EasyMatch QC – Example Display of L*/b* ratio as a Custom Formula Follow

FAQ: “Can you describe how to enter a Custom Formula Field in EasyMatch QC?”

The Custom Formula Field allows you to create your own measurement metric based on one of the standard metric without software customization or needing to know a programming language. It is very similar to entering a formula in Excel.

As an example, here is how to set up a Custom Formula Field for L*/b* ratio which is not a standard metric in EasyMatch QC.

Put your mouse over the Color Data Table/Right Click/Configure.

Let’s assume we are going to make the L*/b* ratio based on the CIE L*, a*, b* color scale.

In Scales, select for display “CIELAB (A, B, C)” for D65/10 illuminant/observer conditions that will display in the Color Data Table as columns A, B, C.

As an example to work with, read a white tile as a Standard.

Select “Insert Custom Field” and then “Formula Field” (not Data Field).

Then enter a Name or Label for this custom metric (use only letters and numbers) and select “OK” to go to the next screen to enter the customer formula.

In this case L* is in Column A; b* is in column C, so we would enter the formula after the “=” sign as follows.

L to B Ratio = A#/C# where “#” means all rows.

*See you User’s Reference Manual for more details about entering Custom Formulas and the different types of built-in functions you can use.

Select “Set Formula” and you will see the L*/b* Ratio display in Column D. Check the math manually to make sure that the entered custom formula is calculating correctly. Select “OK” to close and return to the Configure Data Table Configuration screen.

Under Text Fields, there will now be a selection called “Formula Fields” that you just created and which can be selected and pushed to the left into “Selected Items” as Column D for display.

Select “OK” to return to the main screen where you will see your Custom Formula displayed in the Color Data View.

*Note: The columns are not dynamic with this Custom Formula Tool. If you add another color scale to the Color Data View such that L* and b* are no longer in Columns A and C, then you will have to revise your custom formula.

As a final step, go to “File/Save Template As” and re-save this custom formula as your Default Template (typically saved as “01 Basic Color Template” at c:\hunterlab\easymatch qc\job templates sub-folder).