13
13
the <a href="File_Formats.html#.ti3">.ti3</a> test chart patch
15
15
<h3>Usage Summary</h3>
16
<small><span style="font-family: monospace;">colprof [-</span><i
17
style="font-family: monospace;">options</i><span
18
style="font-family: monospace;">] outfile</span><br
19
style="font-family: monospace;">
20
<span style="font-family: monospace;"> </span><a
21
style="font-family: monospace;" href="#v">-v</a><span
22
style="font-family: monospace;">
25
Verbose mode</span><br
26
style="font-family: monospace;">
27
<span style="font-family: monospace;"> </span><a
28
style="font-family: monospace;" href="#A">-A "manufacturer"</a><span
29
style="font-family: monospace;"> Set the manufacturer
30
description string</span><br style="font-family: monospace;">
31
<span style="font-family: monospace;"> </span><a
32
style="font-family: monospace;" href="#M">-M "model"</a><span
33
style="font-family: monospace;">
16
<tt><small>colprof [-<i>options</i>] inoutfile<br>
17
<a href="#v">-v</a>
29
Verbose mode<br>
30
<a href="#A">-A "manufacturer"</a> Set the
31
manufacturer description string<br>
32
<a href="#M">-M "model"</a>
34
33
Set the model
35
description string</span><br style="font-family: monospace;">
36
<span style="font-family: monospace;"> </span><a
37
style="font-family: monospace;" href="#D">-D "description"</a><span
38
style="font-family: monospace;"> Set the profile
39
Description string (Default "</span><span
40
style="font-style: italic; font-family: monospace;">inoutfile</span><span
41
style="font-family: monospace;">")</span><br style="font-family:
43
<span style="font-family: monospace;"> </span><a
44
style="font-family: monospace;" href="#C">-C "copyright"</a><span
45
style="font-family: monospace;"> Set the
34
description string<br>
35
<a href="#D">-D "description"</a> Set the
36
profile Description string (Default "<span
37
style="font-style: italic;">inoutfile</span>")<br>
38
<a href="#C">-C "copyright"</a> Set the
46
39
copyright string<br>
47
<a href="#Za">-Z [tmnb]</a>
40
<a href="#Za">-Z tmnb </a>
41
Attributes:
51
42
Transparency, Matte, Negative, BlackAndWhite<br>
52
</span></small><small><span style="font-family: monospace;"> <a
53
href="colprof.html#Zi">-Z [prsa]</a>
43
</small></tt><tt><small> <a href="colprof.html#Zi">-Z prsa</a>
45
Default
57
46
intent: Perceptual, Rel. Colorimetric, Saturation, Abs.
58
Colorimetric</span></small><br style="font-family: monospace;">
59
<small><span style="font-family: monospace;"></span><span
60
style="font-family: monospace;"> </span><a
61
style="font-family: monospace;" href="#q">-q lmhu</a><span
62
style="font-family: monospace;">
63
Quality - Low, Medium (def), High, Ultra</span><br
64
style="font-family: monospace;">
65
<span style="font-family: monospace;"> </span><a
66
style="font-family: monospace;" href="#b">-b [lmhun]</a><span
67
style="font-family: monospace;">
47
Colorimetric</small></tt><tt><br>
48
</tt><tt> </tt><tt><small> <a href="#q">-q lmhu</a>
49
Quality - Low,
50
Medium (def), High, Ultra<br>
51
<a href="#b">-b [lmhun]</a>
68
52
Low quality B2A table - or specific B2A quality or none
69
for input device</span><br style="font-family: monospace;">
70
<span style="font-family: monospace;"> </span><a
71
style="font-family: monospace;" href="#y">-y</a><span
72
style="font-family: monospace;">
75
Verify A2B profile</span><br
76
style="font-family: monospace;">
77
<span style="font-family: monospace;"> </span><a
78
style="font-family: monospace;" href="#ni">-ni</a><span
79
style="font-family: monospace;">
54
<a href="#y">-y</a>
66
Verify A2B profile<br>
67
<a href="#ni">-ni</a>
82
79
Don't create input (Device) shaper
84
</span></small><small><span style="font-family: monospace;"> </span><a
85
style="font-family: monospace;" href="#np">-np</a><span
86
style="font-family: monospace;">
81
</small></tt><tt><small> <a href="#np">-np</a>
87
82
88
Don't create input (Device) grid position curves</span></small><br
89
style="font-family: monospace;">
90
<small><span style="font-family: monospace;"></span><span
91
style="font-family: monospace;"> </span><a
92
style="font-family: monospace;" href="#no">-no</a><span
93
style="font-family: monospace;">
83
Don't create input (Device) grid position curves</small></tt><tt><br>
84
</tt><tt> </tt><tt><small> <a href="#no">-no</a>
96
96
Don't create output (PCS) shaper
98
</span></small><small><span style="font-family: monospace;"> </span><a
99
style="font-family: monospace;" href="#nc">-nc</a><span
100
style="font-family: monospace;">
98
</small></tt><tt><small> <a href="#nc">-nc</a>
101
99
102
Don't put the input .ti3 data in the profile</span></small><br
103
style="font-family: monospace;">
104
<small><span style="font-family: monospace;"></span><span
105
style="font-family: monospace;"> </span><a
106
style="font-family: monospace;" href="#k">-k zhxr</a><span
107
style="font-family: monospace;">
108
Black generation: z = zero K,</span><br
109
style="font-family: monospace;">
110
<span style="font-family: monospace;">
100
Don't put the input .ti3 data in the profile</small></tt><tt><br>
101
</tt><tt> </tt><tt><small> <a href="#k">-k zhxr</a>
102
Black generation: z = zero K,<br>
103
374
445
<a href="#nP">-nP</a>
377
457
Use colormetric source gamut to make output profile perceptual
379
459
<a href="#nS">-nS</a>
382
471
Use colormetric source gamut to make output profile saturation
383
table<br style="font-family: monospace;">
384
</span><span style="font-family: monospace;"> </span><a
385
style="font-family: monospace;" href="#g">-g src.gam</a><span
386
style="font-family: monospace;">
473
<a href="#g">-g src.gam</a>
387
474
Use source image
388
gamut as well for output profile gamut mapping</span><br
389
style="font-family: monospace;">
390
<span style="font-family: monospace;"> </span><a
391
style="font-family: monospace;" href="#p">-p aprof.icm,...</a><span
392
style="font-family: monospace;"> Incorporate abstract
393
profile(s) into output tables</span><br style="font-family:
395
<span style="font-family: monospace;"> </span><a
396
style="font-family: monospace;" href="#t">-t intent</a><span
397
style="font-family: monospace;">
475
gamut as well for output profile gamut mapping<br>
476
<a href="#p">-p aprof.icm,...</a> Incorporate
477
abstract profile(s) into output tables<br>
478
<a href="#t">-t intent</a>
398
479
Override gamut
399
mapping intent for output profile perceptual table:</span><br
400
style="font-family: monospace;">
401
<span style="font-family: monospace;"> </span><a
402
style="font-family: monospace;" href="#T">-T intent</a><span
403
style="font-family: monospace;">
480
mapping intent for output profile perceptual table:<br>
481
<a href="#T">-T intent</a>
406
493
Override gamut mapping intent for output profile saturation
407
table:</span><br style="font-family: monospace;">
408
<span style="font-family: monospace;"></span></small><small><span
409
style="font-family: monospace;">
495
</small></tt><tt><small>
410
496
411
497
a - Absolute Colorimetric (in Jab) [ICC Absolute Colorimetric]<br>
412
498
413
499
aw - Absolute Colorimetric
414
(in Jab) with scaling to fit white point<br style="font-family:
416
</span><span style="font-family: monospace;">
419
aa - Absolute Appearance</span><br
420
style="font-family: monospace;">
421
<span style="font-family: monospace;">
424
r - White
425
Point Matched Appearance [ICC Relative Colorimetric]</span><br
426
style="font-family: monospace;">
427
<span style="font-family: monospace;">
430
la - Luminance matched Appearance</span><br
431
style="font-family: monospace;">
432
<span style="font-family: monospace;">
435
p - Perceptual
436
(Preferred) [ICC Perceptual]<br>
437
</span></small><small><span style="font-family: monospace;">
440
pa - Perceptual Appearance</span></small><br style="font-family:
442
<small><span style="font-family: monospace;"></span><span
443
style="font-family: monospace;">
446
ms - Saturation</span><br
447
style="font-family: monospace;">
448
<span style="font-family: monospace;">
451
s - Enhanced Saturation
452
[ICC Saturation]</span><br style="font-family: monospace;">
453
<span style="font-family: monospace;">
456
al - Absolute Colorimetric (Lab)</span></small><small><span
457
style="font-family: monospace;"></span><br style="font-family:
459
<span style="font-family: monospace;"> </span><a
460
style="font-family: monospace;" href="#c">-c viewcond</a><span
461
style="font-family: monospace;">
500
(in Jab) with scaling to fit white point<br>
501
502
aa - Absolute Appearance<br>
503
504
r - White Point Matched
505
Appearance [ICC Relative Colorimetric]<br>
506
507
la - Luminance matched Appearance<br>
508
509
p - Perceptual (Preferred) [ICC
511
</small></tt><tt><small>
523
pa - Perceptual Appearance</small></tt><tt><br>
524
</tt><tt> </tt><tt><small>
536
ms - Saturation<br>
537
538
s - Enhanced Saturation [ICC
540
541
al - Absolute Colorimetric (Lab)</small></tt><tt><small><br>
542
<a href="#c">-c viewcond</a>
464
554
set input viewing conditions for output profile CIECAM02 gamut
465
mapping,</span><br style="font-family: monospace;">
466
<span style="font-family: monospace;">
469
either an enumerated choice, or a parameter</span><br
470
style="font-family: monospace;">
471
<span style="font-family: monospace;"> </span><a
472
style="font-family: monospace;" href="#d">-d viewcond</a><span
473
style="font-family: monospace;">
556
568
either an enumerated choice, or a parameter<br>
569
<a href="#d">-d viewcond</a>
476
581
set output viewing conditions for output profile CIECAM02, gamut
477
mapping</span><br style="font-family: monospace;">
478
<span style="font-family: monospace;">
481
either an enumerated choice, or a parameter:value change</span><br
482
style="font-family: monospace;">
483
<span style="font-family: monospace;">
486
Also sets out of gamut clipping CAM space.</span><br
487
style="font-family: monospace;">
488
<span style="font-family: monospace;">
491
Enumerated Viewing Conditions:</span><br style="font-family:
493
<span style="font-family: monospace;"></span></small><small><span
494
style="font-family: monospace;">
495
pp - Practical Reflection
496
Print (ISO-3664 P2)</span><br style="font-family: monospace;">
497
<span style="font-family: monospace;">
500
pe - Print evaluation
501
environment (CIE 116-1995)<br>
502
</span></small><small><span style="font-family: monospace;">
516
P1)</span></small><br style="font-family: monospace;">
517
<small><span style="font-family: monospace;"></span><span
518
style="font-family: monospace;">
583
595
either an enumerated choice, or a parameter:value change<br>
596
608
Also sets out of gamut clipping CAM space.<br>
609
621
Enumerated Viewing Conditions:<br>
622
</small></tt><tt><small>
623
pp - Practical Reflection Print (ISO-3664
625
626
pe - Print evaluation environment (CIE
628
</small></tt><tt><small>
629
pc - Critical print evaluation
630
environment (ISO-3664 P1)</small></tt><tt><br>
631
</tt><tt> </tt><tt><small>
519
632
mt - Monitor in typical work
520
environment</span><br style="font-family: monospace;">
521
<span style="font-family: monospace;">
535
environment</span><br style="font-family: monospace;">
536
<span style="font-family: monospace;">
537
md - Monitor in
538
darkened work environment</span><br style="font-family:
540
<span style="font-family: monospace;">
541
jm - Projector in dim
542
environment</span><br style="font-family: monospace;">
543
<span style="font-family: monospace;">
544
jd - Projector in
545
dark environment</span><br style="font-family: monospace;">
546
<span style="font-family: monospace;">
547
pcd - Photo CD - original
548
scene outdoors</span><br style="font-family: monospace;">
549
<span style="font-family: monospace;">
550
ob - Original
551
scene - Bright Outdoors</span><br style="font-family:
553
<span style="font-family: monospace;">
554
cx - Cut Sheet
555
Transparencies on a viewing box</span></small><small><span
556
style="font-family: monospace;"></span><span style="font-family:
557
monospace;"></span><br style="font-family: monospace;">
558
<span style="font-family: monospace;">
559
560
s:surround n = auto, a = average, m = dim, d = dark,</span><br
561
style="font-family: monospace;">
562
<span style="font-family: monospace;">
634
635
mb - Monitor in bright work environment<br>
636
637
md - Monitor in darkened work environment<br>
638
639
jm - Projector in dim environment<br>
640
641
jd - Projector in dark environment<br>
642
643
pcd - Photo CD - original scene outdoors<br>
644
645
ob - Original scene - Bright Outdoors<br>
646
647
cx - Cut Sheet Transparencies on a viewing box</small></tt><tt><small><br>
648
649
s:surround n = auto, a = average, m =
651
565
663
566
c = transparency (default average)</span><br
567
style="font-family: monospace;">
568
<span style="font-family: monospace;">
569
664
c = transparency (default average)<br>
665
570
666
571
667
w:X:Y:Z Adapted white point
572
as XYZ (default media white)</span><br style="font-family:
574
<span style="font-family: monospace;">
583
w:x:y
590
x, y</span><br style="font-family: monospace;">
591
<span style="font-family: monospace;">
668
as XYZ (default media white)<br>
669
592
670
671
w:x:y Adapted
672
white point as x, y<br>
673
593
674
a:adaptation Adaptatation
594
luminance in cd.m^2 (default 50.0)</span><br style="font-family:
596
<span style="font-family: monospace;">
597
675
luminance in cd.m^2 (default 50.0)<br>
676
598
677
b:background Background %
599
678
of image luminance (default 20)<br>
600
679
601
680
l:scenewhite
602
Scene white in cd.m^2 if surround = auto (default 250)<br
603
style="font-family: monospace;">
604
</span><span style="font-family: monospace;">
605
681
Scene white in cd.m^2 if surround = auto (default 250)<br>
682
606
683
607
684
f:flare Flare light % of
608
image luminance (default 1)</span><br style="font-family:
610
<span style="font-family: monospace;">
611
685
image luminance (default 1)<br>
686
612
687
613
688
f:X:Y:Z Flare color as XYZ
614
(default media white)</span><br style="font-family: monospace;">
615
<span style="font-family: monospace;">
616
689
(default media white)<br>
690
617
691
618
692
f:x:y Flare
619
693
color as x, y<br>
620
694
<a href="#P">-P</a>
621
695
624
707
Create gamut gammap_p.wrl and gammap_s.wrl diagostics<br>
625
</span></small><small><span style="font-family: monospace;"> <a
626
href="#O">-O outputfile</a>
708
</small></tt><tt><small> <a href="#O">-O outputfile</a>
630
the default output filename & extension.</span></small><br
631
style="font-family: monospace;">
632
<small><span style="font-family: monospace;"></span><span
633
style="font-family: monospace;"> </span><a
634
style="font-family: monospace;" href="#p1"><i>inoutfile</i></a><span
635
style="font-family: monospace;">
636
Base name for input.ti3/output.icc file</span></small><br>
721
the default output filename & extension.</small></tt><tt><br>
722
</tt><tt> </tt><tt><small> <a href="#p1"><i>inoutfile</i></a>
723
Base name for
724
input.ti3/output.icc file</small></tt><br>
639
727
<b><a name="v"></a>-v</b> Turn on verbose mode. Gives progress
937
1102
useful in creating a profile for a device that is known to have a
938
1103
perfectly linear response, such as a camera in RAW mode.<br>
940
<a name="u"></a> <span style="font-weight: bold;">-u:</span> Iinput
941
profiles will normally be created such that the white point of the
942
test chart, will be mapped to perfect white when used with any of
943
the non-absolute colorimetric intents. This is the expected
944
behaviour for input profiles. If such a profile is then used with a
945
sample that has a lighter color than the original test chart, then a
946
cLUT profile will clip the value, since it cannot be represented in
947
the lut table. Using the <b>-u</b> flag causes the input profile to
948
be constructed so that the profile model contains absolute color
949
values, and the white of the test chart will map to its absolute
950
reflectance value, and any values of higher reflectance than that,
951
will not be clipped by a cLut profile, with values outside the
952
reflectance range of the test chart being extrapolated. The profile
953
effectively operates in an absolute intent mode, irrespective
954
of what intent is selected when it is used. This flag can be useful
1105
<a name="u"></a> <span style="font-weight: bold;">-u:</span> Input
1106
profiles will normally be created such that the white patch of the
1107
test chart will be mapped to perfect white when used with any of the
1108
non-absolute colorimetric intents. This is the expected behavior for
1109
input profiles. If such a profile is then used with a sample that
1110
has a lighter color than the original test chart, then a cLUT
1111
profile will clip the value, since it cannot be represented in the
1112
lut table. Using the <b>-u</b> flag causes the media white point to
1113
be automatically scaled (using the same type of scaling as the <span
1114
style="font-weight: bold;">-U scale</span> option) to avoid
1115
clipping values up to full device white. This flag can be useful
955
1116
when an input profile is needed for using a scanner as a "poor mans"
956
1117
colorimeter, or if the white point of the test chart doesn't
957
1118
represent the white points of media that will be used in practice,
958
1119
and that white point adjustment will be done individually in some
959
1120
downstream application.<br>
961
<a name="un"></a><span style="font-weight: bold;">-un</span>: By
962
default a cLUT input profile with the <span style="font-weight:
963
bold;">-u</span> flag set will extrapolate values beyond the test
964
chart white and black points, and to improve the plausibility of the
965
extrapolation, a special matrix model will be created that is used
966
to add a perfect device white and perfect device black test point to
967
the set of test patches. Selecting <span style="font-weight:
968
bold;">-un</span> disables the addition of these extra
969
extrapolated white and black patches.<br>
1122
<a name="uc"></a> <span style="font-weight: bold;">-uc:</span> For
1123
input profiles it is sometimes desirable that any highlights
1124
brighter than the white point, map exactly to white, and this option
1125
post processes the cLUT entries to ensure this is the case. Note
1126
that due to the finite nature of the cLUT grid, this may affect the
1127
accuracy of colors near the light surface of the device gamut.<br>
971
1129
<a name="U"></a><span style="font-weight: bold;"> -U <span
972
1130
style="font-style: italic;">scale</span>:</span> Input profiles
973
will normally be created such that the white point of the test
974
chart, will be mapped to perfect white when used with any of the
1131
will normally be created such that the white patch of the test chart
1132
will be mapped to perfect white when used with any of the
975
1133
non-absolute colorimetric intents. This is the expected behavior for
976
1134
input profiles. Sometimes the test chart white is not quite the same
977
1135
as the media being converted through the input profile, and it may
997
1159
black and primary values, so as to work with these programs, but
998
1160
this will reduce the accuracy of the profile.<br>
1000
<a name="i"></a> The <b>-i</b> flag allows specifying a standard or
1001
custom illumination spectrum, applied to spectral .ti3 data to
1002
compute PCS (Profile Connection Space) tristimulus values. <b>A</b>,
1162
<a name="f"></a> The <b>-f</b> flag enables Fluorescent Whitening
1163
Agent (FWA) compensation. This only works if spectral data is
1164
available and, the instrument is not UV filtered. FWA
1165
compensation adjusts the spectral samples so that they appear to
1166
have been measured using an illuminant that has a different level of
1167
Ultra Violet to the one the instrument actually used in the
1168
measurement. There are two ways this can be used:<br>
1170
The first and most common is to use the <b>-f</b> flag with the <b>-i</b>
1171
illuminant parameter, to make the color values more accurately
1172
reflect their appearance under the viewing illuminant. This will
1173
work accurately if you specify the <span style="text-decoration:
1174
underline;">actual illuminant spectrum you are using to view the
1175
print</span>, using the <span style="font-weight: bold;"><span
1176
style="font-weight: bold;">-i</span></span> flag. If you are
1177
doing proofing, you need to apply this to <span
1178
style="text-decoration: underline;">both your source profile, and
1179
your destination profile</span>. Note that it is not sufficient to
1180
specify an illuminant with the same white point as the one you are
1181
using, you should specify the spectrum of the illuminant you are <span
1182
style="text-decoration: underline;">actually using</span> for the
1183
proofing, including its <span style="text-decoration: underline;">Ultra
1195
Violet</span> spectral content, otherwise FWA compensation won't
1196
work properly. This means you ideally need to measure your
1197
illuminant spectrum using an instrument that can measure down to
1198
300nm. Such instruments are not easy to come by. The best
1199
alternative is to use the <a href="illumread.html">illumread</a>
1200
utility, which uses an indirect means of measuring an illuminant and
1201
estimating its UV content. Another alternative is to simply try
1202
different illuminant spectra in the <span style="font-weight:
1203
bold;">ref </span>directory, and see if one gives you the result
1204
you are after, although this will be fairly a tedious approach. The
1205
ref/D50_X.X.sp set of illuminant spectra are the D50 spectrum with
1206
different levels of U.V. added or subtracted, ref/D50_1.0.sp being
1207
the standard D50 illuminant, and may be somewhere to start.<br>
1208
[Note: Generally using <span style="font-weight: bold;">-f</span>
1209
with the standard (<b>-i) </b>D50 illuminant spectrum will predict
1210
that the device will produce bluer output than the default of not
1211
FWA compensation. This is because most instruments use an
1212
incandescent illuminant (A type illuminant), which has lower
1213
relative levels of UV than D50, so the FWA compensation simulates
1214
the effect of the greater UV in the D50. Also note that in an
1215
absolute colorimetric color transformation, the more a profile
1216
predicts the output device will have blue output, the yellower the
1217
result will be, as the overall color correction compensates for the
1218
blueness. The opposite will happen for an input profile.]<br>
1220
The second way of using the <b>-f</b> flag is to provide it with a
1221
instrument simulation illuminant spectrum parameter, in addition to
1222
the default D50 or <b>-i</b> parameter CIE XYZ
1223
calculation illuminant<b></b>. This more complicated scenario
1224
simulates the measurement of the spectral reflectance of the samples
1225
under a particular instrument illuminant, then computes the CIE XYZ
1226
values of that reflectance spectrum under the default D50 or <b>-i</b>
1227
parameter illuminant. This is <u>not</u> used to give a more
1228
accurate real world result, but to provide simulations of various
1229
standardized measurement conditions. For instance, to reproduce ISO
1230
13655:2009 M2 measurement conditions, the <b>-f D50M2</b> could be
1231
used (together with the default <b>-i D50</b> setting). There are
1232
shortcuts provided for ISO 13655:2009 conditions:<br>
1234
<b>-f M0</b>
1235
equivalent to<b> -f A</b><br>
1236
<b>-f M1</b>
1237
equivalent to<b> -f D50</b><br>
1238
<b>-f M2</b>
1239
equivalent to<b> -f D50M2</b><b><br>
1241
Note that using <span style="font-weight: bold;">-f</span> <b>M2</b>
1242
gives a result that is comparable to that of a U.V. cut filter
1243
instrument. See also the discussion <a href="FWA.html">About
1244
Fluorescent Whitening Agent compensation</a>.<br>
1246
<a name="i"></a> The <b>-i</b> parameter allows specifying a
1247
standard or custom illumination spectrum, applied to spectral .ti3
1248
data to compute PCS (Profile Connection Space) tristimulus values. <b>A</b>,
1003
1249
<b>D50</b>, <b>D65</b>, <b>F5</b>, <b>F8</b>, <b>F10</b> are a
1004
1250
selection of standard illuminant spectrums, with <b>D50</b> being
1005
1251
the default. If a filename is specified instead, it will be assumed
1054
1305
observer or <span style="font-weight: bold;">shaw</span> observer
1055
1306
may give slightly better results than the <b>1931_2</b> observer.<br>
1057
<a name="f"></a> The <b>-f</b> flag enables Fluorescent Whitening
1058
Agent (FWA) compensation. This only works if spectral data is
1059
available, and allows the effects of different levels of Ultra
1060
Violet in the viewing illuminant from that used by the instrument,
1061
be compensated for. This will only work accurately if you specify
1062
the <span style="text-decoration: underline;">actual illuminant
1063
spectrum you are using to view the print</span>, using the <span
1064
style="font-weight: bold;"><span style="font-weight: bold;">-i</span></span>
1065
flag. If you are doing proofing, you need to apply this to <span
1066
style="text-decoration: underline;">both your source profile, and
1067
your destination profile</span>. Note that it is not sufficient to
1068
specify an illuminant with the same white point as the one you are
1069
using, you should specify the spectrum of the illuminant you are <span
1070
style="text-decoration: underline;">actually using</span> for the
1071
proofing, including its <span style="text-decoration: underline;">Ultra
1074
Violet</span> spectral content, otherwise FWA compensation won't
1075
work properly (but see the note above about non-standard illuminants
1076
and observers). This means you ideally need to measure your
1077
illuminant spectrum using an instrument that can measure down to
1078
300nm. Such instruments are not easy to come by. The best
1079
alternative is to use the <a href="illumread.html">illumread</a>
1080
utility, which uses an indirect means of measuring an illuminant and
1081
estimating its UV content. Another alternative is to simply try
1082
different illuminant spectra in the <span style="font-weight:
1083
bold;">ref </span>directory, and see if one gives you the result
1084
you are after, although this will be fairly a tedious approach. The
1085
ref/D50_X.X.sp set of illuminant spectra are the D50 spectrum with
1086
different levels of U.V. added or subtracted, ref/D50_1.0.sp being
1087
the standard D50 illuminant, and may be somewhere to start. Note
1088
that using the ref/D50_0.0.sp spectrum with <span
1089
style="font-weight: bold;">-f</span> gives a result that is
1090
comparable to that of a U.V. cut filter. See also the discussion <a
1091
href="FWA.html">About Fluorescent Whitening Agent compensation</a>.<br>
1092
[Note: Generally using <span style="font-weight: bold;">-f</span>
1093
with the standard D50 illuminant spectrum will predict that the
1094
device will produce bluer output than the default of not FWA
1095
compensation. This is because most instruments use an incandescent
1096
illuminant, which has lower relative levels of UV than D50, so the
1097
FWA compensation simulates the effect of the greater U.V. in the
1098
D50. Also note that in an absolute colorimetric color
1099
transformation, the more a profile predicts the output device will
1100
have blue output, the yellower the result will be, as the overall
1101
color correction compensates for the blueness. The opposite will
1102
happen for an input profile.]<br>
1104
1309
<a name="r"></a> The <b>-r</b> parameter specifies the average
1105
1310
deviation of device+instrument readings from the perfect, noiseless
added
removed
doc/colprof.html
