ColorAnt | Evaluate

Evaluate - Proof Evaluation

Evaluation of Proof Measurement Data

Evaluate – Proof Evaluation

Evaluate can be used to check whether the proof measurement data from a media wedge fulfills the requirements for a contract proof according to ISO 12647-7 or a validation print according to ISO 12647-8. A fully-detailed report can be created with a pass/fail indicator.

Note: The Proof Evaluate tool supports all color spaces including Multicolor and spot colors. It is a powerful addition to the proofing feature introduced in ZePrA 8, as it allows you to use the reference files of the dynamic media wedges created by ZePrA for proof evaluation.

The Evaluation tab immediately shows the categories related to the chosen standard, the deltas to the reference, and a score with either a ✓ (passed) or an ✕(failed).

An overall score indicates if the proof has passed or failed.

There are two ways of selecting your reference:  

  • Choose reference data: This drop-down menu contains all data loaded under Data Sets that fit the selected proof measurement data as a reference, which means the number of patches and the color space must match. Select the reference that you want to compare with the selected media wedge measurement data. If dynamic media wedges were used in ZePrA, the corresponding reference data can be used for the proof evaluation in ColorAnt.

    Using reference data from ZePrA:
    1. Open the reference file of the ZePrA configuration in ColorAnt. It is located in ZePrA’s Report folder of the corresponding queue.
    2. Select Measure to measure the media wedge in the proof printout
    3. Open the resulting measurement file and click the Evaluate button.
    4. Select the original reference file from ZePrA under Choose reference data in the Proof Evaluation window.
     
  • Choose reference ICC profile: This drop-down menu contains all ICC profiles that fit the selected proof measurement data as reference in terms of the same color space. Choose the reference ICC profile that you want to compare with the selected media wedge measurement data.
    Note: The ICC profile is used to create virtual reference values. Depending on the accuracy of the ICC profile, the quality of the reference data can vary from very exact (e.g. CMYK profiles created by CoPrA) to less exact (e.g. small Multicolor profiles).  

Evaluation method: Select a method to either evaluate a Contract Proof according to the ISO 12647-7 standard or a Validation Print according to the ISO 12647-8 standard.

ISO 12647-7: For the evaluation of a binding contract proof use this method. 

ISO 12647-8: Checks the conformance of printing systems that produces a hard-copy validation print, directly from digital data, which is intended to simulate the expected appearance of material printed per a characterized printing condition.

Note: Recently, other visualizations of the final printed product have found a place in the printing/proofing workflow because designers and print buyers prefer not to go to the expense of using an ISO 12647-7 compliant contract proof any earlier in the process than necessary. In many situations, participants in the workflow require a hardcopy visual reference of lesser quality than a contract proof. In the past, those prints varied widely in quality and were often referred to as design proofs, concept proofs, layout prints, etc. That quality level is here being referred to as a validation print.

Report

The available input fields depend on the selected Evaluation method. Enter the required information according to the selected ISO standard.

Save Report: Choose the file location and the format for the report (PDF, HTML, XML).

The report contains all the information that you have entered, the summary from the evaluation dialog, a list of all patches with their names or IDs, the device color space, the Lab reference values, the Lab measurement value and the delta.

ZePrA | Apply Photoshop color corrections to PDF files

Apply Photoshop color corrections to PDF files

In some applications it is not possible to use measurement based DeviceLink profiles. This is true, for example, if a customer brings print data and a print that should be as accurate as possible in the production run without a correct proof. If you view the print data on a monitor with a soft proof of the print standard for the production run, clear deviations from the print that you have brought with you can become visible.

In this case you could either print outside the standard and try to recreate the default – either by making gradation corrections in ZePrA or by using the capabilities of the printing press – or print inside the standard by applying Photoshop corrections to the PDF file. The latter has the advantage that you can proof the color-corrected data according to the standard and have it approved by the customer. This procedure requires an experienced Photoshop user and CoPrA’s Editing tool.

For a test with production data the demo version of the programs can also be used. To do this, meaningful objects must be combined from the existing PDF data into one file in Photoshop and combined with CoPrA’s test chart (EditTarget). This test file is then corrected under softproof conditions on the monitor. The edited image is imported into CoPrA and the corrections are taken into account in the created DeviceLink profile.

Then the DeviceLink profile can be used in ZePrA to correct the color of the original PDF data. If necessary, the corrections can be approved by the customer on a proof before printing. The printer can work as usual according to standard and reach the proof reliably.

The individual steps are described in detail in the chapter How to create DeviceLink profiles with edited charts in the CoPrA Help.

ZePrA | Proofing

Proofing

Color-consistent simulation of the printing result

Proofing

ZePrA’s sophisticated technology – e.g. the quality of DeviceLink and SmartLink profiles and the spot color rendering of its advanced spot color module – can be used for proofing as well. This is especially useful as many RIPs do not support CxF/X-4 data and SCTV calibration nor have a spectral color prediction model for spot color rendering.

The Proofing tab under Configuration contains all Media wedge settings and the Proofing Information label.

Media Wedges

Two types of media wedges can be used:

  1. Media Wedge in Simulation Color Space: Can be used to determine the accuracy of the proof. This media wedge is converted based on the color management setting defined in the various configuration tabs.
  2. Media Wedge in Proofer Color Space: Allows using a second media wedge that is not color managed. It must be in the color space of the proofer and can be used to determine the stability of the proof printer.

Choose a Media Wedge.The media wedge is added outside the document’s media box to verify the proof. This can either be a dynamic or an external media wedge.

Dynamic Media Wedge: Uses the color space information of the simulation color space and dynamically adds all spot colors of the documents to be processed. The required reference files for measuring the wedges are created on-the-fly by ZePrA. They will be saved in the Folder for Report and other Data folder of the proofing queue that has automatically been set up by the Auto Setup Wizard.

The reference files for dynamic media wedges contain both the device values (DCS values) and the target Lab values. The target Lab values are also calculated for the spot colors of the job and incorporated into the reference file in addition to the color values of the document color space. This is done according to the settings under Configurations > Options (solid tone only or gradation values as well) and Configurations > Spot Colors.

The measured values obtained can then be immediately compared to the target Lab values (e.g. in ColorAnt/Compare). Use these reference files in appropriate tools, such as ColorAnt’s Measure Tool, for measuring.

Note: Reference files are not created when the report folder Folder for Report and other Data is missing. If you convert a normal queue by enabling proofing, you must create this folder manually so that a reference file can be created. If this folder is missing, no reference file can be created.

Reference files are created for each job in the queue and named as follows:

Jobname_DynamicMediaWedgeReferenceSource
Jobname_DynamicMediaWedgeReferenceTarget

If dynamic media wedges are selected for source and target color spaces, two reference files for each job will be created.

Note: If the same job is run again, the reference file will be overwritten. This means that if the spot color patches are changed under Options, a modified reference file is saved, and any previous conversion with the reference file with a different number of patches is lost.
The use of spot colors for the dynamic media wedge can be defined under Options 

Media Wedge from File: Can be media wedges such as the FOGRA, UGRA, Idealliance* or other media wedges. For external media wedges, the corresponding reference file is required to measure the printed wedge. Measurements can be done with any proof evaluation software or with ColorAnt’s Measure Tool.

*The IDEAlliance ISO 12647-7 Control Wedge 2013 is included in ZePrA and available under /Users/Shared/ColorLogic/MediaWedges (Idealliance ISO 12647-7: 2013, 3-Row Digital Control Wedge ® is a registered trademark of the Idealliance).

Note: A separate ColorAnt license is required to use the measurement and comparison features.

Proofing Information: Enabling this checkbox will add text information which are in accordance with ISO 12647-7 such as information about the job, date and time, conversion settings and the software used. The information that will be added to the converted file can be verified and edited in the text field. For editing switch to Custom.

Position: The two media wedges and the proofing information label can be positioned independently on the converted document. For each of these 3 elements, the user can specify where it should be placed. Positioning options are: Automatic, Bottom Margin, Right Margin, Top Margin, Left Margin. The elements are placed outside the media box of the document according to this setting. This results in an enlarged media box in the converted document. Automatic is suggested as default settings for all 3 elements to make sure that they are placed together on the converted job.

Options: General settings and settings for Dynamic Media Wedges can be defined unter Options.

Media Wedge Options

General

Font Size: Defines the font size used for the proofing information label in points.

White Space: Allows the placement of margins on media wedges by entering a user-defined distance in mm. By default a white space of 15 mm is added. This ensures that enough white space is added on the left and right of the placed media wedges which some instruments need for correct measuring. The White Space margin applies both to external and dynamic media wedges.
Note: If the external media wedge already has a margin, we recommend entering 0 mm as White Space. As a rule of thumb the white space in millimeters for dynamic media wedges should be at least the size of the Patch Width. The white space of the Media Wedge in Simulation Color Space is color managed whereas the white space of the Media Wedge in Proofer Color Space is not.

Place on every page: For multi-page PDF files media wedges can be placed on each page. By disabling the checkbox media wedges will be placed on the first page of the PDF only.

Dynamic Media Wedges

Defines the Default Chart Width, the Patch Width and the Patch Height of the dynamic wedge.

Gap Size: To separate individual patches. Select the width in mm.

Patch Distribution: Defines the distribution of patches on the media wedge.

  • Randomize: Color patches are distributed randomly.
  • Normal: Color patches are distributed as specified in the reference file.
  • Sorted: Color patches are sorted from light to dark.

Patches per Spot Color: Defines whether spot colors are to be used in the dynamic media wedge and, if so, whether tints are to be used.

  • None: No spot color is added to the dynamic wedge.
  • Solid Tone: Only the solid tone of each spot color in the job is used in the dynamic wedge.
  • 3 Patches: Uses the following patches for each spot color: 100%, 70%, 40%.
  • 5 Patches: Uses the following patches for each spot color: 100%, 70%, 40%, 20%, 10%.

Exclude Colors from dynamic wedges: Spot colors are used in documents for various reasons besides printing purposes, e.g. to illustrate the DIE cut lines, or varnish, braille or other non printing elements. Obviously, those colors are not to be used in the dynamic media wedge. To avoid using them in media wedges, create a library (or more if needed) containing all spot colors to be excluded and select it (or them) from the list under Exclude Colors from dynamic wedges. This list contains all spot color libraries managed by ZePrA. Enable the checkboxes of only those libraries which contain the colors to be excluded.

The selected libraries containing the colors to be excluded are also applied to spot colors of external media wedges. Typically, if the Document Color Space is Multicolor, ZePrA assignes the channels of the Document Color Space to the channels of the media wedge. This is intended in most cases, e.g. if a 7C media wedge with generic channel names is used for a 7C Document Color Space in such a way that the channels are associated. However, this is not intended in case a spot color White is to be used as 5th channel and the 5th channel in the Multicolor profile of the Document Color Space is called Orange (for example). To retain the white spot colors an exclusion library which contains White as non-printing color can be selected.

ZePrA | Troubleshooting

Troubleshooting

Detect and resolve errors

Overview

To prevent errors and problems when processing files, ZePrA checks configurations and hot folders as well as settings and licenses.

If errors or problems are detected, an error message appears in the lower left of the ZePrA window.

If you click on this message, the error is displayed. If several errors are detected, a list of all errors is displayed.

Another click on the corresponding message opens the Troubleshooting dialog, which lists possible solutions to the problem found, which can then be applied to resolve the error.

Causes of errors

Errors can occur, for example, if certain profiles (or spot color libraries) are used in a configuration without embedding them in the configuration, and this configuration is then transferred to a computer on which these profiles (or spot color libraries) are not available. It is then not possible to process files with this configuration.

But certain combinations in the settings can also cause problems.

ZePrA therefore checks:

  • Configurations
  • Settings
  • Hotfolder (all required folders must be available)
  • Profiles (all required profiles must be available on the computer)
  • Gradation curves (all required gradation curves must be available on the computer)
  • Licenses (all required licenses must be available on the computer, depending on the job this can be SmartLink, Multicolor, spot color or SaveInk licenses)
  • Spot color libraries (all required spot color libraries must be available on the computer)

Troubleshooting

In the Troubleshooting dialog, the identified problem is described and options for solving the problem are suggested.

Some problems can occur in multiple configurations and can be solved immediately for all affected configurations, for example, when using the Perceptual Rendering intent in combination with SmartLink.

Click on the message to open the Troubleshooting dialog. Here, by selecting the Solve the issue automatically checkbox, you can switch all affected configurations to Standard Compression without having to change each configuration individually.

CoPrA | DeviceLink Iterate

Iterate

Improve DeviceLink profiles

Iterate

Overview

An existing DeviceLink profile can be optimized based on measured color values by using a test chart of your choice (can be created with ColorAnt/Custom Chart, see video turorial below). The iteration​test chart needs to be converted from source to target profile using the original DeviceLink profile and printed on the target printer. The measured color values of the printed test chart are then used to improve the conversion in order to achieve lower color differences and a more accurate reproduction of the source color space. Based on the measured values, it is automatically determined whether the target values are reached (which are determined by the source and target profiles) and a correction is made for deviations. Iteration is therefore particularly useful in proofing situations with absolute or relative colorimetric rendering intents. Perceptive rendering intents can also be used as a special feature of DeviceLink iteration in CoPrA. The iteration calculates a new DeviceLink profile based on the original DeviceLink profile and the measured values. The new profile can be reinserted for iteration until the desired result is achieved.

Iteration for Proofing and Production Printing

Iteration is a great method to get the best possible match for proofing. Proofing uses absolute colorimetric rendering without color exceptions. However, in digital production printing, perceptual rendering methods and color exceptions are used to keep colors pure. Nevertheless, there might be an interest to optimize the colors by iteration measurements (Note: It is not always recommended to do so, especially as out-of-gamut colors cannot be optimized).

Using the Iterate tool, it is possible to iterate data for production printing while retaining exceptions during the iteration process. CoPrA recognizes exceptions and rendering settings from the selected reference DeviceLink profile and retains them (only if the selected DeviceLink is a ColorLogic profile). A checkbox is shown when exceptions are used. By default, the checkbox is enabled. 

Notes

  • Iterate requires a DeviceLink license.
  • The test chart must match the color space of the source profile. 
  • Out-of-gamut colors of the original color space can only be improved to a limited extent. 
  • In proofing situations, the gamut of the target color space ought to be larger than that of the source color space, which makes iteration particularly interesting for DeviceLink profiles in proofing applications.
  • Iterations cannot be repeated arbitrarily due to fluctuations in print output, print material and the reproducibility of measuring instruments. More than 2-3 iterations are usually not necessary and not recommended.
  • Only DeviceLink profiles whose source and target profiles are available and referenced in the DeviceLink profile can be iterated. A warning is issued if the required source and target profiles are missing.
  • Third-party DeviceLinks that reference the used source and target profiles can also be iterated.
  • DeviceLinks that use color Exceptions and perceptual rendering options (such as conversion and separation profiles) can be iterated as well, but it should be done with care and it can only be done for ColorLogic DeviceLink profiles.
    Iteration allows the target values to be reached more accurately, which can result in a loss of channel purity if no exception settings are retained. Perceptive rendering intents require an interpretation of the measurement data, which can lead to slight shifts during iteration.
  • With a DeviceLink and a Multicolor license Multicolor DeviceLinks can be iterated, too.

Procedure

Procedure

Procedure

  1. Select Iterate in the sidebar or DeviceLink Iteration in the Navigation menu.
  2. Select the DeviceLink profile that you would like to iterate from the drop-down menu. Make sure that both the source and target profiles used in the DeviceLink are available in the ICC profile folder of your operating system, as CoPrA needs those to calculate the iterated profile. 
  3. Convert the test chart to be used for iteration with the DeviceLink profile and print it on the printer using the same settings as for the profiling test chart for this printer. The test chart can be converted using CoPrA’s Image Conversion tool.
    
Note: Use a test chart that contains the colors you would like to optimize. Typically, test charts with few color patches will suffice, but those patches must reflect the colors to be optimized. Therefore, using large profiling test charts is not required. Instead of using large test charts, use charts that can also be used to update profiles (see ColorAnt/Custom Chart tool). The color space of the test chart must correspond to the color space of the source profile of the DeviceLink.
  4. Measure the printed test chart in ColorAnt, save the measurement data and open it in CoPrA’s Iterate tool, either via drag-and-drop or via the Load button. Alternatively, click Measure and measure the test chart with CoPrA’s integrated Measure Tool.
  5. Depending on the selected DeviceLink profile and its settings, the checkbox Use same Settings from DeviceLink including exceptions will be activated or grayed out. It is activated for ColorLogic DeviceLink profiles that use Exceptions. If the DeviceLink is not a CoPrA profile or if it does not use exceptions, – which should be the default setting for proofing, – the checkbox is grayed out.
    Note: If the checkbox Use same Settings from DeviceLink including exceptions is deactivated, then all Exceptions are deactivated in the iterated DeviceLink profile.
  6. If you disable the checkbox Use same Settings from DeviceLink including exceptions,  then all exceptions are disabled in the iterated DeviceLink profile.
  7. Click Next to get to the Save dialog Format, Size and Further processing.
    Notes:
    a) The Default Template uses an option to add the iteration count number to each iterated DeviceLink.
    b) Size: It is recommended to select Auto because size matters for iteration. The Auto feature ensures that the highest precision is always used when creating the iterated DeviceLink.
    c) The newly created DeviceLink will have a more accurate color rendering for most in-gamut colors compared to the original DeviceLink profile. You can now use it in exactly the same way as the original one or use it for further iterations..
  8. If you would like to further optimize the DeviceLink, proceed as described above. However, select the previously iterated DeviceLink instead of the original one. Now convert the original test chart with the iterated DeviceLink (do not take the already converted test chart from point 3!) and use the measurement data of this printout to calculate a further optimized DeviceLink profile.

Format, Size and Further Processing

In the last step of profile creation, assign a Name and choose the Format and Size of the profile (see screenshot).

Name: Type in a Name for the profile.

Templates: Allows to select and combine name components from a list of options and save them as custom templates. The last selected template is used when creating new profiles, so the naming of profiles is automated.
Available naming options depend on the current profile type and include Date, Date/Time, Measurement data file name, Source and Target profiles, Name of the current preset and others. Each name component can be added at a user-defined position under Template (the position is selected with the mouse pointer). The Example section below shows the resulting name. Additionally, user defined text can be added at any position within the Template field.

Format: Define the Format of your profile. An ICC format in accordance with specification v2 is recommended as basic setting however, the newer format ICC v4 can also be chosen. In this case, please ensure that your programs support this format.
Note: ColorLogic products handle and use ICC v4 profiles consistently and correctly.

Size: The setting Large is recommended. The size specifies the number of grid points in the profile and determines the amount of disk space required for the generated profile. Small profiles should only be used for test purposes. Very Large profiles can slow down further processing in subsequent programs. Additionally, some programs are not able to handle very large profiles.

Further processing

Create Profile Report (PDF): Recommended to activate. The PDF report provides an overview of the quality of the profile based on statistics, diagrams of gray balances, gradients and gamut representations as well as color separations of converted test files.

Save Preview Profile: Is only available in Multicolor printer profiling. By activating this checkbox an ICC preview profile will be created in addition to the printer profile. It can be used as a soft proof profile in Adobe Photoshop.
Notes: Preview profiles are only suitable for proofing purposes. Either a preview profile or a CMYK profile can be created in one profiling step, but not both.

Embed profiles: Physically incorporates the used source and target profiles into the DeviceLink. This function is tricky and only recommended if the DeviceLink has to be transferred to a computer which does not have the required source and target profiles. It was implemented mainly for use with certain RIPs which only accept DeviceLinks with embedded source and target profiles.

Save: Creates the printer profile and saves it in the folder Profiles (macOS) or Color (Windows), (macOS: /Users/Username/Library/ColorSync/Profiles, Windows: C:\\Windows\\System32\\spool\\drivers\\color). Demo and encrypted profiles will be saved in a different location only relevant for ColorLogic applications.

Note: CoPrA-SP profiles are stored in the ColorLogic subfolder Licensed-Profiles.

Verifying the optimization

Verifying the optimization

ColorAnt can be used to verify a successful optimization. First create a “Lab Reference” to compare the measured values of the printouts to the values of the DeviceLinks. Use the ICC Transformation tool to create the Lab reference values by using the device values of the original test chart and the source profile and rendering intent of the DeviceLink. These Lab reference values now serve as comparison values after each application of the iterated DeviceLinks on your test chart. Compare the measurements of the iteration with the “Lab Reference” using the Compare tool in ColorAnt. 

You will notice that in-gamut colors of the iterated DeviceLink are closer to the Lab reference than those of the original DeviceLink.

Video Tutorial: How to create a test chart for iteration

Video Tutorial: How to iterate