Compare

Working with 'Compare'

The following quality assessments are possible with "Compare":

•Comparison of the color data of two test charts, control elements or ICC profiles (quality check)

•Calculation and display of quality parameters and diagrams

•Printout of quality reports

To compare two color data sets, open the reference and comparison data using the relevant buttons, menu commands or the Explorer panel. You can open the color data of one test chart or test strip as the reference data and the data set of another test chart or test strip as the comparison data. You can use different types of data. In this case, the data in common will be used. For example, the "ISO 12642-2 / ECI 2002" test chart contains the "PCS 40" test strip and the "ISO 12642 / ANSI IT8.7/3" test chart or the "ISO 12642-2 / ANSI IT8.7/4" test chart contains all of the "ISO 12642-2 / ECI 2002" test chart. This is also applicable for the "Visual" and "Random" versions of the large test charts. In "FMS" test strips where identical patches occur several times, a comparison is made from the middle and the position evaluated.

You can view and compare all the device profiles based on the ICC specification and color data sets in the "ISO 12642" format, including those that were not created with Color Toolbox or with PrintOpen versions.

In "Preferences > Compare" you can enable "Use reference file for comparison" and set the path for a file that will be used as the reference during the comparison. After a restart of the application, this file is then always loaded automatically as the reference file in "Compare". This file is used as the comparison file when you open a file or create a new one in "Measure" and then go directly to "Com­pare". The comparison data from "Measure" are not used if you first go to another main function. You then have to open the comparison data you want manually.

You can usually use the following reference files:

•"HDMcoated_bb.txt": Measurements with black backing (BB); offset printing

Path: "<Drive>:\Prinect Color Toolbox\Color Tool xx.0\data\hdm"

•"FOGRA39L.txt": Measurements with white backing (WB); glossy or matte

Path: "<Drive>:\Prinect Color Toolbox\Color Tool xx.0\data\fogra"

•"FOGRAMK3ABC_FOGRA39.txt": Measurements with white backing (proof)

Path: "<Drive>:\Prinect Color Toolbox\Color Tool xx.0\data\fogra\MediaControl"

You can also use loaded data from "Analysis". To do this, in one of the diagrams you must click the point that represents the reference file you want and then click "Ref" in the context-sensitive menu (generally right-click). After that, select another point for the comparison file and click "Cmp" in the context-sensitive menu. The two files open in "Compare" as reference and comparison data as you defined them and appear in the test chart diagram.

Note: You can also open the files by dragging-and-dropping them to the status panel. A sim­ple drag-and-drop opens the file as a reference file, if you also hold down the Ctrl key the file opens as a comparison file.

Note: If you open color data sets in "Compare" whose reference and comparison file were measured with different measurement conditions, a warning displays in the footer, telling you that the measurement conditions do not match.

Note: The color distance values shown by default depend on what is saved in the selected process standard. You can toggle between ΔE_ab and ΔE₀₀ in each view. If you explicitly tog­gled the display between ΔE_ab and ΔE₀₀ once manually, the mode of the selected ΔE for­mula is kept until the Color Toolbox is exited.

You can also view the reference or comparison file separately by selecting or deselecting it in some diagrams.

You can open the following views and statistical results for the loaded color data sets using the tabs:

•"Test chart": You can view a composite display of the loaded test charts, control strips or linear­ization strips with small and large color patches (see 'Test chart' View):

·Absolute or differential values (display with miscolors)

·Display of statistical results for deviation

·Display of patches, optionally with ΔE values

•"xy diagram": This two-dimensional color space is shown as a horseshoe-shaped diagram, known as the chromaticity diagram. See 'xy diagram' View.

•"ab diagram": You can view a two-dimensional color display of the ab plane with or without the dots. See 'ab diagram' View.

•"La/Lb diagram": You can view a two-dimensional color display of the L*a*b* color space (par­allel to the lightness axis). See 'La/Lb diagram' View.

•"3D color space" (tab): You can view a three-dimensional display of the color space where the measured color data are displayed in an a*b* diagram (CIE L*a*b* or CIELAB color space). See '3D color space' View.

•"3D color space" (button bar): You can view a separate three-dimensional display of the color space where the measured color data are displayed in an a*b* diagram (CIE L*a*b* or CIELAB color space). See 3D display of the color space (with central projection and/or animation).

•"Statistics": You can view different diagrams with statistical results that refer to the CIELab color values. See 'Statistics' View:

·Error histogram

·Trend (error distribution)

·Trend with mean (error distribution)

•"CIE report": You can compare the color data of two test charts, control elements or ICC profiles (quality check) with the following weighting (see 'CIE report' View):

·Dot gain at 25%, 40%, 50%, 70%, 75% and/or 80%

·Solid tint density values

·CIELab color values

·Analysis

·Proof report

•"Proof report": Displays the overall result of a ΔE proof evaluation with the key color data (quick overview). You can set that other evaluation parameters will be shown in the "Preferences > Proof Report" dialog (see 'Proof statistics' View).

•"Proof statistics": Display of the statistical results in the following diagrams (see 'Proof statistics' View):

·an error histogram

·two Lab scatter diagrams

•"ΔLab report": Display of four histograms for a frequency distribution of differential color values (Lab color values). See 'ΔLab report' View.

•"ΔLCH report": Display of four histograms for a frequency distribution of differential color values (LCH values). See 'ΔLCH report' View.

•"Tonal values": Display of different diagrams, see 'Tonal values' View:

·Dot gain (curves)

·Printing Characteristic

·Density curves (density profile)

·CTV

•"Data table": Display of all the measured and calculated values in a table. You can select which values will be shown in the table by checking the appropriate boxes to the right of the table or in the "Preferences" dialog (see 'Data table' View).