ColorAnt | Color Editor

Color Editor

Manual editing of patches and best possible spot color conversion

Color Editor

The Color Editor tool covers several applications:

  1. Best possible conversion of colors (usually spot colors) using ICC profiles.
  2. Saving spot colors converted with Color Editor in various color formats for use in other applications.
  3. Manually changing color names.
  4. Manually changing Lab values and device values assigned to a color patch.
  5. Adding or removing color patches.

Overview of the Color Editor

On the left side is a table with the colors of the loaded measurement file. It contains the following information:

  • Color: Name of the color
  • Measurement: Measured color values in Lab (spectral values are retained but shown as Lab)
  • Current (DCS): Specifies the current device values. Displays the device values after applying the settings and functions on the right side.
  • Profile (DCS): Displays the device values resulting from a conversion using the selected profile on the right-hand side.
  • dE00 (Current): Displays the absolute colorimetric DeltaE 2000 values, which result from the measured Lab values and the current device values.

Single, multiple or all color values can be selected in the table and then edited with the tools on the right. The color table can be sorted by Color or dE00 (Current) by clicking on the column headings.

Below the table are two buttons to Add or Delete patches as well as the Invert Selection button.

Invert Selection: Provides a quick and easy way to reduce a large number of displayed colors of a large data set to only a few colors. Simply select the desired color patches, click Invert Selection followed by the Delete button. Now you are working on your individual color selection.

Search: Helps to find and edit specific colors of large data sets. Type in the name of the desired color and the list will show only colors with those name components.

Tip: Combine the Search with Invert Selection

If, for example, you would like to edit all colors with the name component ‘Red’ of a Pantone library as a small list, enter ‘Red’ in the Search.

Select the colors found, then delete the search term and click on Invert Selection.

By pressing the Delete button, only the colors with the name component ‘Red’ remain in the list. All others are removed.

Spot Color Report: Generates a PDF report that can be used to check the conversion of spot colors before actually printing.

The spot color report shows the results achieved by a spot color conversion in relation to deltaE00, deltaE76, and the separation into process colors. This allows the accuracy of spot color conversions to be checked before processing or printing, and to determine in advance how spot colors (e.g., Pantone® or HKS and other colors) of specific PDF and image files are converted.

A spot color library with multiple spot colors such as Pantone, HKS or other colors can be color converted with a target ICC profile to check for the resulting process color breakdowns (DCS). The report provides the color name for each spot color, the process color breakdowns, the expected deltaE2000 and deltaE76 values, and an overall evaluation in terms of average and maximum deltaEs.  It also includes the median and how many colors are reproduced within a tolerance of 1 and 2.5 dE00 as well as within the user-defined dE00 limit.

The report also contains an information column that shows, among other things, whether a color is out of gamut.

Measurement Information

Shows the Name, the measured Lab value (CIE) and the current device value (DCS) including the color space for the selected color field.


Color Conversion Settings

After selecting an ICC Profile, first the DCS values are calculated using the Absolute Colorimetric rendering intent.

However, these are not always the best possible color values, neither with regard to the smallest DeltaE nor to printability.

Therefore, various optimization modes are available in the Color Conversion Settings, which can be applied to the colors selected on the left side of the table.

It is also possible to apply different modes and colors to individual colors.

Define the Profile and the Mode for the conversion of the measured values. Six modes are available for the color conversion:

  1. Precise Match – Proofing
    Spot colors are reproduced as accurately as possible on a proof printer. This method is not suitable for production as it may use all process colors for spot color simulation to achieve the best result (based on DeltaE 2000). The full tone is calculated with the aim of achieving the smallest possible DeltaE 2000 value. No channel reduction or print optimization is applied.
  2. Visual Match – Utilize More Channels
    Produces visually the best possible conversion with high color accuracy and with excellent printing properties. Full tones of spot colors are converted with as few channels as possible and still remain colorimetrically accurate. This method is suitable for digital printing, large format inkjet printing or offset printing with a fine screen ruling and good register accuracy.
  3. Use the least Amount of Channels possible
     A good method to convert full tones of spot colors with a minimum number of channels and still get colorimetric accurate results. Choose this method for packaging printing where pure colors are desired. One or two-color combinations are also included in the search for the best possible color combination.
  4. Use one Output Channel only
    Useful for print packaging production. The spot colors used for text and bar codes will be converted using a maximum of one process color.
  5. Use a Maximum of two Channels
    Uses one or two output channels. Best for one or two process colors providing the best colorimetric match selected for each spot color automatically. The results are very clean separations that are easily printed, but not necessarily very exact in colorimetric terms. It is recommended to only use this function for individual, manually created spot colors.
  6. Use a Maximum of three Channels
    Uses one to three output channels. Similar to the calculation method Use the least Amount of Channels possible. No more than a maximum of three channels should be used. Choose this method for packaging printing, where the purest possible colors are to be produced and not more than three process colors for spot color conversion must be used. Single-color and two-color combinations are also included in the search for the best color combination.

dE00 Limit: Colors exceeding the set threshold are marked with a warning symbol.


Optimize Output Values

Displays the current device values for the selected ICC profile.

By clicking on dE76 or dE00 the deltaE can be minimized for each color.

Automatic: Uses the selected ColorLogic calculation mode, typically reducing the number of channels for better printability.
Note: By deactivating the checkboxes for the color channels, the values displayed in the number fields are fixed (for example 0% or 100%) so that they are not changed when applying dE76 or dE00. However, this does not apply to Automatic, here, all channels are always taken into account.

Revert: Undoes all changes and reverts back to the original DCS values initially calculated using the selected ICC Profile.

Color Information

Displays various information about the selected color:

Reference: Measured Lab value of the color
Profile: Shows the color value calculated with the process colors of the target profile
Current: Optimized color value of the process colors
dE76: Expected color difference in DeltaE 76
dE00: Expected color difference in DeltaE 2000
Paper white simulation: Considers the coloration of the substrate for the target color space
Note: It is recommended to activate the Paper white simulation.
Divided color preview: The divided color preview shows how the original color (upper bar), the non-optimized color by means of the profile (left lower square), and the optimized color (right lower square) would look like when printing. The color preview is displayed in true colors on a calibrated and profiled monitor.

Comparison of original color (Reference), non-edited color (Profile) and edited color (Current)

Note: A warning message is displayed below the color preview when one of the three colors is out of the monitor’s gamut.

After editing the measured values, a file with the optimized device and/or measured values is created by clicking on Start.

Note: The Color Editor tool is grayed out if the file loaded under Data Sets does not contain any measured values. Once a single measurement file has been selected, it can be opened in the Color Editor (multiple files cannot be opened simultaneously).

Color Editor Use Cases

Example: Best possible conversion of (spot) colors

Measurement data from spot colors loaded into ColorAnt can be converted into any color space using the Color Editor and ICC profiles. All color spaces including RGB, CMYK and Multicolor are supported.

Note: The Conversion of Multicolor profiles requires an L license.

To convert a spot color to RGB, CMYK or Multicolor, follow these steps:

  1. Load the measurement data file including individual full tone spot colors (for example a spot color library as CxF file) under Data Sets in ColorAnt, select the file and then click Color Editor.
  2. Under Color Conversion Settings, select the desired ICC Profile from the drop-down menu.
  3. The table on the left side fills with the device values. Initially, the device values are identical for Current (DCS) and Profile (DCS), since no optimizations have yet been made.
  4. Select the color you would like to optimize from the table and a Mode under Color Conversion Settings.
    The calculation mode specifies how ZePrA should convert one or more spot colors to the target color space.
  5. Choose one of the three modes described above. Under dE00 Limit, enter the threshold value in DeltaE 2000 from which colors in the table are to be marked with a warning symbol.

  6. The control panel Optimize Output Values shows the device values (Current DCS) calculated with the selected ICC profile. The calculation is always absolute colorimetric.

  7. Now click on Automatic to convert the colors using the selected calculation mode. Alternatively, perform the calculation according to DeltaE76 (dE76) or DeltaE 2000 (dE00). However, these two methods do not include ColorLogics high-quality calculation modes. The device values are displayed immediately after application of the calculation.

    By clicking on Revert the changes can be undone.
  8. The Color Information panel shows the measured Lab value of the color under Reference, the color value calculated with the process colors of the target profile under Profile and the optimized color value under Current. Additionally, the expected color difference is displayed in dE76 (DeltaE 76) and dE00 (DeltaE 2000). Activating the checkbox Paper white simulation takes the coloration of the substrate for the target color space into account. The calculation of the Lab values for Current and the color distance (DeltaE) are performed accordingly.
    Note: It is recommended to activate the Paper white simulation.
    Divided color preview: The divided color preview shows how the original color (upper bar), the non-optimized color by means of the profile (left lower square) and the optimized color (right lower square) would look like when printing. The color preview is displayed in true colors on a calibrated and profiled monitor.

    Comparison of original color (Reference), non-edited color (Profile) and edited color (Current)

  9. If you want to make fine adjustments, manually optimize the percentages in the Optimize Output Values control panel and see the effects directly under Color Information.
  10.  If you are satisfied with the optimization, continue optimizing more colors. Optimized colors are updated directly in the table. With a click on Start the editing is completed using the device values shown under Current (DCS) and the dialog will close. Please note that colors that have not been optimized will only be converted using the normal profile conversion and may therefore not achieve the best possible result.

Specifics

  • If you would like to optimize several or all colors in the table at once, select the desired colors and click on the desired calculation (Automatic, dE76 or dE00).
  • If two or more colors are selected, device and color values are grayed out in the panels Optimize Output Values and Color Information.
  • If a file previously optimized with an ICC profile in the Color Editor is re-opened in Color Editor, the previously used ICC profile is preselected automatically.
  • If you change the ICC profile, typically, the device values have to be recalculated. To do so, activate the checkbox Recalculate DCS values and confirm with OK.

Confirm recalculation of the DCS values

Example: Saving color-converted spot colors to other formats
Spot colors converted with Color Editor can be saved in various color formats supported by ColorAnt and used in other applications.

  •    CxF or CxF/X-4 for use in many modern applications
  •    Adobe Swatch Exchange (ASE) for use in Adobe Illustrator and InDesign
  •    ACO for use in Adobe Photoshop
  •    ICC Named Color Profiles for use in programs that support this special ICC format.

The complete list of supported formats can be found here.

Note: Spot colors converted with Color Editor contain the original color values (Lab or spectral values) and the optimized device values for the selected ICC profile.

Example: Manual Editing

The Color Editor also allows to manually change color patch names or color names, to manually change the measurements and device values associated with a color patch, and add or remove individual color patches. Make the appropriate changes in the topmost control panel Measurement Information.

Under Name change the name of (spot) colors or color patches of test charts.

Under CIE edit the measured values of the color, under DCS edit device values (if present). Typically, DCS values are not available in a pure spot color measurement file.

Using the buttons below the table (Add, Delete), selected colors can be removed or one or more colors can be added. Added colors are placed at the end of the table. A default name and a medium gray are preselected, which can be changed under Measurement Information as required.

Specifics

  • Measurements of profiling test charts often have no name designations. For such measurements, the Color Editor automatically adds an identifier, for example #1 for the first patch.

  • Spectral measurement data can also be edited in the Color Editor. They are then displayed as Lab values with D50/2 degree standard observers. In the final file, however, the spectral values are preserved.
  • If the CIE values of spectral measurements are edited as Lab values, the spectral properties of the color are retained.
  • We recommend not to change or optimize DCS values in test charts if the data is used for profiling purposes.
  • When selecting an ICC profile, typically, the device values don’t have to be recalculated. Deactivate the checkbox Recalculate DCS values and confirm with OK.

Recalculating colors without changing the DCS values

ColorAnt | Edit Primaries

Edit Primaries

Customize options for file processing

Edit Primaries

The Edit Primaries tool allows users to add, remove, and exchange primaries or the paper/substrate in existing measurement data.

In typical print production, adding or swapping ink(s) requires the expense of printing a complete, full size test chart. The Edit Primaries tool simply requires the spectral data of the new ink(s) to be added or exchanged. It also recalculates all overprints based on intelligent spectral color models.

One of the major features of the Edit Primaries tool is the ability to dynamically select the best patches from the data provided. The more complete the data (spectral data is preferred) the more accurate the results.

More complete data improves:

  • Exchange of gradations of the primary color
  • Overprint information, e.g the primary combined with black and secondary colors
  • Spectral data in general, providing the printing sequence information.

This allows creating of new ICC profiles for new color combinations quickly.

Examples for efficiency gains when using the Edit Primaries tool in production:

  • Variance in press condition: The characterization press run is slightly deficient in solid ink density or hue on one or more colors.
    This video demonstrates the procedure with ColorAnt
  • Exchange of paper/substrate: The inks are the same but a slightly different paper is used in production or a specific job.
  • Exchange inks in packaging print production:
  • Create a new set of characterization data that swaps in e.g. Blue for a Cyan or a Rhodamine Red for Magenta.
  • Adjust Printing Sequence: Allows improved overprint calculations. Watch an example here.
  • Flexibility for packaging customers: Create different color variants from a full blown 7 color press characterization data set by deleting channels to create new characterization data sets without printing a new test chart. For example, from an 7C data set (e.g. CMYK+Orange+Green+Violet) build variants for CMYK only, CMY+Violet, CMYK+Orange+Green or other combinations. Ensure that the printing process is stable and use the color combinations you need to fulfill the respective customer orders.
  • Increase CMYK gamut: Adding a 5th, 6th or 7th color to a CMYK printing process.
  • Modify channel names: Reorder channel names without data modification.

Restore last edits: Use Restore to exit the tool without losing any of the changes already made. Click Cancel. ColorAnt will remember the edits made up to this point, and leave the Edit primaries tool. Restore these edits after you return by clicking the Restore button. You can now continue your work where you left off. For example, if after a few edits you notice that you forgot to load a required file into ColorAnt, you can exit the tool, load the file and return without having to make these edits again.

Restore last edits: Use this function to exit the tool without losing any of the changes already made.

Click Cancel. ColorAnt will remember the edits made up to this point, and leave the Edit primaries tool. Restore these edits after you return by clicking the Restore button. You can now continue your work where you left off.

For example, if after a few edits you notice that you forgot to load a required file into ColorAnt, you can exit the tool, load the file and return without having to make these edits again.

Define Primary Information

Linearize new channels using ISO 20654 (SCTV): The checkbox becomes available when a new channel is added, or if reference data without measurement data are loaded. When checked the gradients of the newly added channels are linearized according to the ISO 20654 (SCTV) standard. If channels of another data set are selected and the checkbox is selected, all channels are linearized according to ISO 20654 (SCTV). Otherwise, the original gradations of the loaded colors will be used.

Search: Allows searching for specific colors in large color libraries such as Pantone®. It is available in the context menu by clicking the eyedropper when replacing a color.

Exchange a Primary Color

One of the main features of Edit Primaries is the exchange of primary colors creating a new set of characterization data.

Procedure:

  1. Load the measurement data of the test chart to be edited in ColorAnt, then load the data set containing the measured new primaries, including gradations of the primaries and overprint information.
    A sample of a reference file for CMYK plus one spot color is included with ColorAnt. The wedge Spotcolor-CMYK+X-v1.txt (shown as Red spot color in the screenshot) is located under File/Open Predefined. Use the tool Export Chart to generate a printable wedge.
  2. Click on the measurement data to be edited (to select it) and click on Edit Primaries.
  3. Exchanging a primary: Click on the eyedropper icon of the color to be exchanged (see screenshot demonstrating an exchange of Yellow).

  4. Select the new primary from the second data set loaded in ColorAnt. To do so, click on the channel containing the new primary. Selecting a color from another channel of the same data set is also possible. In Edit Primaries the Lab value of the new primary will be shown allowing you to check immediately if the changes have taken place. If the imported measurement data are spectral data the star will be highlighted.

  5. If two or more primaries are added from a single data set containing overprints of these primaries, then these measurements can be used by ColorAnt and the checkbox Adopt Secondaries will be enabled.
    Note: Adopt Secondaries is only enabled if secondary colors are available in the selected data set. When moving the mouse over the text a tooltip will show the selected color combinations and the associated data sets.
  6. If no measurement data of the new primary is available, Lab values can be entered in the numbers box (however, calculations will not be as exact as with spectral measurement data). This will be visualized by a gray star icon.
  7. When complete click Start and the data will be modified and shown in the Data Sets section of ColorAnt. Save the new data with File/Save as to be used for other tasks, for example, creation of ICC profiles with ColorLogic CoPrA.
  8. To check the exchange of primaries, use the Compare tool to verify the data.

Specifics

  • If a solid color is used to replace a primary color but does not contain any gradation values, ColorAnt uses the gradation behavior of the original primary color.
  • Edit Primaries dynamically selects the best patches from the data provided. The more complete the data (spectral data is preferred) the more accurate the results. The exchange of primaries will improve when providing gradations of the primary color and  overprint information, such as the primary with black overprints or secondaries.
Adding Channels

Note:  To add channels a ColorAnt L license is required.

Procedure:

  1. Load the test chart measurement data and load the secondary file with the measured primaries, gradation and overprint information into ColorAnt.
  2. Select the measurement data you would like to edit and click Edit Primaries.
  3. Click on Add Channel. A new channel with default gray Lab values and the channel name Auto is added.
    Note: The Auto entry will take the channel name from the second data set.
  4. Click on the eyedropper icon of the new channel and select the new primary from the second data set. Click on the channel to import the data.

    Example of a 5th color (Red) being added to an original CMYK data set.

  5. To rename the channel click on the pencil icon and enter the desired name in the appearing window Edit Primary Name.

    Important:     Define the Original Printing Sequence and the Edited Sequence. This is especially important when a new ink is added as it can be added as the last ink or placed in between other primaries.
  6. If two or more primaries are added from a single data set containing overprints of these primaries, then these measurements can be used by ColorAnt and the checkbox Adopt Secondaries will be enabled.
    Note: Adopt Secondaries is only enabled if secondary colors are available in the selected data set. When moving the mouse over the text a tooltip will show the selected color combinations and the associated data sets.
  7. Click Start and the new 5 inks data set will be generated. ColorAnt will calculate modified measurement data which can be found under Data Sets. Save this file under File/Save as for further usage, e.g. creation of ICC printer profiles in CoPrA.
  8. To examine the new data set, use the View tool and select the tabs 2D, 3D, SpiderWeb and TVI  to check that all colors including overprints have been added correctly. The TVI curves of the 5th channel can be edited further by using the Tone value tool and/or other tools like Smoothing. Finally, CoPrA can be used to build a 5 channel printer profile.

Adopt Secondaries: Allows secondary color values to be used additionally. The option is only enabled if secondary colors are available in the picked data set and at least two colors are exchanged. A tool tip indicates the selected overprints and the associated data sets. The option can be disabled if the measurement overprints are not suitable for the given data, in which case Edit Primaries will calculate the overprints itself.
Using color overprints can improve the accuracy of the rendering and calculation of the spectral color model.

Linearize new channels using ISO 20654 (SCTV): This function allows the gradients of newly added channels to be linearized according to the ISO 20654 (SCTV) standard. The checkbox is available when a new channel is added, or when reference data are loaded without measurement data. If channels of another data set are selected and the checkbox is activated, all new channels are linearized according to ISO 20654 (SCTV). Otherwise the original gradations of the loaded colors will be used.

Removing Channels

Note: A ColorAnt L license is required to remove channels.

  1. Load and select the measurement data of a test chart and click Edit Primaries.
  2. Disable the checkboxes in front of the channels that need to be deleted and click Start. The information area of the Edit Primaries tool displays the channels of the resulting data set.
  3. The new data set will be reduced to the channels that have been enabled. Please be aware that this is a Multicolor file and may only be used in ColorLogic CoPrA if a Multicolor license is loaded.

Note: Edit Primaries can be used to extract individual channels from complete test chart measurement data by removing all other channels. Just leave the checkbox of the desired channel activated and deactivate the checkboxes of all other channels.

Reordering Channels

The channel order can be changed within a file without changing the measurement data itself. For example, if you have added the additional channels Orange and Green to a CMYK data set you can change the order to CMYK+Green+Orange afterwards.

Simply click on the eyedropper icon and select Orange for Green and Green for Orange from the same measurement data file. This will change the channel order without changing the measurement data. If only the channel order has been changed, this is indicated by the name ChannelOrder in the file name.

Note: The channel reordering feature in Edit Primaries and the Link tool Merge by Channel Name can be used to prepare Multicolor measurement data from different origins. For example it allows to combine the four separate 4 color Esko Equinox files to a 7 color Multicolor data set to be used for profiling in CoPrA.

Creating new characterization data on existing wedges

The Edit Primaries tool allows the assignment of new color values to device values (DCS values) which do not already contain color values. Thus, new characterization data can be created based on CxF/X-4 data, existing wedges of primaries, the input of Lab values or other characterization data sets without the need to reprint test charts.

Procedure:

  1. Open a reference file (for example IT8/7-4) and, if available, measurement wedges or existing characterization data of test charts containing the desired colors.
  2. Select the reference file, click on Edit Primaries and use the eyedropper tool to choose colors from the pool of measurement values.
  3. Alternatively, fill in the Lab value if there isn’t other data available. The best results are achieved using spectral values, wedges or information on overprints.
  4. If two or more primaries are added from a single data set containing overprints of these primaries, then these measurements can be used by ColorAnt and the checkbox Adopt Secondaries will be enabled.
    Note: Adopt Secondaries is only enabled if secondary colors are available in the selected data set. When moving the mouse over the text a tooltip will show the selected color combinations and the associated data sets.
  5. If measurement values are assigned to all primaries and the paper white, click Start.

Note:

  1. The integrated progress bar shows the status of the calculations. With complex mathematical calculations, especially with large test charts and many channels, you are always informed how long these can still last.
  2. When extracting measurement data containing overprint information with black from CxF/X-4 files (so-called full characterisation), you should note that no black gradient is stored in CxF/X-4 files. If you want to edit a black channel with gradient in Edit Primaries, you should use the black gradient from another measurement file and not from the CxF/X-4 file.

Define Substrate/Paper White

Define Substrate/Paper White

Minor changes in paper color do not affect the full tone of the primary colors. In this case, the paper color can be replaced with a similar paper color of an existing dataset.

However, significant changes in paper white affect the entire color space. Major changes in paper white also have a strong effect on the primary colors.

If the white point changes significantly, it can be (re-)measured directly from within the Edit Primaries tool. This measurement data can then be used to correct the white point of the selected dataset. The corrected white point is then applied to the entire measurement data keeping the print characteristic intact. (see instructions below).

Note: If you just want to change the white point use our dedicated White/Black Correction tool.

Replacing the paper color with data from an existing dataset

  1. Load the test chart measurement data and load the secondary file containing information of the measured paper white into ColorAnt.
  2. Select the measurement data of the data to be edited and click Edit Primary.
  3. Click on the eyedropper icon of the Substrate/Paper white and select the new paper white from the second data set. Click on the name of the data set to import the data.

  4. Alternatively, if no measurement file of the new paper white is available, the new values can be entered in the number field as Lab values. However, this is not as precise as working with spectral data.
  5. Click Start and the data set will be modified. The modified measurement data can be found under Data Sets. Save this file under File/Save as for further usage, e.g., creation of ICC printer profiles with CoPrA.

Direct measurement of the white point

Proceed as follows to measure and adjust the white point:

  1. Load the measurement data to be corrected and open the Edit Primaries tool.
  2. Click on the eyedropper icon and select the option Measure.
  3. The Measure Tool opens with the preselected chart for measuring the paper white with a single patch.
  4. After the measurement, the new white point data is transmitted back to the Edit Primaries tool and is applied to the entire measurement data keeping the print characteristic intact.

Note: The white point measurement is also listed under Data Sets.

Define the Printing Sequence

Define the Printing Sequence

The Printing Sequence defines the order in which the colors are printed on top of each other and can be set independently of the channel sequence. When primary colors are exchanged or added, overprinting colors can be correctly calculated by specifying the correct printing order. By changing the print sequence, you can also check whether a changed sequence increases or decreases the gamut.

The printing sequence can be changed by dragging and dropping color symbols

Example: There is a difference in color when a red is printed on a yellow or vice versa. Users can set the print order independently of the channel order so that the channel order is maintained, for example as CMYK, even if the print order is KCMY.

Procedure:

  1. Load a measurement file under Data sets, preferably with spectral data, and open Edit Primaries.
  2. The initial print order, represented as the Original Sequence, of a loaded data set corresponds to the channel order. Change the Original Sequence by clicking on a colored icon and moving it to the desired position.
    Example flexo printing: The colours are usually printed from dark to light, whereas the channel sequence implies a different arrangement.
    Note: When an edited data set is reopened, the Original Sequence reflects what has been done and saved the last time.
  3. Edited Sequence specifies the order of the colors in which they are to be printed.
    Note: If you do not need to change the print order, make sure that the edited order is the same as the original order.
  4. After you are done click Start and the data set will be modified. The modified measurement data can be found under Data Sets.
  5. Save this file under File/ Save as for further usage, e.g. creation of ICC printer profiles with CoPrA.

ColorAnt | Rescale

Rescale

Recalculate data to a different color chart

Rescale

Overview

ColorAnt offers the option of calculating large test charts that can be used for profiling from small test chart measurement files. In some printing processes, (e.g. flexo printing on uneven materials) it can be challenging to achieve artifact-free printing of a large test chart. The procedure of placing several small test charts, e.g. ColorLogic Reprofiler strips on one page, measuring these, averaging them in ColorAnt and then scaling up to a large test chart with the Rescale tool is an effective approach to measuring large size charts.

Procedure:

  1. Select the measurement file that you want to scale up and click on the Rescale button.
  2. Select the desired test chart layout from the drop down menu to which the measurement file should be scaled up.
  3. When you have an ICC printer profile (reference profile), which approximately describes the standard to be printed, select the printer profile by checking the option Use characteristics of a reference profile. 
If the profile is not available, do not activate the checkbox.
  4. Click on Start and ColorAnt will calculate and interpolate the missing color patches from your small chart and create the desired chart layout.
  5. Save the scaled up measurement value file as a new file with File/Save as.

Note: Missing color patches are automatically supplemented when scaling to other charts. Missing color patches (e.g. from overprinting colors that are missing in small charts) can be assessed better with the help of a reference profile.

In reverse, you can also use the Rescale tool to extract the color patches required for the Fogra/Ugra-Media Wedge V3 from a measured large ECI2002 or IT8.7-4 test chart. ColorAnt uses the color patches from the available measurement file 1:1 in the new chart layout. This enables you to produce your own media wedge reference files for verifying printed proofs very easily.

Note: The chooser shows only those test charts that fit the color space of the selected file. E.g. in case a CMYK measurement file has been selected only the CMYK test charts are shown including those delivered with the software and those manually added (marked as Custom). If you wish to add and use your own custom reference files in the Rescale tool or  when opening via File/Open Predefined save them in the Documents/ColorAnt/Wedges folder.

Using the Automatic

A specific sequence in the working method is recommended when preparing measurement data. First clean up redundant color patches in the measurement file, then correct faulty measurement values and finally smooth the measurement data. This sequence is automatically executed by using the Automatic function.

Procedure:

  1. Load measurement file by dragging it onto the Data Sets area or using File/Open.
  2. Click on the Automatic button and on the Start button in the dialog which then appears.
  3. You can follow each step in History and view it individually there (if you have the View dialog open) or undo it.
  4. Save the optimized measurement file as a new file via File/Save as. Use the optimized measurement file e.g. in profiling software like CoPrA to create high-quality ICC printer profiles.

Note: Measurement data is saved in some ICC printer profiles (e.g. CoPrA always saves the measurement data in the calculated ICC profile). Extract the data from the corresponding ICC printer profile simply by dragging the ICC profile onto the Data Set area in ColorAnt.

The Automatic function calculates from the loaded data if either an averaging of multiple files is needed (in case multiple files with the same amount of patches have been loaded) or if redundancies, correction and smoothing shall be applied. This is how the Automatic feature works: It checks for Redundancies in the measurement data first, corrects bad measurements and applies Smoothing to a lesser extend (50% slider setting with no protection of highlights). This leads to optimized measurement data leaving the characteristics of the print closest to the original and thus to better profiles in the end. The screenshot below shows the settings the Automatic feature uses.

Note: For Flexographic measurement data we suggest to manually optimize and smooth the data as the Automatic feature would smooth out any bump curves, too.

ColorAnt | Tone Value

Tone Value

Correct measurement data to a specific set of curves

Tone Value

The Tone Value tool allows the correction of measurement data as well as the calculation of RIP compensation curves based on specific targets (e.g., G7®, ISO 20654 SCTV).

There are three different ways to ensure tone value correction is incorporated properly into measurement data. The curves created in this way are the final cut-back, compensation, calibration curves.
Note: It is not recommended to bend measurement data to a preferred standard without having printed so or without applying an appropriate RIP compensation curve.

Correction according to a tone value curve of an ICC profile:
Specify a profile and the measured values or the RIP compensation curves are adjusted to achieve the same tone value increase curves as those of the selected profile.

Correction according to a profile

Note: Depending on the loaded measurement data only ICC profiles fitting the color space are shown (e.g., CMYK or multicolor. In this example a 7 inks multicolor profile is selected).

Correction according to:
Tone value curves are calculated to match the requirements of G7® Gray Balance or ISO 20654.

Correct Measurement data and RIP curves to given standards

G7® Gray Balance: The tone value curves are calculated to correspond to the gray balance conditions of the G7® method. The aim of the G7® method is to adjust the CMY curves in such a way that they result in as neutral a gray hue as possible with defined lightness over the entire gray balance.

ISO 20654: This method is based on colorimetric linearities and can be used instead of density calculations for spot colors. It can also be applied to CMYK and ensures that the gradations of all primary colors are colorimetrically linear. This can be checked in the View window under TVI or Curves.
Note: Density-based methods like Murray Davis do not work well with non-CMYK colors. The IS0 20654 method (also known as SCTV, Spot Color Tone Value) is an alternative method for handling the tone values of spot colors.

G7® + ISO 20654: G7 is defined to work with CMYK only. However, it is possible to apply the G7® method to the CMYK parts of a Multicolor measurement file and the additional (Multicolor) channels will be corrected according to ISO 20654. The G7® calibration method ensures that the CMY curves reach a neutral gray of defined lightness values throughout the entire gray balance curve.

ISO 20654 (Multicolor): Adjusts the Multicolor channels according to ISO 20654 and leaves the CMYK channels untouched. This is useful when the CMYK parts have been calibrated according to other standards, like PSO density curves or G7® and only the additional Multicolor channels need to match ISO 20654 (SCTV) requirements.

Correction according to TVI targets:

Manual editing of each channel allows predefining the increases in tone value to be incorporated in the measurement data.

This feature works for CMYK and multicolor color spaces. Depending on the data that was loaded into ColorAnt, additional or fewer channels are displayed.

Protect Lights (%): Leaves the highlights untouched when applying any of the three correction modes.
Specify the percentage up to which the highlights are to be protected. Review the measurement data to ensure a clean transition between the protected and unprotected area. This feature is especially helpful for Flexo printing as it avoids overcompensation of dot gain in the highlights.

Save Compensation Curves as: TVI correction curves can be saved as Text, ACV or XML files. Select None, if the curves are not to be saved.

Important: These curves have to be used in the RIP to implement the corrections. Further information can be found below in the chapter Combining Print Characterization and Compensation Curve Calculation.

Text: CGATS-compliant ASCII text. Used for direct import into RIP software or prepress workflows, e.g., HYBRID CLOUDFLOW.
ACV: Saves curves in the Photoshop ACV format.
XML: Saves curves as XML files according to ISO 18620.
Note: These curves are automatically saved in the folder /Users/USERNAME/Documents/ColorAnt/Linearity on macOS systems or C:/Users/USERNAME/Documents/ColorAnt/Linearity on Windows PCs. They can then be used in either Adobe Photoshop or any external RIP software that supports the ISO 18620 standard. ZePrA also supports the exported ACV or XML curve formats in the Gradations dialog.

Correction of Tone Value Increase Curves through Presetting

With the method Correction according to TVI targets, you can edit and smooth tone value increase curves, add or remove individual control points, and transfer curves from one channel to another. You can also compare the original and modified curves. You can save curves and apply them to other data and channels. The tone value curves are displayed according to the calculation method selected in the Settings.

Apply curves to other data or channels

Procedure:

  1. Open the measurement and click on Tone Value. The channel names correspond to the names of the measurement file or are determined automatically by ColorAnt if the channel names are undefined.
     
  2. To transfer a curve shape from one channel to another, simply select the desired curve from the drop-down list of the channel to be changed, for example Cyan, to apply the Cyan curve to the Magenta (original) channel. You can also apply a previously saved (and possibly optimized) curve from another data set to the Magenta (original) channel, here for example the Magenta Tonwertvorgabe curve.
  3. After curve transfer, you will see the curve shape of the new Magenta curve (colored) and the original Magenta curve (grayed out).

  4. To make further (manual) corrections to a channel, such as Smoothing, or to remove control points, or to change individual values, click on the pencil icon or select Edited from the drop-down menu. The Custom Tone Values – Edited window opens. For information on how to make manual corrections, see Custom Tone Value – Edited below.
  5. To undo changes, select (in this example) the entry Magenta (Original) from the drop-down list.

When you have finalized your edits, apply them to the measurement data by clicking Start.

Custom Tone Value – Edited

ColorAnt’s Custom Tone Value feature is specifically designed for manual corrections such as smoothing, adding or deleting points or changing individual TVI values. In addition, save custom curves and apply them on other channels and data.

Procedure:

  1. Click on the Smooth button to smooth the curve. Only a few fulcrums are displayed after smoothing; ColorAnt does not delete​ any original fulcrums but helps to better optimize the data by reducing the number of values. Apply the corrections on the measurement data and all fulcrums will be adjusted to fit the smoothed curve.
  2. In order to add any number of additional ink values, click on the Add button. Navigate to the new empty entry that will appear in the table and type in the desired Ink Value and the Increase value in dot percentage required. Apply the changes by hitting the tabulator or the enter key on the keyboard. The curve will be immediately updated.


    Note: The original curve will be displayed in gray as a reference.

  3. Change any of the existing Increase values in the table by simply selecting an entry and changing the numbers.
  4. To delete an Ink Value, select the desired entry in the table and click Delete.
  5. Save the curve for later use. Click on Save as and enter a name for the curve in the appearing dialog.

  6. To apply the manual editing, click on OK and return to the Tone Value dialog. The edited curve will be marked as Edited.

Combining Print Characterization and Compensation Curve Calculation

  1. The ColorAnt TVI correction can be used to combine RIP compensation curves and print characterization in a single print run.
  2. Print a test chart for characterization/linearization with the RIP in linear mode
  3. Measure the test chart (These measurement data represent the linear print process)
  4. Smooth the measurement data (with the Smoothing tool)
  5. Open the Tone Value TVI correction tool
  6. Choose Correction according to a tone value curve of an ICC profile and select the target curve for the printing process
  7. Export the compensation curve in the format the RIP can read (e.g., Text for HYBRID Cloudflow)
  8. Apply the TVI correction to the measurement data (the measurement data represent the compensated print)
  9. Load the compensation curve into the RIP

The corrected measurement data can be used, for example, to create a proofing profile that represents the compensated printing process instead of the linear printing process.

ColorAnt | Averaging

Averaging

Average several data sets into one data set

Averaging Data Sets in ColorAnt

Overview

The tool Averaging can be used to average several measurement files of the same test chart and combine them to form a data set. For most data sets, the Auto method is recommended.

The methods for averaging the data sets are the same as in the Redundancies tool.

Auto: Different methods are used depending on the number of color patches. It is therefore quite possible that some color patches are processed with a different method than others. If there are two identical color patches with differing measurement values and one of the measurement values is recognized as an outlier, this method automatically selects the plausible color value.
For more than three color patches, the Weighted or Median methods are used. If there are a large number of measured values, both the Median and the Weighted methods consider values that are far apart to a lesser extent for averaging.

As the most intelligent method, Auto is preferable to the other methods.

Arithmetic: For the arithmetic averaging of values of several color patches, i.e. the average of the measurements (if, for example, only two color patches are to be averaged).

Median: Is a statistical method and denotes a boundary between two halves. The median is the “middle value” of a sorted list of numbers. Half of the numbers in the list are smaller and the other half of the numbers are larger than the median.

Weighted: Calculates a weighted mean value, i.e. a mean value to which some values contribute more than others. Outliers can be considered to a lesser extent for averaging.

Apply redundancies correction after averaging: This function is activated by default and useful if a test chart contains redundant patches, since these could still be different in the averaged file. This function saves you the extra step of using the Redundancies tool after averaging.

Procedure

  1. Load the measured values you want to average and select them in the Data Sets window. Make sure that the number of color patches is identical in all selected measurement files, otherwise you cannot use the Averaging function directly.
  2. Select the tool Averaging from the sidebar.
  3. The methods described above are available for averaging. The Auto method is selected by default and recommended for most cases.
  4. Apply redundancies correction after averaging. This function is enabled by default and saves you the extra step of applying the Redundancies tool after averaging.
  5. After clicking Start, the selected measurement files are merged to an averaged file (Average.txt).
  6. The averaged file can be saved as a new file using File/Save As.

ColorAnt | Brightener

Brightener

Correct Data for Optical Brighteners

Correct effects of optical brighteners

Paper manufacturers often use optical brighteners to make the paper look brighter. Unfortunately, visual validations will take place under different lighting conditions in comparison to the measuring device. Under standard D50 lighting conditions, the paper appears brighter and measured values usually appear a very bluish white without actually being brighter. The problem is validation under standard lighting booths, which deliver a questionable match with the D50 illuminant.

Spectrophotometric measurements with the D50 illuminant lead to issues when using the profile, in particular with validation under standard lighting, because the excessively blue proportion of the paperwhite is compensated in order to achieve a neutral gray. This can be problematic and lead to an overly yellowish gray balance or paper simulation during proofing.

Note: Due to the introduction of the ISO standard for improved D50 simulation in standardized lightning booths (ISO 3664:2009) and the M1 measuring condition (ISO 13655:2009), the effects are less dramatic as in the past. The effect of optical brighteners is now simulated much better in standardized lightning booths and fits more to the results of the measurement devices. Nevertheless, there can still be significant visual differences.

To remove this effect, the Brightener tool can be applied to measurement data. Spectral measurement data (remission data) is required for best results. The first step of optical brightener correction is the analysis of the remission curve of the paperwhite to determine whether the paper contains optical brighteners or is merely a blue-colored paper. The second step is correction, which only takes place if an optical brightener has been detected. The correction can be adjusted via a slider control and at a 100% setting, a similar result will be achieved as if the paper were measured with a UV cut filter.

Using the Brightener tool results in modification of the spectral values of the paper white. It is then incorporated into all areas of the measured value file(s) that are affected by the optical brightener. As a result, the lighter color values will predominantly be affected whereas the shadows and the highly saturated colors will either less or not at all affected. If the measurement file is available with spectral remission values ColorAnt will preserve the spectral data.

Note: For optimal results apply the Brightener tool on spectral measurement data (remission values). Correction of the Lab values will work as well with non-spectral measured values, but a more basic compensation model will be used.