tool and the Pallet. These values are compared to those defined in Table D to ensure they are within tolerance. Adjustments to the red, green, blue, cyan, magenta, yellow pallet windows of the plaque, to achieve a compromise between these color and the cross reference colors may be required. The gray balance windows of plaque are checked to ensure the defined parameter are remaining true, within tolerance.

Should changes to the gray balance be required, the appropriate Dialogue Box is opened and loaded with the previously saved parameters of the ink set that is being defined. The required changes are then applied and saved and the gray balance and color parameters of the plaque windows entered into Table D.

[16] Through the Edit Menu, Preferences, Ink Setting is selected. Within the Dialogue Box, Custom is selected and the color, black and gray balance values changed, that the tone and color of the plaque displayed on the monitor match those of the printed color chart for the color correction being defined.

[17] A digital data storage device, hard drive, Syquest, optical or similar is selected through the computers system graphic user interface.

[18] The storage device is opened to be displayed on the monitor. Through the graphic user interface menu, File is selected and a New Folder is opened in the window of the storage device. The New Folder is named with the ink set and scanner for which the color correction parameter have been defined through the procedures in the preceding stated above. Preceding the File name, numeral 1 is entered.

[19] The cyan, magenta, yellow, black, Enter White Enter Black parameters as specified in Table C are loaded into the file, and the numeral 1 entered to proceed the designation.

[20] The Gray Curves parameters are loaded into the File and the numeral 2 entered to precede the designation.

[21] The Hue, Saturation and Lightness parameters are loaded into the File and the numeral 3 entered to precede the designation.

[22] A second New Folder is opened in the assigned data storage device. This is named 2. IN. A third New Folder is opened in the same storage device and named 3. OUT. In so numbering the files they will appear in the order as numbered. With the file containing the color correction parameters being automatically placed to appear at the top of the data storage device window when the window contents are identified by name. [23] The open window of the data storage device displayed on the monitor of the computer, is placed that the top right corner butts to the top right corner of graphic user interface window displayed on the monitor.

[24] A scanned image is loaded into the IN Folder, preferably this should be a small file.

[25] With PhotoShop closed, Quickeys is opened and Record Sequence is selected and programmed through the following:

[a] PhotoShop is opened.

[b] Though Preferences, Ink Settings is opened and AD-LITHO (NEWSPRINT) is selected.

[c] Through File, Open, the window of the data storage devise defined in [16], and the IN Folder is selected and opened, from which the file that has previously been saved is opened.

[d] The Levels window is opened, the software Auto enter white/enter black is selected and applied to the image.

[e] Through the Filter Menu, Sharpen More is selected and applied to the image.

[f] Through the Filter Menu, Sharpen Edges is selected and applied to the image.

[g] Through the Mode Menu, CMYK is selected.

[h] Levels is selected, and the Enter White/Enter Black, are loaded from the Color correction File stated in [8] and applied to the image.

[i] Hue, Saturation, Lightness is selected and the pre-defined parameters loaded for the Color Correction Folder.

[j] Through Preferences and Ink Settings, the monitor ink setting for the process inks that the color correction is being defined is loaded.

[k] The image on the monitor is displayed as it will print. The image can also be viewed as an original by changing the gamma of the monitor, through the applications monitor control. Changes to color or tone as needed to suit the end user can be made with the use of the tools provided within the software program.

[26] To ensure that the software application used in the process has a linear response for imaging. In that the dot percentages of the image are accurately reproduced to film at output gray scale tint blocks of 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95 and 100 dot percent are created and imaged to high contrast photographic film on the calibrated imagesetter. If the dot percentages, measured on a densitometer, do not accurately record, then adjustments are made in the Screen Control of the Print Set-up Dialogue Box by the dot percent value of the recorded error. Increasing or decreasing through-out the tonal range to achieve a linear response.

EXAMPLE 2

Example 1 describes a process in which a color calibration plaque is produced by photographing the Macbeth ColorChecker. In this example the color calibration plaque is produced electronically on a computer and imaged to photographic color material via a film recorder. All other aspects of the process remain as Example 1.

EXAMPLE 3

Example 1 described a process for the color reproduction of conventional originals that are at hand for processing. This example is for the processing of color images that have been scanned and digitized at remote sites. Therefore, the originals cannot be accurately reproduced as they cannot be viewed. This is the case with news wire transmitted photo's. This process can also be applied to images that although the original is on site for accurate color reproduction, artistic license has been used to create a special effect or retouch the image outside the scope of the automatic color reproduction parameters of the process described in Example 1. All other aspects of the process remain as Example 1.

A Color Calibration Plaque created using PhotoShop, to electronically simulate the Macbeth Color Checker. A desk top personal computers video monitor color display is calibrated to specific white point color temperature, brightness and contrast levels. This is achieved by using a GA Pro-Tek Calibrator monitor calibration device for which a patent request has been made, or like device.

[1] PhotoShop is loaded into the memory of the computer.

[3] Through the Printing Set-up of Preferences, the Chromatic or _ .

Gray Component Replacement of Table B provides the data needed to define the curves and related settings to achieve these parameters.

The Chromatic or Gray Component Replacement parameters of Table B, are those as defined in Exhibit 1 item [3].

[4] The Printing Ink Set-Up, applied through Preferences, is set to ANPA-AD/LITHO.

[5] The digital image of the Color Calibration Plaque is opened and displayed on the monitor.

[6] Through Image Menu, Levels dialogue box is opened and the Auto enter white/enter black is selected and applied. Reducing the lowest white point to zero dot percent in printing ink values, and the highest black point to 100 percent in printing ink values. [7] The gray and color values of the plaque displayed on the monitor are compared to those in the printed color chart of the printing process the color correction is being calibrated to. The original dot percentages of cyan, magenta, yellow and black of the colors of the chart that match the plaque colors, or those achieved through interpolation are entered into Table D.

[8] Through the Mode Menu, CMYK is selected by which said data is converted from red, green, blue to the color separation parameters of cyan, magenta, yellow, black.

[9] Through Image Menu, Levels dialogue box is opened and enter white and enter black parameters are loaded for this parameter defined in Table C.

The Enter White and Enter Black parameters of Table C, are defined in Exhibit 1 item [8].

[10] Through the Windows Menu, the Pallet dialogue box is opened, and CMYK is selected.

[11] From the Tool Box the Eye Dropper is selected, through double clicking the Mouse the Dialogue box is opened and the Pixel Selection is confirmed that it is set to 5 by 5 Average.

[12] Using the Eye Dropper tool, the gray pallet windows of the plaque are interrogated for cyan, magenta, yellow, black dot percent values. These values are compared to those of the gray balance Table D.

[13] Through Image Menu, the Curves dialogue box is opened. Using the Curves dialogue Box, Eye Dropper and Pallet Dialogue Box, the gray balance cyan, magenta, yellow black values of the plaque are changed as required to those specified in Table D. When completed the contents of the dialogue box are saved and applied to the image.

[14] Using the Eye Dropper and Pallet Dialogue Box, the red, green, blue, cyan, magenta, yellow pallet window of the plaque are interrogated for the cyan, magenta, yellow, black values.

[15] Through Image, the Hue, Saturation, Lightness Dialogue Box is opened. Using the Eye Dropper and Pallet Dialogue Box, the color correction values cyan, magenta, yellow black values of the red, green, blue, cyan, magenta, yellow pallet window of the plaque are changed as required to those specified in Table D. When completed the contents of the dialogue box are saved and applied to the image.

[16] The color cross reference windows of the plaque, being the first two rows of the plaque, are also checked for CMYK color content via the Eye Dropper tool and the Pallet. These values are compared to those defined in Table D to ensure they are within tolerance. Adjustments to the red, green, blue, cyan, magenta, yellow pallet windows of the Color Calibration Plaque, to achieve a compromise between these color and the cross reference colors may be required. The gray balance windows of the plaque are checked to ensure the defined parameter are remaining true, within tolerance.

Should changes to the gray balance be required, the appropriate Dialogue Box is opened and loaded with the previously saved parameters of the ink set that is being defined. The required changes are then applied and saved.

[17] Through the Edit Menu, Preferences, Ink Setting is selected. Within the Dialogue Box, Custom is selected and the color, black and gray balance values changed, that the tone and color of the plaque displayed on the monitor match those of the printed color chart for the color correction being defined. [18] A digital data storage device, hard drive, Syquest, optical or similar is selected through the computers system graphic user interface.

[19] The storage device is opened to be displayed on the monitor. Through the graphic user interface menu, File is selected and a New Folder is opened in the window of the storage device. The New Folder is named with the ink set and scanner for which the color correction parameter have been defined through the procedures [1] - [18] stated above. Preceding the name numeral 1 is entered.

[20] The cyan, magenta, yellow, black, Enter White Enter Black parameters as specified in Table C are loaded into the file, and the numeral 1 entered to proceed the designation.

[21] The Gray Curves parameters are loaded into the File and the numeral 2 entered to precede the designation.

[22] The Hue, Saturation and Lightness parameters are loaded into the File and the numeral 3 entered to precede the designation.

[23] A second New Folder is opened in the assigned data storage device. This is named 2. IN. A third New Folder is opened in the same storage device and named 3. OUT. In so numbering the the files they will appear in the order as numbered, with the file containing the color correction parameters being automatically placed, to appear at the top of the data storage device window when the window is defined that the contents are listed by name.

[24] The open window of the data storage device displayed on the monitor of the computer, is placed that the top right corner butts to the top right corner of graphic user interface window displayed on the monitor.

[25] A scanned image is loaded into the IN Folder, preferably this should be a small file.

[26] With PhotoShop closed, Quickeys is opened and Record Sequence is selected and programmed through the following:

[a] PhotoShop is opened.

[b] Though Preferences, Ink Settings is opened and ANPA/AD Pro is selected.

[e] Through the Filter Menu, Sharpen More is selected and applied to the image.

[g] Should the images in general be of low resolution, by excessive data compression or through low resolution scanning, an alternative program should include only Sharpen.

[h] Through the Mode Menu, CMYK is selected.

[i] Levels is selected, and the Enter White/Enter Black, are loaded from the Color correction File stated in [18] and applied to the image.

[j] Hue, Saturation, Lightness is selected and the pre-defined parameters loaded for the Color Correction Folder.

[k] Through Preferences and Ink Settings, the monitor ink setting for the process inks that the color correction is being defined is loaded.

[I] The image on the monitor is displayed as it will print. The image can also be viewed to the range of an original by changing the gamma of the monitor through the applications monitor control. Changes to color or tone as needed to suit the end user can be made with the use of the tools provided within the software program.

[27] To ensure that the software application used in the process has a linear response for imaging. In that the dot percentages of the image are accurately reproduced to film at output gray scale tint blocks of 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95 and 100 dot percent are created and imaged to high contrast photographic film on the calibrated imagesetter. If the dot percentages, measured on a densitometer, do not accurately record, then adjustments are made in the Screen Control of the Print Set-up Dialogue Box by the dot percent value of the recorded error. Increasing or decreasing through-out the tonal range to achieve a linear response.

The attached tables are those described in the examples 1, 2, and 3. Fig 1 - Scanner Histogram Gray Balance Table A

Fig 2 - Color Application Interface Gray Blance Table B

Fig 3 - Color Application Interface Enter White/Black Table C

Fig 4 - Color Application Interface Gray Balance/Color Correction Table D

Claims

I CLAIM: 1. A color application interface that provides a method and process for producing color calibration plaques for calibrating color scanners and software applications that can be programmed for color ^' reproduction, running on a computer that receives data from scanners, to thereby account for scanners reproduction error, for the hue error and grayness and additivity and proportionality failure of process color printing inks, and the various printing processes, that wherein these calibration parameters are applied automatically to images of scanned originals via a macro or aplication plug-in modual within a software application that can be so programmed, that the resulting color separation so produced reproduce the original when printed.

2. A process according to Claim 1 , wherein the scanner is un- calibrated.

3. A process according to claim 1 , wherein said macro program is not present to automatically apply color correction parameters, that the parameters are manually applied.