commit 2b90f67cf42c15b9bf88c23bc9d93f558bdcdf59 · cduck.me/drawsvg

+199
color.py
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       import math

     

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       import numpy as np

     

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       import pwkit.colormaps  # pip3 install pwkit

     

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       # Most calculations from http://www.chilliant.com/rgb2hsv.html

     

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       def limit(v, low=0, high=1):

     

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           return max(min(v, high), low)

     

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       class Srgb:

     

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           LUMA_WEIGHTS = (0.299, 0.587, 0.114)

     

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           def __init__(self, r, g, b):

     

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               self.r = float(r)

     

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               self.g = float(g)

     

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               self.b = float(b)

     

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           def __iter__(self):

     

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               return iter((self.r, self.g, self.b))

     

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           def __repr__(self):

     

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               return 'RGB({}, {}, {})'.format(self.r, self.g, self.b)

     

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           def __str__(self):

     

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               return 'rgb({}%,{}%,{}%)'.format(self.r*100, self.g*100, self.b*100)

     

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           def luma(self, wts=None):

     

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               if wts is None: wts = self.LUMA_WEIGHTS

     

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               rw, gw, bw = wts

     

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               return rw*self.r + gw*self.g + bw*self.b

     

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           def toSrgb(self):

     

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               return self

     

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           @staticmethod

     

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           def fromHue(h):

     

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               h = h % 1

     

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               r = abs(h * 6 - 3) - 1

     

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               g = 2 - abs(h * 6 - 2)

     

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               b = 2 - abs(h * 6 - 4)

     

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               return Srgb(limit(r), limit(g), limit(b))

     

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       class Hsl:

     

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           def __init__(self, h, s, l):

     

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               self.h = float(h) % 1

     

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               self.s = float(s)

     

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               self.l = float(l)

     

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           def __iter__(self):

     

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               return iter((self.h, self.s, self.l))

     

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           def __repr__(self):

     

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               return 'HSL({}, {}, {})'.format(self.h, self.s, self.l)

     

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           def __str__(self):

     

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               r, g, b = self.toSrgb()

     

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               return 'rgb({}%,{}%,{}%)'.format(round(r*100), round(g*100), round(b*100))

     

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           def toSrgb(self):

     

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               hs = Srgb.fromHue(self.h)

     

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               c = (1 - abs(2 * self.l - 1)) * self.s

     

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               return Srgb(

     

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                   (hs.r - 0.5) * c + self.l,

     

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                   (hs.g - 0.5) * c + self.l,

     

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                   (hs.b - 0.5) * c + self.l

     

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               )

     

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       class Hsv:

     

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           def __init__(self, h, s, v):

     

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               self.h = float(h) % 1

     

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               self.s = float(s)

     

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               self.v = float(v)

     

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           def __iter__(self):

     

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               return iter((self.h, self.s, self.v))

     

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           def __repr__(self):

     

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               return 'HSV({}, {}, {})'.format(self.h, self.s, self.v)

     

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           def __str__(self):

     

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               r, g, b = self.toSrgb()

     

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               return 'rgb({}%,{}%,{}%)'.format(round(r*100), round(g*100), round(b*100))

     

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           def toSrgb(self):

     

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               hs = Srgb.fromHue(self.h)

     

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               c = self.v * self.s

     

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               hp = self.h * 6

     

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               x = c * (1 - abs(hp % 2 - 1))

     

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               if hp < 1:

     

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                   r1, g1, b1 = c, x, 0

     

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               elif hp < 2:

     

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                   r1, g1, b1 = x, c, 0

     

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               elif hp < 3:

     

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                   r1, g1, b1 = 0, c, x

     

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               elif hp < 4:

     

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                   r1, g1, b1 = 0, x, c

     

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               elif hp < 5:

     

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                   r1, g1, b1 = x, 0, c

     

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               else:

     

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                   r1, g1, b1 = c, 0, x

     

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               m = self.v - c

     

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               return Srgb(r1+m, g1+m, b1+m)

     

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       class Sin:

     

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           def __init__(self, h, s, l):

     

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               self.h = float(h) % 1

     

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               self.s = float(s)

     

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               self.l = float(l)

     

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           def __iter__(self):

     

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               return iter((self.h, self.s, self.l))

     

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           def __repr__(self):

     

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               return 'Sin({}, {}, {})'.format(self.h, self.s, self.l)

     

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           def __str__(self):

     

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               r, g, b = self.toSrgb()

     

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               return 'rgb({}%,{}%,{}%)'.format(round(r*100), round(g*100), round(b*100))

     

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           def toSrgb(self):

     

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               h = self.h

     

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               scale = self.s / 2

     

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               shift = self.l #* (1-2*scale)

     

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               return Srgb(

     

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                   shift + scale * math.cos(math.pi*2 * (h - 0/6)),

     

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                   shift + scale * math.cos(math.pi*2 * (h - 2/6)),

     

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                   shift + scale * math.cos(math.pi*2 * (h - 4/6)),

     

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               )

     

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       class Hcy:

     

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           HCY_WEIGHTS = Srgb.LUMA_WEIGHTS

     

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           def __init__(self, h, c, y):

     

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               self.h = float(h) % 1

     

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               self.c = float(c)

     

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               self.y = float(y)

     

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           def __iter__(self):

     

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               return iter((self.h, self.c, self.y))

     

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           def __repr__(self):

     

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               return 'HCY({}, {}, {})'.format(self.h, self.c, self.y)

     

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           def __str__(self):

     

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               r, g, b = self.toSrgb()

     

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               return 'rgb({}%,{}%,{}%)'.format(r*100, g*100, b*100)

     

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           def toSrgb(self):

     

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               hs = Srgb.fromHue(self.h)

     

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               y = hs.luma(wts=self.HCY_WEIGHTS)

     

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               c = self.c

     

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               if self.y < y:

     

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                   c *= self.y / y

     

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               elif y < 1:

     

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                   c *= (1 - self.y) / (1 - y)

     

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               return Srgb(

     

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                   (hs.r - y) * c + self.y,

     

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                   (hs.g - y) * c + self.y,

     

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                   (hs.b - y) * c + self.y,

     

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               )

     

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           @staticmethod

     

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           def _rgbToHcv(srgb):

     

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               if srgb.g < srgb.b:

     

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                   p = (srgb.b, srgb.g, -1., 2./3.)

     

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               else:

     

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                   p = (srgb.g, srgb.b, 0., -1./3.)

     

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               if srgb.r < p[0]:

     

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                   q = (p[0], p[1], p[3], srgb.r)

     

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               else:

     

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                   q = (srgb.r, p[1], p[2], p[0])

     

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               c = q[0] - min(q[3], q[1])

     

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               h = abs((q[3] - q[1]) / (6*c + 1e-10) + q[2])

     

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               return (h, c, q[0])

     

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           @classmethod

     

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           def fromSrgb(cls, srgb):

     

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               hcv = list(cls._rgbToHcv(srgb))

     

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               rw, gw, bw = cls.HCY_WEIGHTS

     

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               y = rw*srgb.r + gw*srgb.g + bw*srgb.b

     

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               hs = Srgb.fromHue(hcv[0])

     

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               z = rw*hs.r + gw*hs.g + bw*hs.b

     

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               if y < z:

     

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                   hcv[1] *= z / (y + 1e-10)

     

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               else:

     

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                   hcv[1] *= (1 - z) / (1 - y + 1e-10)

     

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               return Hcy(hcv[0], hcv[1], y)

     

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       class Cielab:

     

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           REF_WHITE = (0.95047, 1., 1.08883)

     

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           def __init__(self, l, a, b):

     

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               self.l = float(l)

     

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               self.a = float(a)

     

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               self.b = float(b)

     

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           def __iter__(self):

     

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               return iter((self.l, self.a, self.b))

     

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           def __repr__(self):

     

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               return 'CIELAB({}, {}, {})'.format(self.l, self.a, self.b)

     

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           def __str__(self):

     

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               r, g, b = self.toSrgb()

     

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               return 'rgb({}%,{}%,{}%)'.format(round(r*100), round(g*100), round(b*100))

     

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           def toSrgb(self):

     

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               inArr = np.array((*self.l,), dtype=float)

     

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               xyz = pwkit.colormaps.cielab_to_xyz(inArr, self.REF_WHITE)

     

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               linSrgb = pwkit.colormaps.xyz_to_linsrgb(xyz)

     

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               r, g, b = pwkit.colormaps.linsrgb_to_srgb(linSrgb)

     

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               return Srgb(r, g, b)

     

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           @classmethod

     

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           def fromSrgb(cls, srgb, refWhite=None):

     

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               if refWhite is None: refWhite = cls.REF_WHITE

     

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               inArr = np.array((*srgb,), dtype=float)

     

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               linSrgb = pwkit.colormaps.srgb_to_linsrgb(inArr)

     

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               xyz = pwkit.colormaps.linsrgb_to_xyz(linSrgb)

     

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               l, a, b = pwkit.colormaps.xyz_to_cielab(xyz, refWhite)

     

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               return Cielab(l, a, b)

     

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           def toSrgb(self):

     

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               inArr = np.array((self.l, self.a, self.b))

     

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               xyz = pwkit.colormaps.cielab_to_xyz(inArr, self.REF_WHITE)

     

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               linSrgb = pwkit.colormaps.xyz_to_linsrgb(xyz)

     

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               r, g, b = pwkit.colormaps.linsrgb_to_srgb(linSrgb)

     

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               return Srgb(r, g, b)

     

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