[CATs] recalc Bradford with consistent D65 D50 values

scripts/RGB_matrix_maker.py

@@ -0,0 +1,124 @@
+"""Calculate XYZ conversion matrices."""
+"""Derived from https://gist.githubusercontent.com/facelessuser/7d3707734fa9bcf208ab4dabea830cdb/raw/52a6effaec9b8b3662d28cd1378799639d1b4ef7/matrix_calc.py """
+import numpy as np
+
+np.set_printoptions(precision=17, suppress='true', sign='-', floatmode='fixed')
+
+"""From ASTM E308-01"""
+""" white_d65 = [0.95047, 1.00000, 1.08883]"""
+
+""" white_d50 = [0.96422, 1.00000, 0.82521]"""
+
+""" From CIE 15:2004 table T.3 chromaticities"""
+
+"""white_d65 = [0.31272 / 0.32903, 1.00000, (1.0 - 0.31272 - 0.32903) / 0.32903]"""
+
+"""white_d50 = [0.34567 / 0.35851, 1.00000, (1.0 - 0.34567 - 0.35851) / 0.35851]"""
+
+""" From CIE 15:2004 table T.3 XYZ"""
+
+"""white_d65 = [0.9504, 1.0000, 1.0888]"""
+
+"""white_d50 = [0.9642, 1.0000, 0.8251]"""
+
+"""The four-digit chromaticity ones that everyone uses, including the sRGB standard, for compatibility"""
+
+white_d65 = [0.3127 / 0.3290, 1.00000, (1.0 - 0.3127 - 0.3290) / 0.3290]
+white_d50 = [0.3457 / 0.3585, 1.00000, (1.0 - 0.3457 - 0.3585) / 0.3585]
+
+
+def get_matrix(wp, space):
+    """Get the matrices for the specified space."""
+
+    if space == 'srgb':
+        xr = 0.64
+        yr = 0.33
+        xg = 0.30
+        yg = 0.60
+        xb = 0.15
+        yb = 0.06
+    elif space == 'display-p3':
+        xr = 0.68
+        yr = 0.32
+        xg = 0.265
+        yg = 0.69
+        xb = 0.150
+        yb = 0.060
+    elif space == 'rec2020':
+        xr = 0.708
+        yr = 0.292
+        xg = 0.17
+        yg = 0.797
+        xb = 0.131
+        yb = 0.046
+    elif space == 'a98-rgb':
+        xr = 0.64
+        yr = 0.33
+        xg = 0.21
+        yg = 0.71
+        xb = 0.15
+        yb = 0.06
+    elif space == 'prophoto-rgb':
+        xr = 0.734699
+        yr = 0.265301
+        xg = 0.159597
+        yg = 0.840403
+        xb = 0.036598
+        yb = 0.000105
+    else:
+        raise ValueError
+
+    m = [
+        [xr / yr, 1.0, (1.0 - xr - yr) / yr],
+        [xg / yg, 1.0, (1.0 - xg - yg) / yg],
+        [xb / yb, 1.0, (1.0 - xb - yb) / yb]
+    ]
+    mi = np.linalg.inv(m)
+
+    r, g, b = np.dot(wp, mi)
+    rgb = [
+        [r],
+        [g],
+        [b]
+    ]
+    rgb2xyz = np.multiply(rgb, m).transpose()
+    xyz2rgb = np.linalg.inv(rgb2xyz)
+
+    return rgb2xyz, xyz2rgb
+
+
+if __name__ == "__main__":
+    print('===== sRGB =====')
+    to_xyz, from_xyz = get_matrix(white_d65, 'srgb')
+    print('--- rgb -> xyz ---')
+    print(to_xyz)
+    print('--- xyz -> rgb ---')
+    print(from_xyz)
+
+    print('===== Display P3 =====')
+    to_xyz, from_xyz = get_matrix(white_d65, 'display-p3')
+    print('--- rgb -> xyz ---')
+    print(to_xyz)
+    print('--- xyz -> rgb ---')
+    print(from_xyz)
+
+    print('===== Adobe 98 =====')
+    to_xyz, from_xyz = get_matrix(white_d65, 'a98-rgb')
+    print('--- rgb -> xyz ---')
+    print(to_xyz)
+    print('--- xyz -> rgb ---')
+    print(from_xyz)
+
+    print('===== Rec.2020 =====')
+    to_xyz, from_xyz = get_matrix(white_d65, 'rec2020')
+    print('--- rgb -> xyz ---')
+    print(to_xyz)
+    print('--- xyz -> rgb ---')
+    print(from_xyz)
+
+    print('===== ProPhoto =====')
+    to_xyz, from_xyz = get_matrix(white_d50, 'prophoto-rgb')
+    print('--- rgb -> xyz ---')
+    print(to_xyz)
+    print('--- xyz -> rgb ---')
+    print(from_xyz)

src/color.js

@@ -537,17 +537,29 @@ export default class Color {
 		if (!env.M) {
 			if (env.W1 === Color.whites.D65 && env.W2 === Color.whites.D50) {
 				// Linear Bradford CAT
+				// env.M = [
+				// 	[ 1.0478112,  0.0228866, -0.0501270],
+				// 	[ 0.0295424,  0.9904844, -0.0170491],
+				// 	[-0.0092345,  0.0150436,  0.7521316]
+				// ];
+
 				env.M = [
-					[ 1.0478112,  0.0228866, -0.0501270],
-					[ 0.0295424,  0.9904844, -0.0170491],
-					[-0.0092345,  0.0150436,  0.7521316]
+					[  1.0479298208405488,    0.022946793341019088,  -0.05019222954313557 ],
+					[  0.029627815688159344,  0.990434484573249,     -0.01707382502938514 ],
+					[ -0.009243058152591178,  0.015055144896577895,   0.7518742899580008  ]
 				];
 			}
 			else if (env.W1 === Color.whites.D50 && env.W2 === Color.whites.D65) {
+				// env.M = [
+				// 	[ 0.9555766, -0.0230393,  0.0631636],
+				// 	[-0.0282895,  1.0099416,  0.0210077],
+				// 	[ 0.0122982, -0.0204830,  1.3299098]
+				// ];
+
 				env.M = [
-					[ 0.9555766, -0.0230393,  0.0631636],
-					[-0.0282895,  1.0099416,  0.0210077],
-					[ 0.0122982, -0.0204830,  1.3299098]
+					[  0.9554734527042182,   -0.023098536874261423,  0.0632593086610217   ],
+					[ -0.028369706963208136,  1.0099954580058226,    0.021041398966943008 ],
+					[  0.012314001688319899, -0.020507696433477912,  1.3303659366080753   ]
 				];
 			}
 		}