#!/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 = 'res'
# 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
Using `lambda t : divide_by_maximum(series_d(t))` as the algorithm is better than just `series_d`
@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 ciexyy_to_srgb(x, y, 1.0)
def simple_whitepoint(temperature):
'''
Calculate the colour for a blackbody temperature using a simple 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
Using `lambda t : divide_by_maximum(cmf_2deg(t))` as the algorithm is better than just `cmf_2deg`
@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
'''
global cmf_2deg_cache
if cmf_2deg_cache is None:
with open(DATADIR + '/2deg', 'rb') as file:
cmf_2deg_cache = file.read()
cmf_2deg_cache = cmf_2deg_cache.decode('utf-8', 'error').split('\n')
cmf_2deg_cache = filter(lambda x : not x == '', cmf_2deg_cache)
cmf_2deg_cache = [[float(x) for x in x_y.split(' ')] for x_y in cmf_2deg_cache]
temp = min(max(1000, temperature), 40000)
x, y = 0, 0
if (temp % 100) == 0:
(x, y) = cmf_2deg_cache[int((temp - 1000) // 100)]
else:
temp -= 1000
(x1, y1) = cmf_2deg_cache[int(temp // 100)]
(x2, y2) = cmf_2deg_cache[int(temp // 100 + 1)]
temp = (temp % 100) / 100
x = x1 * temp + x2 * (1 - temp)
y = y1 * temp + y2 * (1 - temp)
return ciexyy_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
Using `lambda t : divide_by_maximum(cmf_10deg(t))` as the algorithm is better than just `cmf_10deg`
@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
'''
global cmf_10deg_cache
if cmf_10deg_cache is None:
with open(DATADIR + '/10deg', 'rb') as file:
cmf_10deg_cache = file.read()
cmf_10deg_cache = cmf_10deg_cache.decode('utf-8', 'error').split('\n')
cmf_10deg_cache = filter(lambda x : not x == '', cmf_10deg_cache)
cmf_10deg_cache = [[float(x) for x in x_y.split(' ')] for x_y in cmf_10deg_cache]
temp = min(max(1000, temperature), 40000)
x, y = 0, 0
if (temp % 100) == 0:
(x, y) = cmf_10deg_cache[int((temp - 1000) // 100)]
else:
temp -= 1000
(x1, y1) = cmf_10deg_cache[int(temp // 100)]
(x2, y2) = cmf_10deg_cache[int(temp // 100 + 1)]
temp = (temp % 100) / 100
x = x1 * temp + x2 * (1 - temp)
y = y1 * temp + y2 * (1 - temp)
return ciexyy_to_srgb(x, y, 1)
redshift_cache, redshift_old_cache = None, None
def redshift(temperature, old_version = False, linear_interpolation = False):
'''
Calculate the colour for a blackbody temperature using same data as in the program redshift
@param temperature:float The blackbody temperature in kelvins, clipped to [1000, 25100] (100 more kelvins than in redshift)
@param old_version:bool Whether to the method used in redshift<=1.8, in which case
`temperature` is clipped to [1000, 10000] (1 more kelvin than in redshift)
@param linear_interpolation:bool Whether to interpolate one linear RGB instead of sRGB
@return :(float, float, float) The red, green and blue components of the white point
'''
global redshift_cache, redshift_old_cache
cache = None
if not old_version:
if redshift_cache is None:
with open(DATADIR + '/redshift', 'rb') as file:
redshift_cache = file.read()
redshift_cache = redshift_cache.decode('utf-8', 'error').split('\n')
redshift_cache = filter(lambda x : not x == '', redshift_cache)
redshift_cache = [[float(x) for x in r_g_b.split(' ')] for r_g_b in redshift_cache]
cache = redshift_cache
else:
if redshift_old_cache is None:
with open(DATADIR + '/redshift_old', 'rb') as file:
redshift_old_cache = file.read()
redshift_old_cache = redshift_old_cache.decode('utf-8', 'error').split('\n')
redshift_old_cache = filter(lambda x : not x == '', redshift_old_cache)
redshift_old_cache = [[float(x) for x in r_g_b.split(' ')] for r_g_b in redshift_old_cache]
cache = redshift_old_cache
temp = min(max(1000, temperature), 10000 if old_version else 25100)
r, g, b = 1, 1, 1
if (temp % 100) == 0:
(r, g, b) = cache[int((temp - 1000) // 100)]
else:
temp -= 1000
(r1, g1, b1) = cache[int(temp // 100)]
(r2, g2, b2) = cache[int(temp // 100 + 1)]
temp = (temp % 100) / 100
if linear_interpolation:
(r, g, b) = standard_to_linear(r, g, b)
r = r1 * temp + r2 * (1 - temp)
g = g1 * temp + g2 * (1 - temp)
b = b1 * temp + b2 * (1 - temp)
if linear_interpolation:
(r, g, b) = linear_to_standard(r, g, b)
return (r, g, b)
def temperature(temperature, algorithm):
'''
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`
'''
if temperature == 6500:
return
(r, g, b) = algorithm(temperature)
rgb_brightness(r, g, b)
def divide_by_maximum(rgb):
'''
Divide all colour components by the value of the most prominent colour component
@param rgb:[float, float, float] The three colour components
@return :[float, float, float] The three colour components divided by the maximum
'''
m = max([abs(x) for x in rgb])
if m != 0:
return [x / m for x in rgb]
return rgb
def clip_whitepoint(rgb):
'''
Clip all colour components to fit inside [0, 1]
@param rgb:[float, float, float] The three colour components
@return :[float, float, float] The three colour components clipped
'''
return [min(max(0, x), 1) for x in rgb]
def rgb_contrast(r, g = None, b = None):
'''
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, defaults to `r` if `None`
@param b:float? The contrast parameter for the blue curve, defaults to `r` if `None`
'''
if g is None: g = r
if b is None: b = r
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 xyY
@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]) = ciexyy_to_srgb(x, y, (Y - 0.5) * level + 0.5)
def rgb_brightness(r, g = None, b = None):
'''
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, defaults to `r` if `None`
@param b:float? The brightness parameter for the blue curve, defaults to `r` if `None`
'''
if g is None: g = r
if b is None: b = r
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 xyY
@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]) = ciexyy_to_srgb(x, y, Y * level)
def linearise():
'''
Convert the curves from formatted in standard RGB to linear RGB
'''
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
def standardise():
'''
Convert the curves from formatted in linear RGB to standard RGB
'''
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 gamma(r, g = None, b = None):
'''
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, defaults to `r` if `None`
@param b:float? The gamma parameter for the blue curve, defaults to `r` if `None`
'''
if g is None: g = r
if b is None: b = r
for (curve, level) in curves(r, g, b):
if not level == 1.0:
for i in range(i_size):
curve[i] **= 1 / level
def negative(r = True, g = None, b = None):
'''
Revese the colour curves (negative image with gamma preservation)
@param r:bool Whether to invert the red curve
@param g:bool? Whether to invert the green curve, defaults to `r` if `None`
@param b:bool? Whether to invert the blue curve, defaults to `r` if `None`
'''
if g is None: g = r
if b is None: b = r
for (curve, setting) in curves(r, g, b):
if setting:
for i in range(i_size // 2):
j = i_size - 1 - i
curve[i], curve[j] = curve[j], curve[i]
def rgb_invert(r = True, g = None, b = None):
'''
Invert the colour curves (negative image with gamma invertion), using sRGB
@param r:bool Whether to invert the red curve
@param g:bool? Whether to invert the green curve, defaults to `r` if `None`
@param b:bool? Whether to invert the blue curve, defaults to `r` if `None`
'''
if g is None: g = r
if b is None: b = r
for (curve, setting) in curves(r, g, b):
if setting:
for i in range(i_size):
curve[i] = 1 - curve[i]
def cie_invert(r = True, g = None, b = None):
'''
Invert the colour curves (negative image with gamma invertion), using CIE xyY
@param r:bool Whether to invert the red curve
@param g:bool? Whether to invert the green curve, defaults to `r` if `None`
@param b:bool? Whether to invert the blue curve, defaults to `r` if `None`
'''
if g is None: g = r
if b is None: b = r
for (curve, setting) in curves(r, g, b):
if setting:
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]) = ciexyy_to_srgb(x, y, 1 - Y)
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 rgb_limits(r_min, r_max, g_min = None, g_max = None, b_min = None, b_max = None):
'''
Changes the black point and the white point, using sRGB
@param r_min:float The red component value of the black point
@param r_max:float The red component value of the white point
@param g_min:float? The green component value of the black point, defaults to `r_min`
@param g_max:float? The green component value of the white point, defaults to `r_max`
@param b_min:float? The blue component value of the black point, defaults to `r_min`
@param b_max:float? The blue component value of the white point, defaults to `r_max`
'''
if g_min is None: g_min = r_min
if g_max is None: g_max = r_max
if b_min is None: b_min = r_min
if b_max is None: b_max = r_max
for (curve, (level_min, level_max)) in curves((r_min, r_max), (g_min, g_max), (b_min, b_max)):
if (level_min != 0) or (level_max != 1):
for i in range(i_size):
curve[i] = curve[i] * (level_max - level_min) + level_min
def cie_limits(level_min, level_max):
'''
Changes the black point and the white point, using CIE xyY
@param level_min:float The brightness of the black point
@param level_max:float The brightness of the white point
'''
if (level_min != 0) or (level_max != 1):
for i in range(i_size):
(x, y, Y) = srgb_to_ciexyy(r_curve[i], g_curve[i], b_curve[i])
Y = Y * (level_max - level_min) + level_min
(r_curve[i], g_curve[i], b_curve[i]) = ciexyy_to_srgb(x, y, Y)
def manipulate(r, g = None, b = None):
'''
Manipulate the colour curves using a lambda function
@param r:(float)→float Lambda function to manipulate the red colour curve
@param g:(float)?→float Lambda function to manipulate the green colour curve, defaults to `r` if `None`
@param b:(float)?→float Lambda function to manipulate the blue colour curve, defaults to `r` if `None`
The lambda functions thats a colour value and maps it to a new colour value.
For example, if the red value 0.5 is already mapped to 0.25, then if the function
maps 0.25 to 0.5, the red value 0.5 will revert back to being mapped to 0.5.
'''
if g is None: g = r
if b is None: b = r
for (curve, f) in curves(r, g, b):
for i in range(i_size):
curve[i] = f(curve[i])
# TODO document this elsewhere, and make it possible to have non-round x_colours
def lower_resolution(x_colours, y_colours):
'''
Emulates low colour resolution
@param x_colours:int The number of colours to emulate on the encoding axis
@param y_colours:int The number of colours to emulate on the output axis
'''
x_r = i_size / x_colours
y_r = o_size / y_colours
for curve in (r_curve, g_curve, b_curve):
for i in range(i_size):
x = int(x_r * int(i / x_r))
y = curve[x] * 2 ** 16
y = int(y_r * int(y / y_r))
curve[i] = y / 2 ** 16
def start_over():
'''
Reverts all colours curves to identity mappings.
This intended for multi-monitor setups with different curves on each monitor.
If you have a multi-monitor setups without different curves then you have not
calibrated the monitors or you have awesome monitors that support hardware
gamma correction.
'''
for i in range(i_size):
v = i / (i_size - 1)
r_curve[i] = v
g_curve[i] = v
b_curve[i] = v
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)
