+1(978)310-4246 credencewriters@gmail.com

Lab 5.1Â CIELAB Color Difference

Â

Purpose: Learn how to calculate CIELAB color differenceÂ Using CIE L*a*b*C*H* Coordinates

Procedure:

Defined by the Commission Internationale de lâ€™Eclairage (CIE), the L*a*b* color space was modeled after a color-opponent theory stating that two colors cannot be red and green at the same time or yellow and blue at the same time. As shown below, L* indicates lightness, a* is the red/green coordinate, and b* is the yellow/blue coordinate. Deltas for L* (Î”L*), a* (Î”a*) and b* (Î”b*) may be positive (+) or negative ( -). The total difference, Delta E (Î”E*), however, is always positive.

Î”L* (L* sample minus L* standard) = difference in lightness and darkness (+ = lighter, â€“ = darker)
Î”a* (a* sample minus a* standard) = difference in red and green (+ = redder, â€“ = greener)
Î”b* (b* sample minus b* standard) = difference in yellow and blue (+ = yellower, â€“ = bluer)

Î”C* (C* sample minus C* standard) = difference in chromaÂ Â (+ = Higher chroma, â€“ = lower chroma)

There are four colors in the table below, one Standard and three batches.Â

 Colors L* a* b* Lab Standard 71.2 12.8 32.8 Lab Sample 1 71.1 18.7 31.8 Lab Sample2 72.5 13.8 31.0 Lab Sample 3 68.5 13.3 15.5

Now calculate CIELAB color differences for these colors and include all highlighted lines (steps) if possible:

Lab Sample 1 vs. Standard A

Lab Sample2 vs. Standard A

Lab Sample3 vs. Standard A

Â

Which batch has less color difference compare to Standard A?

Â Fill in the below table with all data.Â

 Colors L* a* b* âˆ†L* âˆ†a* âˆ†b* âˆ†C* âˆ†H* âˆ†E* The description of the difference in L*, a*, and b* Lab Standard 71.2 12.8 32.8 Â Lab Sample 1 71.1 18.7 31.8 Â Â Â Â Â Â Â Lab Sample 2 72.5 13.8 31 Â Â Â Â Â Â Â Lab Sample 3 68.5 13.3 15.5 Â Â Â Â Â Â Â

Â Examples of calculation:

Â

LAB 5.2: Compare your results of CIELAB and Calculate CMC and CIE2000 DE:

Step 1: visit the website:

Step 2: Fill the table in below:

 Colors L* a* b* CIELAB (1976) DE CMC (2:1) DE CIE2000 (1:1:1) DE Lab Reference 71.2 12.8 32.8 Â Lab Sample 1 71.1 18.7 31.8 Â Â Â Lab Sample 2 72.5 13.8 31.0 Â Â Â Lab Sample 3 68.5 13.3 15.5 Â Â
error: Content is protected !!