Compare DeltaE between two measurements
I want to compare DeltaE's between two measurement files, to see what differences there are between the two measurements. How can I do this with ColorThink Pro?
This is one of the easier tasks you can perform using the ColorThink Pro worksheet. In addition, you can view the resulting delta E differences as they show up on the page, or by grouping the worst offenders together.
How to do it
- Click and drag your 1st measurement set into ColorThink Pro to automatically open up a new worksheet.
- Click and drag your 2nd measurement set into the worksheet. This automatically opens up a second workflow.
- Click the Delta E button under the workflow tab.
- Click the Image tab to show the image.
The third "image" which shows up on the right gives a general representation of where the various delta E differences fall out on the measured sheet itself. By default, values less than 1 are displayed as green, values between 1 and 3 are yellow, values between 3 and 8 are brown, and those greater than 8 show up as red. These delineations can be changed using the sliders in the Delta E window.
What does this tell me?
- Normally you would expect to see small delta E amounts and they would be evenly spread.
- If you have a grouping of large delta E numbers on one section of your sheet, then your press may be printing poorly on that side.
- If one line of the measurement page is noticeably worse than others, a hand-held eye-one used to read it may have been poorly aligned or not seated correctly in the 'ruler'.
Another useful method of viewing delta E is to group the colorlist according to delta E deviation.
- Click on the Delta E column header at the top of delta E column in the color list. (This will align all the colors according to delta E variation from least to greatest.)
- Click the column header again to order all the colors the opposite way (from greatest to least.)
Now the colors are arranged so that the worst delta E offenders are at the top. In the example above we see a disproportionate representation of light colors and strong magentas.
View Delta E deviation in 3D graph
- Highlight several rows of colors using Shift+Click,
- Click one of the three column titles. (The delta E column will be titled "<untitled list>".)
- Choose "Graph List"
The colorlist will be opened in a 3D graph, and the highlighted colors will be marked with large white cross hairs. This will show where the largest delta E variations lie within the device gamut.
Change Delta E calculations
ColorThink Pro also gives you the option to use different delta E calculation algorithms. Click on the dE2000 drop-down tab to view several popular formulas.