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diff --git a/doc/colprof.html b/doc/colprof.html new file mode 100644 index 0000000..de9d5c2 --- /dev/null +++ b/doc/colprof.html @@ -0,0 +1,1559 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<html> + <head> + <title>colprof</title> + <meta http-equiv="content-type" content="text/html; + charset=ISO-8859-1"> + <meta name="author" content="Graeme Gill"> + </head> + <body> + <h2> profile/colprof</h2> + <h3>Summary</h3> + Create an <a href="File_Formats.html#ICC">ICC</a> profile from + the <a href="File_Formats.html#.ti3">.ti3</a> test chart patch + values.<br> + <h3>Usage Summary</h3> + <tt><small>colprof [-<i>options</i>] inoutfile<br> + <a href="#v">-v</a> + + + + + + + + + + + + Verbose mode<br> + <a href="#A">-A "manufacturer"</a> Set the + manufacturer description string<br> + <a href="#M">-M "model"</a> + Set the model + description string<br> + <a href="#D">-D "description"</a> Set the + profile Description string (Default "<span + style="font-style: italic;">inoutfile</span>")<br> + <a href="#C">-C "copyright"</a> Set the + copyright string<br> + <a href="#Za">-Z tmnb </a> + Attributes: + Transparency, Matte, Negative, BlackAndWhite<br> + </small></tt><tt><small> <a href="colprof.html#Zi">-Z prsa</a> + + Default + intent: Perceptual, Rel. Colorimetric, Saturation, Abs. + Colorimetric</small></tt><tt><br> + </tt><tt> </tt><tt><small> <a href="#q">-q lmhu</a> + Quality - Low, + Medium (def), High, Ultra<br> + <a href="#b">-b [lmhun]</a> + Low quality B2A table - or specific B2A quality or none + for input device<br> + <a href="#y">-y</a> + + + + + + + + + + + + Verify A2B profile<br> + <a href="#ni">-ni</a> + + + + + + + + + + + + Don't create input (Device) shaper + curves<br> + </small></tt><tt><small> <a href="#np">-np</a> + + Don't create input (Device) grid position curves</small></tt><tt><br> + </tt><tt> </tt><tt><small> <a href="#no">-no</a> + + + + + + + + + + + + Don't create output (PCS) shaper + curves<br> + </small></tt><tt><small> <a href="#nc">-nc</a> + + Don't put the input .ti3 data in the profile</small></tt><tt><br> + </tt><tt> </tt><tt><small> <a href="#k">-k zhxr</a> + Black generation: z = zero K,<br> + + + + + +h += +0.5 +K +(def), +x += + + + + + + + + + + + + max K, r = ramp K<br> + <a href="#kp">-k p stle stpo enpo enle shape</a><br> + + + + + +stle: +K +level +at +White +0.0 + + + + + + + + + + + + - 1.0<br> + + + + + + +stpo: +start +point +of +transition +Wh + + + + + + + + + + + + 0.0 - Bk 1.0<br> + + + + + + +enpo: +End +point +of +transition +Wh + + + + + + + + + + + + 0.0 - Bk 1.0<br> + + + + + + +enle: +K +level +at +Black + + + + + + + + + + + + 0.0 - 1.0<br> + + + + + + +shape: +1.0 += +straight, +0.0-1.0 +concave, + + + + + + + + + + + + 1.0-2.0 convex<br> + <a href="#K">-K parameters</a> + + + Same as -k, but target is K locus rather than K value itself<br> + <a href="#l">-l <i>tlimit</i></a> + override CMYK total ink limit, 0 - 400% + (default from .ti3)<br> + <a href="#L">-L <i>klimit</i></a> + override black ink limit, 0 - 100% (default + from .ti3)<br> + <a href="#a">-a lxXgsmGS</a> + Algorithm type override<br> + + + + + + +l += +Lab +cLUT +(def.), + + + + + + + + + + + + x = XYZ cLUT, X = display XYZ cLUT + matrix<br> + + + + + + +g += +gamma+matrix, +s += + + + + + + + + + + + + shaper+matrix, m = matrix only,<br> + + + + + + +G += +single +gamma+matrix, +S += + + + + + + + + + + + + single shaper+matrix<br> + <a href="#u">-u</a> + + + + + + + + If input profile, auto scale WP to allow extrapolation</small></tt><tt><br> + </tt><tt> </tt><tt><small><small> <a href="#uc">-uc</a> + + If input profile, clip cLUT values above WP<br> + </small> </small></tt><tt><small><a href="#U">-U <span + style="font-style: italic;">scale</span></a> + If input + profile, scale media white point by scale</small></tt><tt><br> + </tt><tt> </tt><tt> </tt><tt><a href="#R">-R</a></tt><tt> +Restrict +white +<= +1.0, +black +and + + + + + + + + + + + + primaries to be +ve</tt><tt><br> + </tt><tt> </tt><tt><small><small><a + href="file:///D:/src/argyll/doc/colprof.html#f">-f [<i>illum</i>]</a> + Use Fluorescent + Whitening Agent compensation [opt. simulated inst. illum.:<br> + + + M0, M1, M2, </small></small></tt><tt><small><small><small>A, + C, D50 (def.), D50M2, D65, F5, F8, F10 or file.sp ]</small></small></small></tt><tt><br> + </tt><tt><small><small><small><small> <a + href="file:///D:/src/argyll/doc/colprof.html#i">-i <i>illum</i></a> + + Choose illuminant for + computation of CIE XYZ from spectral data & FWA:<br> + + + + + + +A, +C, +D50 +(def.), +D50M2, + + D65, F5, F8, F10 or file.sp</small></small></small><br> + <a href="#o">-o <i>observ</i></a> + Choose CIE Observer for spectral data:<br> + + + + + + + + + + + + + 1931_2 </small></tt><tt><small>(def.)</small></tt><tt><small>, + 1964_10, S&B 1955_2, shaw, J&V 1978_2<br> + <a href="#r">-r avgdev</a> + Average deviation of device+instrument readings as + a percentage (default 0.5%)<br> + <a href="#s">-s src.icc</a> +Apply +gamut +mapping +to +output +profile +perceptual +B2A +table +for + + + + + + + + + + + + given source<br> + <a href="#S">-S src.icc</a> + + + + + + + + + + + + Apply gamut mapping to output profile perceptual and saturation + B2A table<br> + <a href="#nP">-nP</a> + + + + + + + + + + + + Use colormetric source gamut to make output profile perceptual + table<br> + <a href="#nS">-nS</a> + + + + + + + + + + + + Use colormetric source gamut to make output profile saturation + table<br> + <a href="#g">-g src.gam</a> + Use source image + gamut as well for output profile gamut mapping<br> + <a href="#p">-p aprof.icm,...</a> Incorporate + abstract profile(s) into output tables<br> + <a href="#t">-t intent</a> + Override gamut + mapping intent for output profile perceptual table:<br> + <a href="#T">-T intent</a> + + + + + + + + + + + + Override gamut mapping intent for output profile saturation + table:<br> + </small></tt><tt><small> + + a - Absolute Colorimetric (in Jab) [ICC Absolute Colorimetric]<br> + + aw - Absolute Colorimetric + (in Jab) with scaling to fit white point<br> + + aa - Absolute Appearance<br> + + r - White Point Matched + Appearance [ICC Relative Colorimetric]<br> + + la - Luminance matched Appearance<br> + + p - Perceptual (Preferred) [ICC + Perceptual]<br> + </small></tt><tt><small> + + + + + + + + + + + + pa - Perceptual Appearance</small></tt><tt><br> + </tt><tt> </tt><tt><small> + + + + + + + + + + + + ms - Saturation<br> + + s - Enhanced Saturation [ICC + Saturation]<br> + + al - Absolute Colorimetric (Lab)</small></tt><tt><small><br> + <a href="#c">-c viewcond</a> + + + + + + + + + + + + set input viewing conditions for output profile CIECAM02 gamut + mapping,<br> + + + + + + + + + + + + + either an enumerated choice, or a parameter<br> + <a href="#d">-d viewcond</a> + + + + + + + + + + + + set output viewing conditions for output profile CIECAM02, gamut + mapping<br> + + + + + + + + + + + + + either an enumerated choice, or a parameter:value change<br> + + + + + + + + + + + + + Also sets out of gamut clipping CAM space.<br> + + + + + + + + + + + + + Enumerated Viewing Conditions:<br> + </small></tt><tt><small> + pp - Practical Reflection Print (ISO-3664 + P2)<br> + + pe - Print evaluation environment (CIE + 116-1995)<br> + </small></tt><tt><small> + pc - Critical print evaluation + environment (ISO-3664 P1)</small></tt><tt><br> + </tt><tt> </tt><tt><small> + mt - Monitor in typical work + environment<br> + + mb - Monitor in bright work environment<br> + + md - Monitor in darkened work environment<br> + + jm - Projector in dim environment<br> + + jd - Projector in dark environment<br> + + pcd - Photo CD - original scene outdoors<br> + + ob - Original scene - Bright Outdoors<br> + + cx - Cut Sheet Transparencies on a viewing box</small></tt><tt><small><br> + + s:surround n = auto, a = average, m = + dim, d = dark,<br> + + + + + + + + + + + + + + c = transparency (default average)<br> + + + w:X:Y:Z Adapted white point + as XYZ (default media white)<br> + + + w:x:y Adapted + white point as x, y<br> + + a:adaptation Adaptatation + luminance in cd.m^2 (default 50.0)<br> + + b:background Background % + of image luminance (default 20)<br> + + l:scenewhite + Scene white in cd.m^2 if surround = auto (default 250)<br> + + + f:flare Flare light % of + image luminance (default 1)<br> + + + f:X:Y:Z Flare color as XYZ + (default media white)<br> + + + f:x:y Flare + color as x, y<br> + <a href="#P">-P</a> + + + + + + + + + + + + + Create gamut gammap_p.wrl and gammap_s.wrl diagostics<br> + </small></tt><tt><small> <a href="#O">-O outputfile</a> +Override + + + + + + + + + + + + the default output filename & extension.</small></tt><tt><br> + </tt><tt> </tt><tt><small> <a href="#p1"><i>inoutfile</i></a> + Base name for + input.ti3/output.icc file</small></tt><br> + <h3>Options<br> + </h3> + <b><a name="v"></a>-v</b> Turn on verbose mode. Gives progress + information as the profile is created. Since colprof can take a long + time to generate, this is often useful to monitor progress. If used + in combination with the <b>-y</b> flag, the error of each test + point to the resulting profile will be printed out.<br> + <br> + <a name="A"></a>The <b>-A</b> parameter allows setting of the + device manufacturer description tag. The parameter should be a + string that identifies the manufacturer of the device being + profiled. With most command line shells, it will be necessary to + enclose the parameter with double quotes, so that spaces and other + special characters are included in the parameter, and not mistaken + for the start of another flag, or as a final command line + parameters. By default no manufacturer description string tag will + be generated for the profile.<br> + <br> + <a name="M"></a>The <b>-M</b> parameter allows setting of the + device mode description tag. The parameter should be a string that + identifies the particular model of device being profiled. With most + command line shells, it will be necessary to enclose the parameter + with double quotes, so that spaces and other special characters are + included in the parameter, and not mistaken for the start of another + flag, or as a final command line parameters. By default no model + description string tag will be generated for the profile.<br> + <br> + <a name="D"></a>The <b>-D</b> parameter allows setting of the + profile description tag. The parameter should be a string that + describes the device and profile. On many systems, it will be this + string that will be used to identify the profile from a list of + possible profiles. With most command line shells, it will be + necessary to enclose the parameter with double quotes, so that + spaces and other special characters are included in the parameter, + and not mistaken for the start of another flag, or as a final + command line parameter. Many programs that deal with ICC profiles + use the description tag to identify a profile, rather than the + profile filename, so using a descriptive string is important in + being able to find a profile. By default, the base name of the + resulting profile will be used as the description.<br> + <br> + <a name="C"></a>The <b>-C</b> parameter allows setting of the + profile copyright tag. The parameter should be a string that + describes the copyright (if any) claimed on the profile being + generated.. With most command line shells, it will be necessary to + enclose the parameter with double quotes, so that spaces and other + special characters are included in the parameter, and not mistaken + for the start of another flag, or as a final command line + parameters. By default a generic copyright string will be generated + for the profile.<br> + <br> + <a name="Za"></a>The <b>-Z</b> parameter allows setting of the + profile attribute flags. There are four flags: <span + style="font-weight: bold;">t</span> to set Transparency, the + default being Reflective; <span style="font-weight: bold;">m</span> + to set Matte, the default is Glossy; <span style="font-weight: + bold;">n</span> to set Negative, the default is Positive; <span + style="font-weight: bold;">b</span> to set BlackAndWhite, the + default is Color.<br> + <br> + <a name="Zi"></a>The <b>-Z</b> parameter allows setting of the + profile default intent. The default intent can be one of the four + standard intents: <span style="font-weight: bold;">p</span> to set + Perceptual, <span style="font-weight: bold;">r</span> to set + Relative Colorimetric, <span style="font-weight: bold;">s</span> to + set Saturation, and <span style="font-weight: bold;">a</span> to + set Absolute colorimetric.<br> + <br> + <a name="q"></a> The <b>-q</b> parameter sets the level of effort + and/or detail in the resulting profile. For table based profiles + ("cLUT" profiles), it sets the main lookup table size, and hence + detail in the resulting profile. For matrix profiles it sets the per + channel curve detail level and fitting "effort". It is <span + style="text-decoration: underline;">highly recommended</span> that + <span style="font-weight: bold;">-qm</span> be used as a starting + point, and other settings only tried after this has been evaluated. + <span style="font-weight: bold;">NOTE</span> that <span + style="font-weight: bold;">-qu</span> is a <span + style="text-decoration: underline;">test mode</span>, and + shouldn't be used, except to prove that it is not worth using.<br> + <br> + <a name="b"></a> The <b>-b</b> flag overrides the <b>-q</b> + parameter, and sets the lut resolution for the BtoA (inverse) to a + low value. The creation of the B2A table is fairly time consuming, + and if the profile is only going to be used by <a + href="targen.html">targen</a>, or if it will only be used as an + input space profile, or if it will only be linked as an output + profile using Argyll's <a href="collink.html">collink</a> tool + using the <b>-G</b> option (inverse AtoB option), then a high + detail BtoA table is not required, and some time and profile space + can be saved. If the profile is to be used as an output space + profile with another CMS, or is going to be linked using the simple + (-s) or mapping mode (-g) options, then a good quality B2A table is + needed, and the -b flag should <span style="font-weight: bold;">NOT</span> + be set. Optionally, a specific B2A table quality can be set.<br> + <br> + For input devices, the presence of a B2A table is not + mandatory, and it can be omitted entirely from the profile by using + <span style="font-weight: bold;">-bn</span>. Note that input + profiles and matrix profiles will only contain a colorimetric intent + table or matrix.<br> + <br> + <a name="y"></a> The <b>-y</b> flag does a verification check on + the AtoB profile. This is done by comparing what CIE colors the + profile predicts for the test chart test patches, and comparing them + to the actual values. A summary of the average and maximum Lab delta + E's will be printed out if this flag is set. If the <b>-v</b> flag + is also set, then information for each patch will also be printed.<br> + <br> + <a name="ni"></a><a name="np"></a><a name="no"></a>Normally cLUT + base profiles are generated with three major elements:- per device + channel (shaper) input curves, the multi-dimensional lut table, and + per PCS channel (shaper) output curves. The Using the <b>-ni</b> + flag disables the creation of the per device channel curves, while + using the <b>-no</b> flag disables the creation of the per PCS + channel curves.<br> + For cLUT based profiles, the input curves that are written to the + profile are composed of two components, a shape to best match the + detailed shape of the device behavior, and a shape to distribute the + input values evenly across the LUT input indexes. The <span + style="font-weight: bold;">-no</span> flag disables the former, + while the <span style="font-weight: bold;">-np</span> flag disables + the latter. <br> + <br> + <a name="nc"></a><span style="font-weight: bold;">-nc </span>Normally +the + + + + + + + + + + + + device and CIE/spectral sample data and calibration curves used to + create a profile is stored in the <span style="font-weight: bold;">'targ'</span> + text tag in the resulting ICC profile. To suppress this and make the + resulting profile smaller, use the <span style="font-weight: bold;">-nc + + + + + + + + + + + </span>flag. <span style="font-weight: bold;">Note</span> that this + will then preclude final calibrated device value ink limits from + being computed for the resulting profile in subsequent use (ie. <a + href="collink.html">collink</a>, <a href="xicclu.html">xicclu</a> + etc.).<br> + <br> + <a name="k"></a> -<b>k</b> parameter sets the target level of black + (K) when creating a B2A CMYK output tables. This is often called a + black level, a black inking rule, black generation, or under color + removal. These set the target black level.<br> + <br> + Possible arguments to the <b>-k</b> flag are:<br> + <br> + <b> -kz</b> selects minimum black (0.0)<br> + <b> -kh</b> selects a black value of 0.5<br> + <b> -kx</b> selects the maximum possible black (1.0)<br> + <b> -kr</b> selects a linear black ramp, starting at minimum black + for highlight, and maximum black for shadow (equivalent to -kp 0 0 1 + 1 1). This is the default.<br> + <br> + <b><a name="kp"></a>-k p stle stpo enpo enle shape</b> allows + an arbitrary black value ramp to be defined, consisting of a + starting value (stle) for highlights, a breakpoint L value (stpo) + where it starts to transition to the shadow level, an end breakpoint + L (enpo) where it flattens out again, and the finishing black level + (enle) for the shadows. There is also a curve parameter, that + modifies the transition from stle to enle to either be concave + (ie. the transition starts gradually and and finished more + abruptly) using values 0.0-1.0, with 0.0 being most concave, or + convex (the transition starts more abruptly but finishes gradually), + using values 1.0-2.0, with 2.0 being the most convex.<br> + <br> + Typical black value generation curve with parameters something like: + -kp 0 .1 .9 1 .5<br> + <br> + <tt> 1.0 K | + enpo<br> + + + + + + + + + + + + + | + _______ enle<br> + + + + + + + + + + + + + | /<br> + + + + + + + + + + + + + | /<br> + + + + + + + + + + + + + | /<br> + + + + + + + + + + + + + | /<br> + + stle | ------/<br> + + +-------------------<br> + 0.0 K + 0.0 + stpo 1.0<br> + +White + + + + + + + + + + + + Black<br> + </tt> <br> + For minimum sensitivity of printed output to the lighting spectrum, + it currently seems best to use the maximum possible black, but other + black generation levels (ie. 0.3 to 0.5) may well be preferred if + one wants to minimize the noisy appearance of black on an inkjet + device, or if the banding behaviour or other rendering flaws of the + printer is to be minimized. <br> + <br> + Note that the black level curve is applied throughout the gamut, + resulting in GCR (Grey Component Replacement). There is no facility + to restrict black to just neutral colors, hence UCR is not currently + supported.<br> + <br> + The <a href="xicclu.html">xicclu</a> tool can be used to plot out + the resulting black level for a given set of parameters, by using + the <a href="xicclu.html#g">-g</a> flag of a profile already + created from the same .ti3 file.<br> + <br> + <a name="K"></a> <span style="font-weight: bold;">-K parameters.</span> + Any of the <span style="font-weight: bold;">-k</span> options above + can use the <span style="font-weight: bold;">-K</span> version, in + which rather than a black value target being defined by the inking + rule, a black <span style="text-decoration: underline;">locus</span> + target is defined. For each lookup, the minimum possible black level + and the maximum possible black level is determined, the former + corresponding to a locus target of 0, and the latter corresponding + to a locus target of 1. For instance, at the white point, no black + will be used in the output, even if the black locus specifies a + maximum (since the maximum amount of black that can be used to print + white is actually zero). Similarly, at the black point, black may + well be used, even if the black locus specifies zero black (since a + certain amount of black is needed to achieve the desired density of + color). <br> + <tt> </tt><br> + <a name="l"></a> The <b>-l</b> <i>tlimit</i> parameter sets the + total ink limit (TAC, Total Area Coverage) for the CMYK separation, + as a total percentage from 0% to 400%, and overrides any ink limit + specified in the .ti3 file. The limit value should generally be set + a little below the value used in the test chart generation, to avoid + the very edges of the gamut. If the test chart ink limit has been + chosen to be a little beyond an acceptable level, then this number + should be the acceptable level. Although limits can be set below + 200%, this will generally restrict the color gamut noticeably, as + fully saturated secondary colors will not be reproduced. Values are + between 220% and 300% for typical printing devices. Ink limits will + be in the final calibrated device values if the <span + style="font-weight: bold;">.ti3</span> includes the calibration + table.<br> + <br> + <a name="L"></a> The <b>-L</b> <i>klimit</i> parameter sets the + black channel ink limit for the CMYK separation, as a total + percentage from 0% to 100%. For printing press like devices, this + can be used to prevent the black channel screening pattern "filling + in". Typical values might be from 95% to 99%. Note that with the + current implementation this can slow down the creation of the + profile quite noticeably, so do not use <span style="font-weight: + bold;">-L</span> unless you really need to. Ink limits will be in + the final calibrated device values if the <span style="font-weight: + bold;">.ti3</span> includes the calibration table.<br> + <br> + <a name="a"></a> The <b>-a</b> parameter allows choosing an + alternate profile type. <br> + <br> + By default (equivalent to <b>-al</b>) profile creates a <span + style="font-weight: bold;">cLUT</span> based table profile with a + PCS (Profile Connection Space) of L*a*b*, which generally gives the + most accurate results, and allows for the four different rendering + intents that ICC profiles can support.<br> + <br> + A cLUT base table profile using a PCS of XYZ can be created if <b>-ax</b> + is used, and this may have the advantage of better accuracy for + additive type devices (displays, scanners, cameras etc.), may avoid + clipping for displays with a colorant chromaticity that can't be + encoded in L*a*b* PCS space, and may give a more accurate white + point for input devices by avoiding clipping of values above the + white point that can occur in L*a*b* based cLUT input profiles. By + default cLUT XYZ PCS Display profiles will also have a set of dummy + matrix tags included in them, for better compatibility with other + systems. The dummy matrix deliberately interchanges Red, Green and + Blue channels, so that it is obvious if the cLUT tables are not + being used. If it is important for both the cLUT and matrix be + accurate, use <span style="font-weight: bold;">-aX</span>, which + will create shaper/matrix tags.<br> + <br> + For RGB input or display profiles, a simpler type of profile using + either a gamma curves or a general shaper curves, combined with a + matrix can be created, although such a profile cannot support + perceptual or saturation intents. Gamma curve and matrix profiles + can be created by specifying <b>-ag</b> or <b>-aG</b>, the former + creating three independent gamma curves, one for each device + channel, and the latter creating one common curve for all the device + channels. The latter may be needed with certain applications that + will not accept different gamma curves for each channel. General + shaper curve and matrix profiles (which are superior to gamma curve + profiles) can be created by specifying <b>-as</b> or <b>-aS</b>, + the former creating three independent shaper curves, one for each + device channel, and the latter creating one common curve for all the + device channels. The latter may be needed with certain applications + that will not accept different shaper curves for each channel.<br> + <br> + The <span style="font-weight: bold;">-am</span> option will create + a matrix profile with linear (i.e. gamma = 1.0) curves. This may be + useful in creating a profile for a device that is known to have a + perfectly linear response, such as a camera in RAW mode.<br> + <br> + <a name="u"></a> <span style="font-weight: bold;">-u:</span> Input + profiles will normally be created such that the white patch of the + test chart will be mapped to perfect white when used with any of the + non-absolute colorimetric intents. This is the expected behavior for + input profiles. If such a profile is then used with a sample that + has a lighter color than the original test chart, then a cLUT + profile will clip the value, since it cannot be represented in the + lut table. Using the <b>-u</b> flag causes the media white point to + be automatically scaled (using the same type of scaling as the <span + style="font-weight: bold;">-U scale</span> option) to avoid + clipping values up to full device white. This flag can be useful + when an input profile is needed for using a scanner as a "poor mans" + colorimeter, or if the white point of the test chart doesn't + represent the white points of media that will be used in practice, + and that white point adjustment will be done individually in some + downstream application.<br> + <br> + <a name="uc"></a> <span style="font-weight: bold;">-uc:</span> For + input profiles it is sometimes desirable that any highlights + brighter than the white point, map exactly to white, and this option + post processes the cLUT entries to ensure this is the case. Note + that due to the finite nature of the cLUT grid, this may affect the + accuracy of colors near the light surface of the device gamut.<br> + <br> + <a name="U"></a><span style="font-weight: bold;"> -U <span + style="font-style: italic;">scale</span>:</span> Input profiles + will normally be created such that the white patch of the test chart + will be mapped to perfect white when used with any of the + non-absolute colorimetric intents. This is the expected behavior for + input profiles. Sometimes the test chart white is not quite the same + as the media being converted through the input profile, and it may + be desirable in these cases to adjust the input profile white point + to compensate for this. This can happen in the case of a camera + profile, where the test chart is not perfectly exposed. The <span + style="font-weight: bold;">-U</span> parameter allows this. If the + media converted is a little darker than the test chart white, then + use a scale factor slightly less than 1.0 to make sure that the + media white comes out as white on conversion (ie. try 0.9 for + instance). If the media is a little lighter than the test chart + white and is "blowing out" the highlights, try a value slightly + greater than 1.0 (ie. try 1.1 for instance). The <span + style="font-weight: bold;">-u</span> option sets the scale + automatically to accomodate a perfect white, but <span + style="font-weight: bold;">-U scale</span> can be used on top of + this automatic scaling.<br> + <br> + <a name="R"></a><span style="font-weight: bold;"> -</span><span + style="font-weight: bold;">R</span><span style="font-weight: + bold;">:</span> Normally the white point, black point and primary + locations (for matrix profiles) are computed so as to create + profiles that best match the sample data provided. Some programs are + not happy with the resulting locations if they have negative XYZ + values, or if the white point has a Y value > 1. The <span + style="font-weight: bold;">-R</span> option restricts the white, + black and primary values, so as to work with these programs, but + this will reduce the accuracy of the profile.<br> + <br> + <a name="f"></a> The <b>-f</b> flag enables Fluorescent Whitening + Agent (FWA) compensation. This only works if spectral data is + available and, the instrument is not UV filtered. FWA + compensation adjusts the spectral samples so that they appear to + have been measured using an illuminant that has a different level of + Ultra Violet to the one the instrument actually used in the + measurement. There are two ways this can be used:<br> + <br> + The first and most common is to use the <b>-f</b> flag with the <b>-i</b> + illuminant parameter, to make the color values more accurately + reflect their appearance under the viewing illuminant. This will + work accurately if you specify the <span style="text-decoration: + underline;">actual illuminant spectrum you are using to view the + print</span>, using the <span style="font-weight: bold;"><span + style="font-weight: bold;">-i</span></span> flag. If you are + doing proofing, you need to apply this to <span + style="text-decoration: underline;">both your source profile, and + your destination profile</span>. Note that it is not sufficient to + specify an illuminant with the same white point as the one you are + using, you should specify the spectrum of the illuminant you are <span + style="text-decoration: underline;">actually using</span> for the + proofing, including its <span style="text-decoration: underline;">Ultra + + + + + + + + + + + + Violet</span> spectral content, otherwise FWA compensation won't + work properly. This means you ideally need to measure your + illuminant spectrum using an instrument that can measure down to + 300nm. Such instruments are not easy to come by. The best + alternative is to use the <a href="illumread.html">illumread</a> + utility, which uses an indirect means of measuring an illuminant and + estimating its UV content. Another alternative is to simply try + different illuminant spectra in the <span style="font-weight: + bold;">ref </span>directory, and see if one gives you the result + you are after, although this will be fairly a tedious approach. The + ref/D50_X.X.sp set of illuminant spectra are the D50 spectrum with + different levels of U.V. added or subtracted, ref/D50_1.0.sp being + the standard D50 illuminant, and may be somewhere to start.<br> + [Note: Generally using <span style="font-weight: bold;">-f</span> + with the standard (<b>-i) </b>D50 illuminant spectrum will predict + that the device will produce bluer output than the default of not + FWA compensation. This is because most instruments use an + incandescent illuminant (A type illuminant), which has lower + relative levels of UV than D50, so the FWA compensation simulates + the effect of the greater UV in the D50. Also note that in an + absolute colorimetric color transformation, the more a profile + predicts the output device will have blue output, the yellower the + result will be, as the overall color correction compensates for the + blueness. The opposite will happen for an input profile.]<br> + <br> + The second way of using the <b>-f</b> flag is to provide it with a + instrument simulation illuminant spectrum parameter, in addition to + the default D50 or <b>-i</b> parameter CIE XYZ + calculation illuminant<b></b>. This more complicated scenario + simulates the measurement of the spectral reflectance of the samples + under a particular instrument illuminant, then computes the CIE XYZ + values of that reflectance spectrum under the default D50 or <b>-i</b> + parameter illuminant. This is <u>not</u> used to give a more + accurate real world result, but to provide simulations of various + standardized measurement conditions. For instance, to reproduce ISO + 13655:2009 M2 measurement conditions, the <b>-f D50M2</b> could be + used (together with the default <b>-i D50</b> setting). There are + shortcuts provided for ISO 13655:2009 conditions:<br> + <br> + <b>-f M0</b> + equivalent to<b> -f A</b><br> + <b>-f M1</b> + equivalent to<b> -f D50</b><br> + <b>-f M2</b> + equivalent to<b> -f D50M2</b><b><br> + </b><br> + Note that using <span style="font-weight: bold;">-f</span> <b>M2</b> + gives a result that is comparable to that of a U.V. cut filter + instrument. See also the discussion <a href="FWA.html">About + Fluorescent Whitening Agent compensation</a>.<br> + <br> + <a name="i"></a> The <b>-i</b> parameter allows specifying a + standard or custom illumination spectrum, applied to spectral .ti3 + data to compute PCS (Profile Connection Space) tristimulus values. <b>A</b>, + <b>D50</b>, <b>D65</b>, <b>F5</b>, <b>F8</b>, <b>F10</b> are a + selection of standard illuminant spectrums, with <b>D50</b> being + the default. If a filename is specified instead, it will be assumed + to be an Argyll specific <a href="File_Formats.html#.sp">.sp</a> + custom spectrum file. This only works if spectral data is available. + Illuminant details are:<br> + <br> + A CIE + tungsten filament lamp 2848K<br> + D50 CIE daylight 5000K<br> + D65 CIE daylight 6500K<br> + F5 CIE Fluorescent + 6350K, CRI 72<br> + F8 CIE Fluorescent + 5000K, CRI 95<br> + F10 CIE Fluorescent + 5000K, CRI 81<br> + <br> + Custom illuminants are most often used when a viewing booth or + other known viewing conditions is going to be used to view results. + Other illuminant reference files could be created using a suitable + measuring instrument such as a spectrolino, or an eyeone using <a + href="spotread.html">spotread</a>, although such instruments do + not themselves provide the necessary response down to Ultra Violet + that is needed for accurate operation of Fluorescent Whitening Agent + compensation. The best way of measuring a custom illuminant is to + use <a href="illumread.html">illumread</a>, since it uses a special + method to estimate the illuminant UV in a way that complements FWA + compensation. (See the discussion above for the <b>-f</b> flag).<br> + <br> + Note that if an illuminant other than D50 is chosen, the resulting + ICC profile will not be standard, and may not work perfectly with + other profiles that that use the standard ICC D50 illuminant, + particularly if the absolute rendering intent is used. Profiles + should generally be linked with other profiles that have the same + illuminant and observer.<br> + <br> + <a name="o"></a> The <b>-o</b> flag allows specifying a tristimulus + observer, and is used to compute tristimulus values. The following + choices are available:<br> + <b> 1931_2</b> selects the standard CIE 1931 2 degree + observer. The default.<br> + <b>1964_10</b> selects the standard CIE 1964 10 degree + observer.<br> + <b>1955_2</b> selects the Stiles and Birch 1955 2 degree + observer<br> + <b>1978_2 </b>selects the Judd and Voss 1978 2 degree + observer<br> + <b>shaw</b> selects the Shaw and Fairchild 1997 2 degree + observer<br> + <br> + Note that if an observer other than 1931 2 degree is chosen, the + resulting ICC profile will not be standard, and cannot be freely + interchanged with other profiles that that use the standard 1931 2 + degree observer. Profiles should only be linked with other profiles + that have the same illuminant and observer. The <b>1978_2</b> + observer or <span style="font-weight: bold;">shaw</span> observer + may give slightly better results than the <b>1931_2</b> observer.<br> + <br> + <br> + <a name="r"></a> The <b>-r</b> parameter specifies the average + deviation of device+instrument readings from the perfect, noiseless + values as a percentage. Knowing the uncertainty in the reproduction + and test patch reading can allow the profiling process to be + optimized in determining the behaviour of the underlying system. The + lower the uncertainty, the more each individual test reading can be + relied on to infer the underlying systems color behaviour at that + point in the device space. Conversely, the higher the uncertainty, + the less the individual readings can be relied upon, and the more + the collective response will have to be used. In effect, the higher + the uncertainty, the more the input test patch values will be + smoothed in determining the devices response. If the perfect, + noiseless test patch values had a uniformly distributed error of +/- + 1.0% added to them, then this would be an average deviation of 0.5%. + If the perfect, noiseless test patch values had a normally + distributed error with a standard deviation of 1% added to + them, then this would correspond to an average deviation of 0.564%. + For a lower quality instrument (less than say a Gretag Spectrolino + or Xrite DTP41), or a more variable device (such as a xerographic + print engine, rather than a good quality inkjet), then you might be + advised to increase the <span style="font-weight: bold;">-r</span> + parameter above its default value (double or perhaps 4x would be + good starting values.) <br> + <br> + <a name="S"></a><a name="s"></a><span style="font-weight: bold;">-s + -S </span>In order to generate perceptual and saturation + intent B2A tables for output profiles, it is necessary to specify at + least one profile to define what source gamut should be used in the + source to destination gamut mapping. [For more information on <span + style="text-decoration: underline;">why</span> a source gamut is + needed, see <a href="iccgamutmapping.html">About ICC profiles and + Gamut Mapping</a>] The <b>-S</b> parameter is used to do this, + and doing so causes perceptual and saturation tables to be + generated. If only a perceptual intent is needed, then the <b>-s</b> + flag can be used, and the saturation intent will use the same table + as the perceptual intent. Note that a input, output, display or + device colororspace profile should be specified, not a non-device + colorspace, device link, abstract or named color profile.<br> + If no source gamut is specified for a cLUT Display profile, then an + ICC Version 2.2.0 profile will be created with only an A2B0 and B2A0 + tag. If a source gamut is specified, then an ICC Version 2.4.0 + profile will be created with a full complement of B2A tags to + support all intents. The source gamut is created from the + corresponding intent table of the provided profile to the output + table being created. A TIFF or JPEG file containing an embedded ICC + profile may be supplied as the argument.<br> + <span style="font-weight: bold;">Note</span> that input profiles and + matrix profiles will only contain a colorimetric intent table or + matrix, and hence the <span style="font-weight: bold;">-s</span> + and <span style="font-weight: bold;">-S</span> option is not + relevant.<br> + <br> + <a name="nP"></a><span style="font-weight: bold;">-nP</span>: + Normally when a source profile is provided to define the source + gamut for the output profile perceptual table gamut mapping, the + perceptual source table is used to determine this gamut. This is + because some profile have gamut transformations in their perceptual + A2B tables that is not in the colorimetric A2B table, and this needs + to be taken into account in creating the perceptual B2A table, so + that when the two profiles are linked together with the perceptual + intent, the gamut mapping works as intended. The <span + style="font-weight: bold;">-nP</span> option causes the source + gamut to be taken from the source profile colorimetric table + instead, causing the perceptual gamut mapping created for the + perceptual table to be from the natural source colorspace gamut to + the output space gamut.<br> + <br> + <a name="nS"></a><span style="font-weight: bold;">-nS</span>: + Normally when a source profile is provided to define the source + gamut for the output profile saturation table gamut mapping, the + saturation source table is used to determine this gamut. This is + because some profile have gamut transformations in their saturation + A2B tables that is not in the colorimetric A2B table, and this needs + to be taken into account in creating the saturation B2A table, so + that when the two profiles are linked together with the saturation + intent, the gamut mapping works as intended. The <span + style="font-weight: bold;">-nS</span> option causes the source + gamut to be taken from the source profile colorimetric table + instead, causing the saturation gamut mapping created for the + saturation table to be from the natural source colorspace gamut to + the output space gamut.<small><span style="font-family: monospace;"></span></small><br> + <br> + <a name="g"></a>The <span style="font-weight: bold;">-g</span> flag + and its argument allow the use of a specific source gamut instead of + that of the source profile. This is to allow optimizing the gamut + mapping to a source gamut of a particular image, which can + give slightly better results that gamut mapping from the gamut of + the source colorspace. Such a source image gamut can be created + using the <a href="tiffgamut.html"> tiffgamut</a> tool. The gamut + provided to the <span style="font-weight: bold;">-g</span> <span + style="font-weight: bold;"></span> flag should be in the same + colorspace that <span style="font-weight: bold;">colprof</span> is + using internally to connect the two profiles. For all intents except + the last one (no. <span style="font-weight: bold;">7</span>), the + space should be Jab appearance space, with the viewing conditions + generally being those of the input profile viewing conditions. The + input profile will normally be the one used to create a source image + gamut using <span style="font-weight: bold;">tiffgamut</span>.<br> + <br> + <b><a name="p"></a></b>The <b>-p</b> option allows specifying one + or more abstract profiles that will be applied to the output tables, + after any gamut mapping. An abstract profile is a way of specifying + a color adjustment in a device independent way. The abstract profile + might have been created using one of the <span style="font-weight: + bold;">tweak</span> tools, such as <a href="refine.html">refine</a>.<br> + If a single abstract profile is specified, then it will be applied + to all the output tables (colorimetric, perceptual and saturation). + To specify different abstract profiles for each output table, use a + contiguous comma separated list of filenames. Omit a filename + between the commas if no abstract profile is to be applied to a + table. For instance: -<span style="font-weight: bold;">p + colabst.icm,percabst.icm,satabst.icm</span> for three different + abstract transforms, or: <span style="font-weight: bold;">-p + ,percabst.icm,</span> for just a perceptual table abstract + transform.<br> + <br> + One strategy for getting the best perceptual results with output + profile when using ICC profiles with systems that don't accept + device link profiles, is as follows: Specify a gamut mapping profile + of opposite type to the type of device being profiled, and when + linking, use the relative colorimetric intent if the two profiles + are of the same type, and perceptual intent if the two profiles are + of the opposite type. For instance, if you are creating a CMYK + output profile, specify an RGB profile for the <b>-s</b> or <b>-S</b> + parameter. If linking that profile with a CMYK source profile, use + relative colorimetric intent, or if linking with an RGB profile, use + the perceptual intent. Conversely, if creating an RGB output + profile, specify a CMYK profile for the <b>-s</b> or <b>-S</b> + parameter, and if linking that profile with an RGB source profile, + use relative colorimetric intent, or if linking with a CMYK profile, + use the perceptual intent.<br> + <br> + (Note that the perceptual and saturation table gamut mapping doesn't + make any allowance for the application of the abstract profile. This + is a bug.)<br> + <br> + <a name="t"></a><a name="T"></a><span style="font-weight: bold;"></span><span + style="font-weight: bold;"></span>Normally, the gamut mapping used + in creating the perceptual and saturation intent tables for output + profiles is set to perceptual and saturation gamut mapping (as would + be expected), but it is possible to override this default selection + for each intent using the <b>-t</b> and <b>-T</b> flags. The <b>-t</b> + flag can be used to set the gamut mapping for the perceptual table, + and the <b>-T</b> flag can be used to set the gamut mapping for the + saturation table. A more detailed description of the different + intents is given in <a href="collink.html#i">collink</a>. Note that + selecting any of the absolute intents will probably not function as + expected, since the perceptual and saturation tables are inherently + relative colorimetric in nature.<br> + <br> + <a name="c"></a><b><a name="d"></a></b>Since appearance space is + used in the gamut mapping (just as it is in <a href="collink.html"> + collink</a>), the viewing conditions for the source and + destination colorspaces should really be specified. The source + colorspace is the profile specified with the <b>-s</b> or <b>-S</b> + flag, and the destination is the profile being created. The <b>-c</b> + and <b>-d</b> options allow specification of their respective, + associated viewing conditions. The viewing condition information is + used to map the profile PCS (Profile Connection Space, which us + either XYZ or L*a*b*) color into appearance space (CIECAM02), which + is a better colorspace to do gamut mapping in. The viewing + conditions allow the conversion into appearance space to take + account of how color will be seen under particular viewing + conditions.<br> + <br> + Viewing conditions can be specified in two basic ways. One is to + select from the list of "pre canned", enumerated viewing conditions, + choosing one that is closest to the conditions that are appropriate + for the media type and situation. Alternatively, the viewing + conditions parameters can be specified individually. If both methods + are used, them the chosen enumerated condition will be used as a + base, and its parameters will then be individually overridden.<br> + <br> + Appearance space is also used to provide a space to map any + remaining out of gamut colors (after a possible gamut mapping has + been applied) into the device gamut. <br> + <br> + <b><a name="P"></a></b>The <b>-P</b> option causes diagnostic 3D <a + href="File_Formats.html#VRML">VRML</a> plots to be created that + illustrate the gamut mappings generated for the perceptual and + saturation intent tables.<br> + <br> + <a name="O"></a>The <span style="font-weight: bold;">-O</span> + parameter allows the output file name & extension to be + specified independently of the final parameter basename. Note that + the full filename must be specified, including the extension.<span + style="font-weight: bold;"></span><br> + <br> + <a name="p1"></a> The final parameter is the file base name for the + <a href="File_Formats.html#.ti3">.ti3</a> input test point data, and + the resulting <a href="File_Formats.html#ICC">ICC</a> output + profile (.icm extension on the MSWindows platform, .icc on Apple or + Unix platforms). The <span style="font-weight: bold;">-O</span> + parameter will override this default. + <h3>Discussion</h3> + Note that monochrome profiling isn't currently supported. It may be + supported sometime in the future.<br> + <br> + If the <b>-v</b> flag is used (verbose), then at the end of + creating a profile, the maximum and average fit error of the input + points to the resulting profile will be reported. This is a good + guide as to whether things have gone smoothly in creating a profile. + Depending on the type of device, and the consistency of the + readings, average errors of 5 or less, and maximum errors of 15 or + less would normally be expected. If errors are grossly higher than + this, then this is an indication that something is seriously wrong + with the device testing, or profile creation.<br> + <br> + Given a .ti3 file from a display device that contains calibration + curves (generated by <a href="dispcal.html">dispcal</a>, passed + through <a href="dispread.html">dispread</a>) and the calibration + indicates that the VideoLUTs are accessible for the device, then <span + style="font-weight: bold;">colprof</span> will convert the + calibration into a <span style="font-weight: bold;">vcgt</span> tag + in the resulting profile so that the operating system tools can + configure the display hardware appropriately, whenever the profile + is used. If the VideoLUTs are not marked as being accessible, <span + style="font-weight: bold;">colprof</span> will do nothing with the + calibration curves. In this case, to apply calibration, the curves + have to be incorporated in the subsequent workflow, either by + incorporating them into the profile using <a + href="applycal.html#p1">applycal</a>, or including them after the + profile in a <a href="cctiff.html#p2">cctiff</a> profile chain.<br> + <br> + Given a .ti3 file from a print device that contains the per-channel + calibration information (generated by <a href="printcal.html">printcal</a>, + passed through <a href="printtarg.html">printtarg</a> and <a + href="chartread.html">chartread</a>), <span style="font-weight: + bold;">colprof</span> will save this along with the .ti3 file in + the <span style="font-weight: bold;">'targ'</span> text tag in the + profile, <span style="font-weight: bold;"></span> so that + subsequent evaluation of ink limits can compute the final calibrated + device values.<br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + </body> +</html> |