why use 0.008856 in Lab color space?
3 views (last 30 days)
Show older comments
In Lab color space equations, why use 0.008856 as thresholds if we transform RGB to Lab? Lab color space equation are the following:
•The conversion formula of RGB image into Lab image is:
X = 0.4124*R + 0.3576*G + 0.1805*B
Y = 0.2126*R + 0.7152*G + 0.8220*B
Z = 0.0193*R + 0.1192*G + 0.9505*B
If X/X_n,Y/Y_n,Z/Z_nare all greater than 0.008856,then
L* = 116∛("Y/" Y_n )- 16
a* = 500 ( ∛("X/" X_n )- ∛("Y/" Y_n ))
b* = 200 (∛("Y/" Y_n )- ∛("Z/" Z_n ))
If X/X_n,Y/Y_n,Z/Z_nare all equal to or less than 0.008856,then
L* = 903.3(Y/Y_n,)
a* = 500 (f(X/X_n,) – f(Y/Y_n))
b* = 200 (f(Y/Y_n) – f(Z/Z_n))
Why let these thresholds 0.008856?
If less than 0.008856, what we get?
And, if greater than 0.008856, what we get?
Please!!!
0 Comments
Answers (0)
See Also
Categories
Find more on Image Processing Toolbox in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!