de2000中有错误

[vip594nb]

def delta_e_cie2000(lab_color_vector, lab_color_matrix, Kl=1, Kc=1, Kh=1):
R_C = numpy.sqrt((numpy.power(avg_C1p_C2p, 7.0)) / (numpy.power(avg_C1p_C2p, 7.0) + numpy.power(25.0, 7.0)))
应该为
R_C = 2*(numpy.sqrt((numpy.power(avg_C1p_C2p, 7.0)) / (numpy.power(avg_C1p_C2p, 7.0) + numpy.power(25.0, 7.0))))
少乘以2了

[KelSolaar]

Hi @vip594nb,

Would it be possible to update/re-post in english please?

Cheers,

Thomas

[JensBloemer]

It says

def delta_e_cie2000(lab_color_vector, lab_color_matrix, Kl=1, Kc=1, Kh=1):
R_C = numpy.sqrt((numpy.power(avg_C1p_C2p, 7.0)) / (numpy.power(avg_C1p_C2p, 7.0) + numpy.power(25.0, 7.0)))
should be
R_C = 2*(numpy.sqrt((numpy.power(avg_C1p_C2p, 7.0)) / (numpy.power(avg_C1p_C2p, 7.0) + numpy.power(25.0, 7.0))))
(multiply by 2)

[s51517765]

I don't think this is a mistake.
The 2 in this case is contained in R_T.
R_T = -2 * R_C * numpy.sin(2 * numpy.radians(delta_ro))

So,
R_C = numpy.sqrt((numpy.power(avg_C1p_C2p, 7.0)) / (numpy.power(avg_C1p_C2p, 7.0) + numpy.power(25.0, 7.0)))
is OK.

[s51517765]

@vip594nb @KelSolaar
I have checked.
It all matches (4 decimal places) with TABLE 1. of the following paper, and I think it is correct.
http://www2.ece.rochester.edu/~gsharma/ciede2000/ciede2000noteCRNA.pdf