1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
|
import argparse, numpy as np, sys
import scipy.interpolate
import PIL.Image
import crl
parser = argparse.ArgumentParser()
parser.add_argument("colorspace", type=str, nargs=1)
parser.add_argument("output", type=str, nargs=1)
parser.add_argument("--resolution", type=int, default=500)
args = parser.parse_args()
try:
CS, polar_x0, polar_y0 = {
"xy": (crl.xyY, 0.25, 0.40),
"uv": (crl.uvY, 0.25, 0.20),
"uv76": (crl.uvY76, 0.25, 0.20),
"UVstar": (crl.UVstarNormed, 0, 0),
"Labstar": (crl.LabstarD65, 0, 0)
}[args.colorspace[0]]
except KeyError:
print("error: '%s' is not a supported color space" % args.colorspace[0])
parser.print_help()
exit(1)
def diagram_xy():
def polar(u, v):
du = u - polar_x0
dv = v - polar_y0
r = np.sqrt(du ** 2 + dv ** 2)
phi = np.arctan2(du, dv)
return r, phi
# First, the spectral color locus
locus = []
wvls = list(np.linspace(380, 780, 400))
for i, wvl in enumerate(wvls):
x, y, _ = CS(crl.PointSpectrum(wvl))
if i == 0:
x0, y0 = x, y
elif i == len(wvls) - 1:
x1, y1 = x, y
r, phi = polar(x, y)
locus.append([phi, r])
# Then, the line of purples (interpolate from x0,y0 to x1,y1)
for t in np.linspace(0, 1, 40):
s = 1 - t
x = s * x0 + t * x1
y = s * y0 + t * y1
r, phi = polar(x, y)
locus.append([phi, r])
locus = sorted(np.array(locus), key=lambda v: v[0])
locus = np.array(locus)
cull_func = scipy.interpolate.interp1d(
locus[:, 0], locus[:, 1], "linear", fill_value="extrapolate")
bounds = crl.plot_data[CS]["diagram_bounds"]
im = np.zeros([args.resolution, args.resolution, 4])
for i in range(im.shape[0]):
for j in range(im.shape[1]):
x = i / (im.shape[0] - 1) * (bounds[1] - bounds[0]) + bounds[0]
y = (1 - j / (im.shape[1] - 1)) * (bounds[3] - bounds[2]) + bounds[2]
r, phi = polar(x, y)
if r > cull_func(phi):
continue
im[j, i] = np.array([*crl.sRGB(CS(x, y, 1)), 1])
return im
def diagram_ab():
bounds = crl.plot_data[CS]["diagram_bounds"]
im = np.zeros([args.resolution, args.resolution, 4])
for i in range(im.shape[0]):
for j in range(im.shape[1]):
x = i / (im.shape[0] - 1) * (bounds[1] - bounds[0]) + bounds[0]
y = (1 - j / (im.shape[1] - 1)) * (bounds[3] - bounds[2]) + bounds[2]
im[j, i] = np.array([*crl.sRGB100(CS(75, x, y)), 1])
return im
if CS == crl.LabstarD65:
im = diagram_ab()
else:
im = diagram_xy()
np.clip(im, 0, 1, out=im)
image = PIL.Image.fromarray((im * 255).astype("uint8"))
image.save(args.output[0])
|
