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+#!/usr/bin/env python3
+
+# Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+import math
+
+from colour import *
+
+
+
+# /usr/share/blueshift
+DATADIR = '.'
+
+# Mapping input and output maximum values + 1
+i_size = 2 ** 8
+o_size = 2 ** 16
+
+# Red, green and blue curves
+r_curve = [i / (i_size - 1) for i in range(i_size)]
+g_curve = [i / (i_size - 1) for i in range(i_size)]
+b_curve = [i / (i_size - 1) for i in range(i_size)]
+
+
+
+clip_result = True
+'''
+Set to `False` if you want to allow value overflow rather than clipping,
+doing so can create visual artifacts
+'''
+
+def curves(r, g, b):
+ '''
+ Generate a tuple of curve–parameter pairs
+
+ @param r The red parameter
+ @param g The green parameter
+ @param b The blue parameter
+ @return `((r_curve, r), (g_curve, g), (b_curve, b))`
+ '''
+ return ((r_curve, r), (g_curve, g), (b_curve, b))
+
+
+def series_d(temperature):
+ '''
+ Calculate the colour for a blackbody temperature
+
+ @param temperature:float The blackbody temperature in kelvins, must be inside [4000, 7000]
+ @return :(float, float, float) The red, green and blue components of the white point
+ '''
+ x = 0
+ ks = ((0.244063, 0), (0.09911, 1), (2.9678, 2), (-4.6070, 3))
+ if temperature > 7000:
+ ks = ((0.237040, 0), (0.24748, 1), (1.9018, 2), (-2.0064, 3))
+ for (k, d) in ks:
+ x += k * 10 ** (d * 3) / temperature ** d
+ y = 2.870 * x - 3.000 * x ** 2 - 0.275
+ return ciexy_to_srgb(x, y, 1.0)
+
+def simple_whitepoint(temperature):
+ '''
+ Calculate the colour for a blackbody temperature using a simple, but inaccurate, algorithm
+
+ @param temperature:float The blackbody temperature in kelvins, not guaranteed for values outside [1000, 40000]
+ @return :(float, float, float) The red, green and blue components of the white point
+ '''
+ r, g, b = 1, 1, 1
+ temp = temperature / 100
+ if temp > 66:
+ temp -= 60
+ r = 1.292936186 * temp ** 0.1332047592
+ g = 1.129890861 * temp ** -0.0755148492
+ else:
+ g = 0.390081579 * math.log(temp) - 0.631841444
+ if temp <= 19:
+ b = 0
+ elif temp < 66:
+ b = 0.543206789 * math.log(temp - 10) - 1.196254089
+ return (r, g, b)
+
+cmf_2deg_cache = None
+def cmf_2deg(temperature):
+ '''
+ Calculate the colour for a blackbody temperature using raw CIE 1931 2 degree CMF data with interpolation
+
+ @param temperature:float The blackbody temperature in kelvins, clipped to [1000, 40000]
+ @return :(float, float, float) The red, green and blue components of the white point
+ '''
+ if cmf_2deg_cache is None:
+ with open(DATADIR + '/2deg', 'rb') as file:
+ cmf_2deg_cache = file.read()
+ cmf_2deg_cache.decode('utf-8', 'error').split('\n')
+ cmf_2deg_cache = [[float(x) for x in x_y.split(' ')] for x_y in cmf_2deg_cache]
+ temperature = min(max(0, temperature), 1000)
+ x, y = 0, 0
+ if (temp % 100) == 0:
+ (x, y) = temperature[(temp - 1000) // 100]
+ else:
+ temp -= 1000
+ (x1, y1) = temperature[temp // 100]
+ (x2, y2) = temperature[temp // 100 + 1]
+ temp = (temp % 100) / 100
+ x = x1 * temp + x2 * (1 - temp)
+ y = y1 * temp + y2 * (1 - temp)
+ return ciexy_to_srgb(x, y, 1.0)
+
+cmf_10deg_cache = None
+def cmf_10deg(temperature):
+ '''
+ Calculate the colour for a blackbody temperature using raw CIE 1964 10 degree CMF data with interpolation
+
+ @param temperature:float The blackbody temperature in kelvins, clipped to [1000, 40000]
+ @return :(float, float, float) The red, green and blue components of the white point
+ '''
+ if cmf_2deg_cache is None:
+ with open(DATADIR + '/10deg', 'rb') as file:
+ cmf_2deg_cache = file.read()
+ cmf_2deg_cache.decode('utf-8', 'error').split('\n')
+ cmf_2deg_cache = [[float(x) for x in x_y.split(' ')] for x_y in cmf_2deg_cache]
+ temperature = min(max(0, temperature), 1000)
+ x, y = 0, 0
+ if (temp % 100) == 0:
+ (x, y) = temperature[(temp - 1000) // 100]
+ else:
+ temp -= 1000
+ (x1, y1) = temperature[temp // 100]
+ (x2, y2) = temperature[temp // 100 + 1]
+ temp = (temp % 100) / 100
+ x = x1 * temp + x2 * (1 - temp)
+ y = y1 * temp + y2 * (1 - temp)
+ return ciexy_to_srgb(x, y, 1.0)
+
+
+def temperature(temperature, algorithm, linear_rgb = True):
+ '''
+ Change colour temperature according to the CIE illuminant series D
+
+ @param temperature:float The blackbody temperature in kelvins
+ @param algorithm:(float)→(float, float, float) Algorithm for calculating a white point, for example `series_d` or `simple_whitepoint`
+ @param linear_rgb:[bool] Whether to use linear RGB, otherwise sRG is used
+ '''
+ if temperature == 6500:
+ return
+ (r, g, b) = algorithm(temperature)
+ if linear_rgb:
+ for curve in (r_curve, g_curve, b_curve):
+ for i in range(i_size):
+ R, G, B = r_curve[i], g_curve[i], b_curve[i]
+ (R, G, B) = standard_to_linear(R, G, B)
+ r_curve[i], g_curve[i], b_curve[i] = R, G, B
+ rgb_brightness(r, g, b)
+ if linear_rgb:
+ for curve in (r_curve, g_curve, b_curve):
+ for i in range(i_size):
+ R, G, B = r_curve[i], g_curve[i], b_curve[i]
+ (R, G, B) = linear_to_standard(R, G, B)
+ r_curve[i], g_curve[i], b_curve[i] = R, G, B
+
+def divide_by_maximum():
+ '''
+ Divide all colour components by the value of the most prominent colour component for each colour
+ '''
+ for i in range(i_size):
+ m = max([abs(x) for x in (r_curve[i], g_curve[i], b_curve[i])])
+ if m != 0:
+ for curve in (r_curve, g_curve, b_curve):
+ curve[i] /= m
+
+def rgb_contrast(r, g, b):
+ '''
+ Apply contrast correction on the colour curves using sRGB
+
+ @param r:float The contrast parameter for the red curve
+ @param g:float The contrast parameter for the green curve
+ @param b:float The contrast parameter for the blue curve
+ '''
+ for (curve, level) in curves(r, g, b):
+ if not level == 1.0:
+ for i in range(i_size):
+ curve[i] = (curve[i] - 0.5) * level + 0.5
+
+def cie_contrast(level):
+ '''
+ Apply contrast correction on the colour curves using CIE XYZ
+
+ @param level:float The brightness parameter
+ '''
+ if not level == 1.0:
+ for i in range(i_size):
+ (x, y, Y) = srgb_to_ciexyy(r_curve[i], g_curve[i], b_curve[i])
+ (r_curve[i], g_curve[i], b_curve[i]) = to_rgb(x, y, (Y - 0.5) * level + 0.5)
+
+def rgb_brightness(r, g, b):
+ '''
+ Apply brightness correction on the colour curves using sRGB
+
+ @param r:float The brightness parameter for the red curve
+ @param g:float The brightness parameter for the green curve
+ @param b:float The brightness parameter for the blue curve
+ '''
+ for (curve, level) in curves(r, g, b):
+ if not level == 1.0:
+ for i in range(i_size):
+ curve[i] *= level
+
+def cie_brightness(level):
+ '''
+ Apply brightness correction on the colour curves using CIE XYZ
+
+ @param level:float The brightness parameter
+ '''
+ if not level == 1.0:
+ for i in range(i_size):
+ (x, y, Y) = srgb_to_ciexyy(r_curve[i], g_curve[i], b_curve[i])
+ (r_curve[i], g_curve[i], b_curve[i]) = to_rgb(x, y, Y * level)
+
+def gamma(r, g, b):
+ '''
+ Apply gamma correction on the colour curves
+
+ @param r:float The gamma parameter for the red curve
+ @param g:float The gamma parameter for the green curve
+ @param b:float The gamma parameter for the blue curve
+ '''
+ for (curve, level) in curves(r, g, b):
+ if not level == 1.0:
+ for i in range(i_size):
+ curve[i] **= level
+
+def sigmoid(r, g, b):
+ '''
+ Apply S-curve correction on the colour curves
+
+ @param r:float? The sigmoid parameter for the red curve
+ @param g:float? The sigmoid parameter for the green curve
+ @param b:float? The sigmoid parameter for the blue curve
+ '''
+ for (curve, level) in curves(r, g, b):
+ if level is not None:
+ for i in range(i_size):
+ try:
+ curve[i] = 0.5 - math.log(1 / curve[i] - 1) / level
+ except:
+ curve[i] = 0;
+
+def clip():
+ '''
+ Clip all values below the actual minimum and above actual maximums
+ '''
+ for curve in (r_curve, g_curve, b_curve):
+ for i in range(i_size):
+ curve[i] = min(max(0.0, curve[i]), 1.0)
+
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-09-20 21:29:43 +0000