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# -*- coding: utf-8 -*-
import math
from DisplayCAL import colormath
# from xcolorants.c
icx_ink_table = {
"C": [[0.12, 0.18, 0.48], [0.12, 0.18, 0.48]],
"M": [[0.38, 0.19, 0.20], [0.38, 0.19, 0.20]],
"Y": [[0.76, 0.81, 0.11], [0.76, 0.81, 0.11]],
"K": [[0.01, 0.01, 0.01], [0.04, 0.04, 0.04]],
"O": [[0.59, 0.41, 0.03], [0.59, 0.41, 0.05]],
"R": [[0.412414, 0.212642, 0.019325], [0.40, 0.21, 0.05]],
"G": [[0.357618, 0.715136, 0.119207], [0.11, 0.27, 0.21]],
"B": [[0.180511, 0.072193, 0.950770], [0.11, 0.27, 0.47]],
"W": [
[0.950543, 1.0, 1.089303], # D65 ?
colormath.get_standard_illuminant("D50"),
], # D50
"LC": [[0.76, 0.89, 1.08], [0.76, 0.89, 1.08]],
"LM": [[0.83, 0.74, 1.02], [0.83, 0.74, 1.02]],
"LY": [[0.88, 0.97, 0.72], [0.88, 0.97, 0.72]],
"LK": [[0.56, 0.60, 0.65], [0.56, 0.60, 0.65]],
"MC": [[0.61, 0.81, 1.07], [0.61, 0.81, 1.07]],
"MM": [[0.74, 0.53, 0.97], [0.74, 0.53, 0.97]],
"MY": [[0.82, 0.93, 0.40], [0.82, 0.93, 0.40]],
"MK": [[0.27, 0.29, 0.31], [0.27, 0.29, 0.31]],
"LLK": [
[0.76, 0.72, 0.65], # Very rough - should substiture real numbers
[0.76, 0.72, 0.65],
],
"": [[0.0, 0.0, 0.0], [0.0, 0.0, 0.0]],
}
s = {"Ynorm": 0.0, "iix": {0: "R", 1: "G", 2: "B"}}
for e in range(3):
s["Ynorm"] += icx_ink_table[s["iix"][e]][0][1]
s["Ynorm"] = 1.0 / s["Ynorm"]
def XYZ_denormalize_remove_glare(X, Y, Z):
XYZ = [X, Y, Z]
# De-Normalise Y from 1.0, & remove black glare
for j in range(3):
XYZ[j] = (XYZ[j] - icx_ink_table["K"][0][j]) / (1.0 - icx_ink_table["K"][0][j])
XYZ[j] /= s["Ynorm"]
return tuple(XYZ)
def XYZ_normalize_add_glare(X, Y, Z):
XYZ = [X, Y, Z]
# Normalise Y to 1.0, & add black glare
for j in range(3):
XYZ[j] *= s["Ynorm"]
XYZ[j] = XYZ[j] * (1.0 - icx_ink_table["K"][0][j]) + icx_ink_table["K"][0][j]
return tuple(XYZ)
def RGB2XYZ(R, G, B): # from xcolorants.c -> icxColorantLu_to_XYZ
d = (R, G, B)
# We assume a simple additive model with gamma
XYZ = [0.0, 0.0, 0.0]
for e in range(3):
v = d[e]
if v < 0.0:
v = 0.0
elif v > 1.0:
v = 1.0
if v <= 0.03928:
v /= 12.92
else:
v = math.pow((0.055 + v) / 1.055, 2.4) # Gamma
for j in range(3):
XYZ[j] += v * icx_ink_table[s["iix"][e]][0][j]
return XYZ_normalize_add_glare(*XYZ)
def XYZ2RGB(X, Y, Z):
return colormath.XYZ2RGB(*XYZ_denormalize_remove_glare(X, Y, Z))
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