From ca9285ef96844dbb4ff45e73585bfd9172490e26 Mon Sep 17 00:00:00 2001 From: Mattias Andrée Date: Fri, 14 Feb 2014 18:06:22 +0100 Subject: split of __main__ MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Mattias Andrée --- src/curve.py | 264 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 264 insertions(+) create mode 100644 src/curve.py (limited to 'src/curve.py') diff --git a/src/curve.py b/src/curve.py new file mode 100644 index 0000000..3435124 --- /dev/null +++ b/src/curve.py @@ -0,0 +1,264 @@ +#!/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 . +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) + -- cgit v1.2.3-70-g09d2