ColorAnt | CIE Conversions

CIE Conversion

Change the standard observer and illumination of data sets

CIE Conversion

The CIE Conversion tool converts measurement data into another viewing condition.

Possible tasks can include the presentation of photos in a gallery under incandescent light (corresponds approximately to illuminant A) or displays under exhibition lighting, where the lighting consists of fluorescent light. Another task is to change the illumination and observer angle for the textile industry, where D65 and a 10-degree observer are used as standard.

The Illumination drop-down menu contains the following options:

  • Selection of a standard illuminant: D50, D65, illuminant A or the Equal Energy Spectrum. Typically, printer profiles are created for D50 viewing conditions.
  • Manual input of Kelvin or XYZ values.
  • Emission (Open File): Selection of spectral emissions readings (as CxF3 or text file) of a specific light source. The data can be loaded or dragged and dropped onto the selection. ColorAnt can also extract data (the white point) from a measurement file and display these values.
  • Emission (Measure): Opens the Measure Tool in Ambient Light Measurement mode. The ambient light can be measured directly from within the CIE Conversion tool using supported devices (e.g. X-Rite i1Pro and Konica-Minolta FD-7). For more information, see the Measure Tool help.

Observer: Can be changed from 2 degrees to 10 degrees.

Resulting file: Spectral data are converted to Lab during CIE conversion with the set illumination and the selected observer. The resulting measurement file contains only Lab values. You can then use this file to create profiles.
Note: Use the CIE Conversion as the last step due to the conversion of spectral data to Lab.

Important: The CIE Conversion can only be used with spectral measurement data from test charts, otherwise the tool is grayed out.

Procedure

  1. Select a spectral measurement file of a test chart and open the CIE conversion.
  2. Under Illumination, select one of the predefined illuminants, or manually enter the measured illuminant as Kelvin value or XYZ value. You can also simply drag a measurement file (TXT and CxF3 file) of the measured light onto the value field. Alternatively, to select a spectral light measurement, select Emission (Open File) from the drop-down menu and select your measurement file in the subsequent dialog.

    Note: If you choose to enter your own illumination, it is recommended to work with one of the two emission options, since spectral data is used throughout.
    Multiple measurements of the same light source: If there are multiple measurements in a measurement file, it is best to use the Redundancy tool for averaging, to save the file and then use it as an Emission (Open File) in the CIE Conversion.
  3. Under Observer, select the desired observer angle, 2 or 10 degrees.
  4. Click Start and the spectral data are converted into Lab.

ColorAnt | Averaging

Averaging

Average several data sets into one data set

Averaging Data Sets in ColorAnt

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 | ICC Transformation

ICC Transformation

Use ICC device and DeviceLink profiles to test impact on data.

Using ICC Transformation

The ICC Transformation tool applies ICC device profiles and DeviceLinks to reference data (device values such as CMYK) to synthetically check the effect of ICC color conversion with up to three profiles.

Note: You have the option to select an ICC profile from the drop-down menu, or use a profile that is not in the ICC profile folder of your operating system. For example, if you would like to use a profile located on the desktop of your computer, you can simply drag and drop it onto the drop-down menu. If it matches the selected data, it will immediately appear in the drop-down menu.

Only ICC profiles that match the loaded data are displayed in the drop-down menus. For example, only CMYK profiles or CMYK DeviceLinks are displayed if CMYK measurement or reference data have been loaded. This prevents unnecessary error messages due to inappropriate profile selection.

The checkboxes in front of the drop-down menus for profile selection determine which conversions are carried out. When an ICC profile is selected, the device values of the reference file are converted to Lab using the selected rendering intent. If a DeviceLink profile is selected, the device values are converted to the device values of the target color space of the DeviceLink.

This example demonstrates how a SaveInk-DeviceLink profile works.

Procedure

  1. Open the same large test chart layout (e.g. IT8.7-4) twice via File/Open Predefined. The CMYK reference values of this test chart are opened.
  2. Select the first opened reference file. Apply the original printer profile which created the Savelnk profile, and is available in the reference file in the ICC Transformation drop-down menu. Convert the reference file to Lab with the Absolute Colorimetric rendering intent.
  3. Now select the second reference file. First apply the SaveInk-DeviceLink profile and secondly the original printer profile using the Absolute Colorimetric rendering intent. In addition to converting the reference file to Lab, the CMYK values are also changed using the SaveInk profile.
  4. The objective of a SaveInk conversion is to visually keep the consistency of the original printer profile, despite modified (reduced) CMYK values to achieve the lowest possible color deviations. Compare both files in the Color Comparison window. The Graph tab displays the average deviation (Average) is 0.1 Delta E and the maximum deviation (Maximum) is 1.2 DeltaE in this example. 90% of the deviations (90% percentile) do not diverge by more than 0.2 DeltaE.

ColorAnt | Link

Link

Combine sets of measurement data

Link multiple data sets

Three options are available in the Link tool. The options are grouped with radio buttons that are enabled and disabled according to the chosen files.

Link data with same color space: combine several separate measurement data files with the same color space to one large data set. For example, combine three CMYK data sets to one large CMYK measurement data set.

Combine CIE with DCS: combines two separate files to one data set. This option is enabled if one file contains the reference data (DCS – Device Color Space) and the other file contains the measurement data (CIE) and both have the same number of patches.

Merge by Channel Name: links multicolor measurement data from different sources, e.g. separate Esko Equinox measurement data files. Combines separate measurement data files with different channel names to a new file. For example if you combine a four color CMYK file with a CMYK+Orange data set the resulting file will be a 5 color data set CMYK+Orange with additional CMYK data.

Note: Combining multicolor data requires a ColorAnt L license.

Tip: ColorLogic suggests averaging the redundant color patches with the Redundancies tool after using the Link tool. Delete redundant color patches by activating the Remove Duplicate Patches checkbox next to the averaging method. The methods for averaging redundant color patches are the same as in the Averaging tool.

View the channel re-ordering options in Edit Primaries.

How to link multiple Multicolor data sets: