lab2xyz

lab2xyz

skimage.color.lab2xyz(lab, illuminant='D65', observer='2') [source]

CIE-LAB to XYZcolor space conversion.

Parameters:	lab : array_like The image in lab format, in a 3-D array of shape (.., .., 3). illuminant : {“A”, “D50”, “D55”, “D65”, “D75”, “E”}, optional The name of the illuminant (the function is NOT case sensitive). observer : {“2”, “10”}, optional The aperture angle of the observer.
Returns:	out : ndarray The image in XYZ format, in a 3-D array of shape (.., .., 3).
Raises:	ValueError If lab is not a 3-D array of shape (.., .., 3). ValueError If either the illuminant or the observer angle are not supported or unknown. UserWarning If any of the pixels are invalid (Z < 0).

Notes

By default Observer= 2A, Illuminant= D65. CIE XYZ tristimulus values x_ref = 95.047, y_ref = 100., z_ref = 108.883. See function ‘get_xyz_coords’ for a list of supported illuminants.

References

[R44]

http://www.easyrgb.com/index.php?X=MATH&H=07#text7

[R45]

http://en.wikipedia.org/wiki/Lab_color_space