CHROMiX

Evaluating a profile - Where is measurement data?

When Evaluating a profile with the ColorSmarts guide, we have the Profile, and the reference data, but how do we obtain the Measurement data? We used Gretag MacBeth’s Eye-One Match to create the profile from HutchColor’s HCT Precision Scanner Target, and have the Reference data supplied with the HCT CD, but we need to know how to obtain the Measurement data. Thanks in advance!

herzog, are you talking about a scanner profile? Then, in the case of a scanner profile, measurement data is the RGB numbers you got from your scanner target. When it comes to printer profile, you can get the measurement data in Lab if you open the profile in X-Rite’s MeasureTool, or you can get all those spectral data if you open the profile in Apple’s ColorSync Utility.

Thanks so much for your reply. It is a scanner profile. I still don’t understand: where do you get the RGB numbers from the scanner target? Is it a file somewhere? What format?

The RGB values are coming from your scan of the Hutch target…for example, you scan the Hutch target as a Tiff, the RGB values are from that Tiff.

If you want to evaluate the scanner profile, try creating a color list and comparing that to the reference file. For example, open a new worksheet in Color Think and drop your Tiff image on the worksheet. You can then create a color list of the RGB values by selecting the “target marquee” icon (says “Select target values to create a list” when hovering over with mouse) and selecting the target type (HutchColor HCT in this case). Once you get the RGB values, you can assign your scanner profile to it to derive Lab values. Drop on your HCT reference file and click the delta E button to show the dalta values between your “measurement” data and the reference file. Click the rpt (report) button for a summary.