Range of L*a* b* in Matlab

Question

I'm trying to use the Lab color-space for contrast enhancement through histogram equalization but I don't know the range of values for L, a and b, and I can't find it online for Matlab.

Any help?

Answer 1

There are some small difference in the min/max a b values between CIE, ICC and Tiff encoding specifications but typically: L* should be 0-100. a b are usually bounded to +/- 127.

With real world color data you will likely find that few color approach the max values for a/b. If your input data sets are derived from RGB encoded colors you can further optimize the Lab value range to conform to the max value in a given RGB color space. The page below has some great background information on the subject.

http://www.brucelindbloom.com/

Answer 2

They are in range of L(0,100) , a(-86,98), b(-107,94) . You can find the ranges by using their corresponding equations .