[css-color-4] add round-trip lab values

Author: svgeesus

css-color-4/workings/Macbeth.txt

@@ -16,6 +16,11 @@ sRGB is sRGB calculated from D50 Lab with chromatic adaptation to D65
 
 nRGB is naive conversion of pso cmyk values to sRGB.
 
+lab2 is CMYK values converted back to lab
+xicclu -ff -ir PSOcoated_v3.icc
+
+sRGB2 is lab2 converted to sRGB.
+
 sample calculation:
 
 mr_lab=[51.711, 47.694, 16.857]
@@ -36,173 +41,198 @@ Array(3) [ 0.795503737776, 0.19912581837599996, 0.473224735209 ]
 ========================= data below ========================
 
 dark skin
-lab     38.358       13.802       14.646
+lab     38.358 13.802 14.646
 lch     38.358, 20.124624716997833, 46.6993622491831
 sRGB    0.45870209092590125, 0.32007132252023746, 0.26381334009797147
 pso     0.324832 0.599138 0.602548 0.485780
 nRGB    0.34718488896, 0.20613125764000007, 0.20437776744000002
+lab2    38.355787 13.718771 14.634213
 
 light skin
-lab     66.056       17.737       17.848
+lab     66.056 17.737 17.848
 lch     66.056 25.16251722304428 45.17872167764671
 sRGB    0.7801707995054818 0.5819574034194599 0.5077367244326566
 pso     0.163688 0.432714 0.425879 0.092646
 nRGB    0.7588310384479999 0.514729221244 0.520930985834
+lab2    66.129284 17.669899 17.807828
 
 blue sky
-lab     50.090        -4.407       -22.51
+lab     50.090  -4.407 -22.51
 lch     50.09 22.937343983120627 258.92276283824305
 sRGB    0.35861374256727024 0.4806652888422717 0.6165556939500282
 pso     0.668291 0.411277 0.141541 0.149605
 nRGB    0.282083675055 0.500647095585 0.730029241305
+lab2    50.117317 -4.421669 -22.509928
 
 foliage
-lab     43.204       -13.464       21.73
+lab     43.204 -13.464 21.73
 lch     43.204 25.5631022374046 121.78253045403237
 sRGB    0.3495819784053142 0.4234457970321011 0.2542085775554397
 pso     0.554549 0.256601 0.759120 0.456182
 nRGB    0.24224427191800002 0.404273757382 0.13099487984000002
+lab2    43.247288 -13.473697 21.727580
 
 blue flower
-lab     55.356         8.891       -24.82
+lab     55.356   8.891 -24.82
 lch     55.356 26.36441315485706 289.7084979581484
 sRGB    0.5129520005814212 0.5041314384420632 0.6891861857957071
 pso     0.549989 0.491789 0.062328 0.024350
 nRGB    0.43905323215000003 0.49583606215 0.9148396867999999
+lab2    55.407536 8.848533 -24.786018
 
 bluish green
-lab     70.700       -32.892       -0.24
+lab     70.700 -32.892 -0.24
 lch     70.7, 32.8928755811954, 180.4180573712323
 sRGB    0.3687923577561622, 0.7436846055136055, 0.6747488404682519
 pso     0.619655 0.000000 0.384641 0.000000
 nRGB    0.38034500000000004, 1, 0.615359
+lab2    70.628876 -32.567650 -0.106069
 
 orange
-lab     62.559       35.135       58.050
+lab     62.559 35.135 58.050
 lch     62.559, 67.85477672942413, 58.81540553823881
 sRGB    0.8737289596078436, 0.48743013287545317, 0.17203723560187653
 pso     0.030043 0.574539 0.912639 0.073987
 nRGB    0.898192791441, 0.39398241699299996, 0.08089742169300007
+lab2    62.577187 35.127123 57.970828
 
 purplish blue
-lab     40.178         9.551       -44.289
+lab     40.178   9.551 -44.289
 lch     40.178, 45.307142063917475, 282.16956757875397
 sRGB    0.27056023971670246, 0.36068663956511976, 0.6579706647059643
 pso     0.844520 0.680119 0.000000 0.000000
 nRGB    0.15547999999999995, 0.31988099999999997, 1
+lab2    39.528723 8.485752 -42.112271
 
 moderate red
-lab     51.711       47.694       16.857
+lab     51.711 47.694 16.857
 lch     51.711, 50.58533468308775, 19.46548035000572
 sRGB    0.782365578265228, 0.3299609364735502, 0.38206099086629175
 pso     0.095888 0.773688 0.462167 0.120127
 nRGB    0.795503737776, 0.19912581837599996, 0.473224735209
+lab2     51.746686 47.576278 16.846156
 
 purple
-lab     30.375       21.131       -20.30
+lab     30.375 21.131 -20.30
 lch     30.375, 29.30203339360598, 316.14905286918514
 sRGB    0.3602612680842865, 0.23316052206020216, 0.40644889811705104
 pso     0.672001 0.844106 0.160514 0.315601
 nRGB    0.22448218760100003, 0.10669369770600001, 0.574543378914
+lab2    30.411496 21.061348 -20.318246
 
 yellow green
-lab     72.492       -23.462       57.07
+lab     72.492 -23.462 57.07
 lch     72.492, 61.70454070811969, 112.34801292482507
 sRGB    0.6237512399897851, 0.7401843871288837, 0.2479420452626609
 pso     0.403959 0.032823 0.879513 0.060450
 nRGB    0.56001032155, 0.90871115035, 0.11320356085000005
+lab2    72.508214 -23.408051 57.073785
 
 orange yellow
-lab     71.963       19.486       67.998
+lab     71.963 19.486 67.998
 lch     71.963, 70.73494327416967, 74.0094313244772
 sRGB    0.9046813185631295, 0.633661174512058, 0.15251462577238098
 pso     0.026882 0.373528 0.917099 0.064206
 nRGB    0.9106379856919999, 0.586248738768, 0.07757825839400001
+lab2    71.988196 19.474792 67.954180
 
-blue
-lab     28.653       15.600       -50.52
+blue ** check pso values
+lab     28.653 15.600 -50.52
 lch     28.653, 52.87372126113312, 287.160091652553
 sRGB    0.15434596195192993, 0.24382769404212812, 0.577067166400983
 pso     1.000000 0.846365 0.000000 0.000000
 nRGB    0, 0.15363499999999997, 1
+lab2    30.757057 13.043556 -46.247492
 
 green
-lab     55.046       -38.088       31.61
+lab     55.046 -38.088 31.61
 lch     55.046, 49.496341723404164, 140.31003467778154
 sRGB    0.2638932762091318, 0.5813842341831656, 0.2868628888000584
 pso     0.713157 0.070127 0.861648 0.155189
 nRGB    0.242328121673, 0.785566939003, 0.11688129147199999
+lab2    55.076474 -38.063910 31.653426
 
 red
-lab     42.182       54.893       28.785
+lab     42.182 54.893 28.785
 lch     42.182, 61.982398098169774, 27.671788697910042
 sRGB    0.713817099436228, 0.18067207842425287, 0.22093013045788767
 pso     0.057877 0.955528 0.744658 0.237287
 nRGB    0.718569459699, 0.03391937253599997, 0.194752662846
+lab2    42.245669 54.914956 28.770983
 
 yellow
-lab     82.230         4.048       79.844
+lab     82.230   4.048 79.844
 lch     82.23, 79.94654864345301, 87.09765413971907
 sRGB    0.9404835651314826, 0.7835709856805116, 0.08810062284962886
 pso     0.022256 0.158332 0.932802 0.056649
 nRGB    0.922355780144, 0.793988349468, 0.06339130049800001
+lab2    82.274025 4.002809 79.974855
 
 magenta
-lab     51.820       49.787       -13.90
+lab     51.820 49.787 -13.90
 lch     51.82, 51.690960225168965, 344.4008329076339
 sRGB    0.7557397317132898, 0.32885676834031397, 0.5847761463440625
 pso     0.234213 0.793246 0.022206 0.012446
 nRGB    0.756256014998, 0.20418073971600004, 0.965624375876
+lab2    51.838108 49.793529 -13.890209
 
 cyan
-lab     50.555       -27.973       -28.13
+lab     50.555 -27.973 -28.13
 lch     50.555 39.67734933182911 225.1695015620979
 desat_cyan
 lch     50.555 33.7 225.1695015620979
 lab     50.555 -23.758898108744773 -23.89989039008933
 sRGB    0.0009044016966127655 0.5205697664872857 0.6288076105046994
 pso     0.797136 0.159738 0.165963 0.237161
 rRGB    0.15475257089600003, 0.6409846238179999, 0.636235951043
+lab2    50.577208 -23.813859 -24.002466
 
 white 9.5 (.05 D)
-lab     96.387        -0.404         2.238
+lab     96.387  -0.404   2.238
 lch     96.387, 2.274172376931881, 100.23273666083813
 sRGB    0.9617491586334798, 0.9596837804789503, 0.9420309128191856
 pso     0.042452 0.031800 0.055804 0.000000
 nRGB    0.957548, 0.9682, 0.944196
+lab2    96.398996 -0.425662 2.241989
 
 neutral 8 (.23 D)
-lab     81.014        -0.570         0.180
+lab     81.014  -0.570   0.180
 lch     81.014, 0.5977457653551382, 162.47443162627712
 sRGB    0.7848759799508187, 0.7900901105897526, 0.787351861664225
 pso     0.222900 0.158683 0.159239 0.025770
 nRGB    0.7570741329999999, 0.8196362609100001, 0.81909458903
+lab2    81.097257 -0.584252 0.134028
 
 neutral 6.5 (.44 D)
-lab     66.297        -0.434       -0.079
+lab     66.297  -0.434 -0.079
 lch     66.297, 0.44113149966874954, 190.3164636177376
 sRGB    0.6285501894340038, 0.6329284759216435, 0.632407706965441
 pso     0.356944 0.272657 0.260496 0.114909
 nRGB    0.569163078096, 0.643764743213, 0.6545283348640001
+lab2    66.317275 -0.432188 -0.054450
 
 neutral 5 (.70 D)
-lab     50.830        -0.687       -0.268
+lab     50.830  -0.687 -0.268
 lch     50.83, 0.7374232163418779, 201.3108507096969
 sRGB    0.4691121777258797, 0.4760603564968741, 0.47621104289127564
 pso     0.477445 0.383105 0.349081 0.289582
 nRGB    0.37123247799000003, 0.43825331211000007, 0.462424574142
+lab2    50.817427 -0.700608 -0.287514
 
 neutral 3.5 (1.05 D)
-lab     35.724        -0.521       -0.468
+lab     35.724  -0.521 -0.468
 lch     35.724, 0.7003320640953119, 221.93248294171104
 sRGB    0.32496296405417696, 0.33053531849566803, 0.3322574333971765
 pso     0.577187 0.473918 0.412416 0.524124
 nRGB    0.2012065591879999, 0.25034979783199995, 0.2796171235839999
+lab2    35.746030 -0.543022 -0.484248
 
 black 2 (1.5 D)
-lab     20.706         0.025         -0.447
+lab     20.706   0.025   -0.447
 lch     20.706, 0.44769855930078667, 273.2011270261488
 sRGB    0.19462750886077482, 0.1953957463070961, 0.1979475537592461
 pso     0.693063 0.595110 0.469317 0.802219
 nRGB    0.060706306796999954, 0.08007954909000004, 0.10495901442300004
+lab2    20.542248 -0.102405 0.326121
+