Hello,
You could use Excel and Gretag Macbeth’s Keywizard software for this task. Keywizard (PC only) lets you connect to an Eye One (or a SpectroEye, Spectrolino, …) and it will transfer the Lab values of a measured patch to the frontmost application, in this case Excel. Somewhere in the worksheet you enter the reference values, and let Excel calculate the delta E between the reference and sample value. This is the flow I use to determine the relation wet density vs dry Cielab and delta E to find out optimum wet density. In Excel you can even automatically graph the relation between wet density and delta E.
Another way is a combination of Eye One Share, Color Picker (from the Gretag Profilemaker software) and Measuretool.
First with Color Picker enter the Lab values of the reference. Maybe enter the lab values of C, M, Y, K and paper white. Name the samples and save the file as CXF format (dongle required)
Next, in Measuretool, measure all the samples using a custom color chart. If you want to measure 10 values for example, enter columns ‘1’ and rows ‘10’, and start measuring the 10 samples with an Eye One. Save the file as CXF.
Place the file with 10 measurements in the ‘standards’ subdirectory of Eye One Share. On Mac OS X, you must click on the application, and choose Show Package Contents. Start Eye One share, and load the file with the reference values. Eye One Share will display a message that it will create the spectral values from Lab: this is ok. Resave the file once it has been converted too. Click on the cyan reference color, and in the bottom row with the libraries, choose the library with your measurement data. The library will be sorted from lowest dE to highest. To know the dE, drag your reference value to the left half of the big circle, and the left most patch from the library to the right half of the circle, or vice versa. Beneath the circle, dE is show between reference and sample.
Of course, you could measure your samples within Eye One Share directly too.
In the pressroom, I too use a SpectroEye with the ISO 12647-2 values loaded as a job. Together with it’s Bestmatch function, it even suggests to lower or raise density in order to obtain lowest delta E depending on the measured patch. Great tool.
Hope this helps you further a bit.
Regards,
Yann Bouckaert