A color validation test has a series of metrics that are calculated and evaluated when the test is performed.
The tables lists all metrics that can be used in a color validation test. In practice, a color validation test uses a small subset of the available metrics.
The measurements are the measured Lab values of the patches of the printed target chart of the test.
|
Metrics |
Description |
|---|---|
|
Substrate ΔE00 |
Color difference in ΔE00 between the measured and the reference substrate white. For a side-by-side evaluation, the color control strip must be printed with the rendering intent absolute colorimetric. The reference substrate white is compared to the measured simulated substrate white of the printed media. |
|
Maximum ΔE00 |
Highest color difference in ΔE00 between the measured Lab values of the color patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Average ΔE00 |
Average color difference in ΔE00 between the measured Lab values of the color patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
95th percentile ΔE00 |
The 95th percentile ΔE00 color difference between the measured Lab values of the color patches on the color control strip and the Lab values of the matching patches of the reference printing condition. This means that 95% of all measured patches have ΔE00 color differences smaller than or equal to the metric value. |
|
Maximum ΔE00 CMYK solids |
Highest color difference in ΔE00 between the measured Lab values of the CMYK solid patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum ΔE00 CMY solids |
Highest color difference in ΔE00 between the measured Lab values of the CMY solid patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum ΔE00 RGB overprints |
Highest color difference in ΔE00 between the measured Lab values of the RGB overprint patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
NOTE
Delta E 2000, △E00 is the industry standard.
|
Metrics |
Description |
|---|---|
|
Substrate ΔE76 |
Color difference in ΔE76 between the measured and the reference substrate white. For a side-by-side evaluation, the color control strip must be printed with the rendering intent absolute colorimetric. The reference substrate white is compared to the measured simulated substrate white of the printed media. |
|
Maximum ΔE76 |
Highest color difference in ΔE76 between the measured Lab values of the color patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Average ΔE76 |
Average color difference in ΔE76 between the measured Lab values of the color patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
95th percentile ΔE76 |
The 95th percentile ΔE76 color difference between the measured Lab values of the color patches on the color control strip and the Lab values of the matching patches of the reference printing condition. This means that 95% of all measured patches have ΔE76 color differences smaller than or equal to the metric value. |
|
Maximum ΔE76 CMYK solids |
Highest color difference in ΔE76 between the measured Lab values of the CMYK solid patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum ΔE76 CMY solids |
Highest color difference in ΔE76 between the measured Lab values of the CMY solid patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum ΔE76 RGB overprints |
Highest color difference in ΔE76 between the measured Lab values of the RGB overprint patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
NOTE
Delta E 1976, △E76 is based on a less complicated and accurate distance calculation.
|
Metrics |
Description |
|---|---|
|
Maximum ΔH CMYK solids |
Highest color difference in ΔH between the measured Lab values of the CMYK solid patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum ΔH CMYK solids and RGB overprints |
Highest color difference in ΔH between the measured Lab values of the CMYK solid patches and the RGB overprint patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum ΔH CMY solids and RGB overprints |
Highest color difference in ΔH between the measured Lab values of the CMY solid patches and the RGB overprint patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum ΔH CMY solids |
Highest color difference in ΔH between the measured Lab values of the CMY solid patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Average ΔH composite grays |
Average color difference in ΔH between the measured Lab values of the composite gray patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum ΔH composite grays |
Highest color difference in ΔH between the measured Lab values of the composite gray patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Metrics |
Description |
|---|---|
|
Average |ΔL| composite grays |
Average lightness difference in |ΔL| between measured Lab values of the composite gray patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum |ΔL| composite grays |
Highest lightness difference in |ΔL| between measured Lab values of the composite gray patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Average weighted |ΔL| composite grays |
Average lightness difference in weighted |ΔL| between measured Lab values of the composite gray patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum weighted |ΔL| composite grays |
Highest lightness difference in weighted |ΔL| between measured Lab values of the composite gray patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Average |ΔL| K-only patches |
Average lightness difference in |ΔL| between measured Lab values of the K-only patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum |ΔL| K-only patches |
Highest lightness difference in |ΔL| between measured Lab values of the K-only patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Average weighted |ΔL| K-only patches |
Average lightness difference in weighted |ΔL| between measured Lab values of the K-only patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum weighted |ΔL| K-only patches |
Highest lightness difference in weighted |ΔL| between measured Lab values of the K-only patches on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Estimated black point |ΔL| |
Lightness difference in |ΔL| between the measured darkest patch on the color control strip and the darkest patch of the reference printing condition. The darkest patch is the patch that has the lowest L* value. |
NOTE
The |ΔL| value refers to the absolute value of △L.
The weighted |ΔL| puts more emphasis on the color differences for light grays, where the K value is lower than 50%.
The Estimated black point |ΔL| metric is called an estimation because the darkest patch of the target chart is not necessarily the darkest possible color. There could be CMYK values that reproduce a darker tint. The output profile determines the real black point value.
|
Metrics |
Description |
|---|---|
|
Average ΔCh composite grays |
Average color difference in ΔCh between measured Lab values of the composite grays on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum ΔCh composite grays |
Highest color difference in ΔCh between measured Lab values of the composite grays on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Average weighted ΔCh composite grays |
Average color difference in weighted ΔCh between measured Lab values of the composite grays on the color control strip and the Lab values of the matching patches of the reference printing condition. |
|
Maximum weighted ΔCh composite grays |
Highest color difference in weighted ΔCh between measured Lab values of the composite grays on the color control strip and the Lab values of the matching patches of the reference printing condition. |
NOTE
The weighted ΔCh puts more emphasis on the color differences between composite grays, where C is lower than 50%.