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diff --git a/doc/refine.html b/doc/refine.html new file mode 100644 index 0000000..cfe18b9 --- /dev/null +++ b/doc/refine.html @@ -0,0 +1,354 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<html> + <head> + <title>refine</title> + <meta http-equiv="content-type" content="text/html; + charset=ISO-8859-1"> + <meta name="author" content="Graeme Gill"> + </head> + <body> + <h2><b>tweak/refine</b></h2> + <h3>Summary</h3> + <span style="font-weight: bold;">Refine</span> creates an abstract + profile, by comparing CIE measurement values from two test charts. + The charts will usually be in <a href="File_Formats.html#.ti3">.ti3</a> + format, but only XYZ, Lab or spectral values will be used (ie. all + device space values are ignored). Typically the charts would be + printed on a target system (the one being emulated, say a printing + press), and the proofing system (the one that is being profiled). + The abstract profile that <span style="font-weight: bold;">refine</span> + produces will be a correction that makes the proofing system behave + more like the target. This can then be used to recreate the proofing + systems ICC profile, or device link. By feeding a previous abstract + correction profile in as well, iterative improvement can be made to + the proofing reproduction.<br> + <br> + <a href="verify.html">verify</a> is a useful tool to use on the two + test charts, to check how well the refinement is proceeding. If a + white point relative match is being created (refine -R), then use + veryify -N.<br> + <h3>Usage Summary</h3> + <tt><small>usage: refine [-options] cietarget ciecurrent [outdevicc] + [inabs] outabs<br> + -v + + Verbose<br> + -c +Create + + initial abstract correction profile<br> + -g +Don't + + impose output device gamut limit<br> + -r res Set + abstract profile clut resolution (default 33)<br> + -d factor Override default damping + factor (default 0.950000)<br> + -R +Aim + + for white point relative match rather than absolute<br> + </small></tt><tt><small><small></small><small><small>-f + [illum] Use Fluorescent Whitening Agent + compensation [opt. simulated inst. illum.:<br> + + + + M0, M1, M2, A, C, D50 (def.), D50M2, D65, F5, F8, F10 or + file.sp]<br> + -i illum 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><br> + -o observ Choose CIE Observer for + spectral data:<br> + +1931_2, + + 1964_10, S&B 1955_2, J&V 1978_2 (def.)<br> + <span style="font-style: italic;">cietarget </span> + Target CIE or spectral values, CGATS file (e.g. .ti3)<br> + <span style="font-style: italic;">ciecurrent</span> + Actual CIE or spectral values, CGATS file (e.g. .ti3)<br> + [<span style="font-style: italic;">outdevicc</span>] + Output device ICC profile to set gamut limit (not used if -g)<br> + [<span style="font-style: italic;">inabs</span>] +Previous + + abstract correction ICC profile (not used if -c)<br> + <span style="font-style: italic;">outabs</span> +Created/refined + + abstract correction ICC profile</small></tt><br> + <h3>Usage Details</h3> + <b>refine</b> provides a way of improving the profile accuracy of a + proofing system.<br> + <br> + The <b>-v</b> flag prints out extra information during the + checking, and prints each patch value, rather than just a summary.<br> + <br> + The <b>-c</b> option is used when refine is being used for the + first time, and there is no previous abstract profile to continue + refining. If <span style="font-weight: bold;">-c</span> is used, + then the name of the previous abstract correction profile should not + be supplied.<br> + <br> + If the <b>-g </b>flag indicates that an output device profile is + not being supplied, and that corrections should be attempted, even + if the colors are outside the devices gamut. Normally an output + device profile is supplied, and corrections aren't applied to colors + outside the devices gamut, since this will not achieve anything + useful, and can distort the results.<br> + <br> + If the <b>-r </b>parameter overrides the resolution of the CLUT + grid used in the abstract profile. By default the value is 33, but + other<br> + values can be chosen. An odd number is recommended. <br> + <br> + If the <b>-d </b>parameter sets how aggressively refine should try + and correct errors. Normally it will try and exactly compensate for + the color errors revealed in comparing the two measurement files, + but if the device behaviour is unusual, or not very repeatable, this + may result in successive applications of refine making things worse, + rather than better. If this is the case, try using a smaller number, + such as 0.8, or 0.5.<br> + <br> + If the <span style="font-weight: bold;">-R</span> flag is used, + then refine creates an abstract profile for improving the match of + the patch values when interpreted in a white point relative + (ie. Relative Colorimetric) intent. If used to create a corrected + device link profile using <a href="collink.html">collink</a>, + remember to create a Relative colorimetric intent device link + profile.<br> + <br> + 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. The optional + illumination parameter allows specifying a standard or custom + illumination spectrum to be used as the similated instrument + illuminant, overriding the default <b>D50</b> or CIE computation + illuminant used for FWA (see <b>-i</b> below<b>). </b>See <a + href="file:///D:/src/argyll/doc/colprof.html#f">colprof -f</a> for + a fuller explanation. The same value should be used as was used + during the creation of the profile.<br> + <br> + The <b>-i</b> flag allows specifying a standard or custom + illumination spectrum, applied to the spectral test point values to + compute CIE tristimulus values. <b>A</b>, <b>D50</b>, <b>D50M2, + 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:///D:/src/argyll/doc/File_Formats.html#.sp">.sp</a> + spectrum file. If FWA compensation is used during measurement, this + illuminant will be used by default as the simulated instrument + illuminant. The same value should be used as was used during the + creation of the profile.<br> + <br> + The <b>-o</b> flag allows specifying a tristimulus observer, and is + used to compute CIE tristimulus values. The following choices are + available:<br> + <b> 1931_2</b> selects the standard CIE 1931 2 degree + observer.<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> + If both CIE and spectral values are present in the input files, the + CIE values will be used by default. Using the <span + style="font-weight: bold;">-i</span>, <span style="font-weight: + bold;">-o</span> or <span style="font-weight: bold;">-f</span> + flag will force spectral values to be used. The the <span + style="font-weight: bold;">-i</span>, <span style="font-weight: + bold;">-o</span> or <span style="font-weight: bold;">-f</span> + flags will apply to both the target and measured input files.<br> + <br> + <span style="font-style: italic; font-weight: bold;">cietarget</span> +Is + + the filename of the target CIE or spectral values. This is a <a + href="File_Formats.html#CGATS">CGATS</a> file (e.g. a <a + href="File_Formats.html#.ti3">.ti3</a> made using <a + href="chartread.html">chartread</a>). These are the color values + wanted for each patch in the test chart, typically the product of + the target print system.<br> + <br> + <span style="font-style: italic; font-weight: bold;">ciecurrent</span> + Is the filename of the + actual, current measured CIE or spectral values. This is a <a + href="File_Formats.html#CGATS">CGATS</a> file (e.g. a <a + href="File_Formats.html#.ti3">.ti3</a> made using <a + href="chartread.html">chartread</a>). The errors between these + patches and the patches in the <span style="font-style: italic; + font-weight: bold;">cietarget</span> file will be used to create a + correction profile.<br> + <br> + [<span style="font-style: italic; font-weight: bold;">outdevicc</span>] +If + + the <span style="font-weight: bold;">-g</span> flag is not used, + then the output device ICC profile should be supplied here, to allow + <span style="font-weight: bold;">refine</span> to limit its + corrections to colors that are within the gamut of the device.<br> + <br> + [<span style="font-weight: bold; font-style: italic;">inabs</span>] +After + + the first correction has been created, subsequent corrections need + to improve upon previous ones, so the previous correction profile + should be provided here. For the first correction, the <span + style="font-weight: bold;">-c</span> flag should be used, and this + argument is omitted.<br> + <br> + <span style="font-weight: bold; font-style: italic;">outabs</span> +The + + name of the created or refined abstract correction ICC profile<br> + <br> + <h3> Discussion</h3> + <span style="font-weight: bold;">Refine</span> is typically used in + a proofing situation, in which a verification chart is being used to + check the accuracy of a proofing system. (It might also be used for + more arbitrary color alterations by created two test chart files by + hand.) By using the errors between the target chart and the measured + values, refine attempts to improve the match between the proofing + system and its target.<br> + <br> + There is facility in <a href="collink.html">collink</a>, <a + href="colprof.html">colprof</a> and <a href="revfix.html">revfix</a> + to incorporate an abstract profile. <br> + <br> + For systems using two device profiles or a device link to convert + between the target space printing files and the proofing device + space, the following would be a typical scenario:<br> + <br> + <div style="margin-left: 40px;">We have a reference set of test + chart values, read from the target system <span + style="font-weight: bold;">reference.ti3</span>. The ICC profile + for the target system is <span style="font-weight: bold;">target.icm</span>. + The ICC profile for the proofing system is <span + style="font-weight: bold;">proofer.icm</span>. If using a device + link, the device link used to print proofer test charts is + currently <span style="font-weight: bold;">target_proofer.icm</span>:<br> + <br> + <br> + First we print the test chart out on the proofing system and read + it in, resulting in a <span style="font-weight: bold;">chart1.ti3</span> + file.<br> + <br> + Lets check how well the proofing system current matches using + verify:<br> + <br> + verify reference.ti3 chart1.ti3<br> + <br> + We then create our initial abstract correction fix profile <span + style="font-weight: bold;">fix1.icm</span> using refine:<br> + <br> + refine -v -c reference.ti3 chart1.ti3 + proofer.icm fix1.icm<br> + <br> + Applying this to your process for creating the proofer device + profile or target to proofing device link (choose one of the three + options below, depending whether you are using the proofer profile + and just want to alter its colorimetric B2A table using <span + style="font-weight: bold;">revfix</span>, whether you are going + to recreate the proofer file from the original measurement data + using <span style="font-weight: bold;">colprof</span>, or + whether you are using a device link profile created using <span + style="font-weight: bold;">collink</span>):<br> + <br> + revfix -v -1 -ke -p fix1.icm proofer.icm + proofer_fix1.icm<br> + or<br> + copy proofer.ti3 proofer_fix1.ti3<br> + colprof -v -p fix1.icm proofer_fix1<br> + or<br> + collink -v -s -ia -oa -p fix1.icm target.icm + proofer.icm target_proofer_fix1.icm<br> + <br> + Note that the above example is a simple one - you should use all + the same options as you used to create your initial <span + style="font-weight: bold;"><span style="font-weight: bold;"></span>proofer.icm + + </span>or <span style="font-weight: bold;">target_proofer.icm</span>, + with the addition of the "-p fix1.icm" option to specify the + abstract correction profile be applied.<br> + <br> + Use the <span style="font-weight: bold;">proofer_fix1.icm</span> + or <span style="font-weight: bold;">target_proofer_fix1.icm</span> + to print out the test chart again, and read it in, resulting in <span + style="font-weight: bold;">chart2.ti3</span> file.<br> + <br> + Lets check how well the proofing system matches after this first + round of refinement using verify:<br> + <br> + verify reference.ti3 chart2.ti3<br> + <br> + <br> + <span style="font-weight: bold;"><span style="font-weight: bold;">>>></span></span><br> + <span style="font-weight: bold;"><span style="font-weight: bold;"></span></span><br> + <span style="font-weight: bold;"><span style="font-weight: bold;"> </span></span>We +can + + then start another round of improvement:<br> + <br> + We refine our previous abstract correction fix profile using + refine:<br> + <br> + refine -v reference.ti3 chart2.ti3 + proofer.icm fix1.icm fix2.icm<br> + <br> + Applying this new abstract profile to our process for creating the + proofing device profile or link again:<br> + <br> + revfix -v -1 -ke -p fix2.icm proofer.icm + proofer_fix2.icm<br> + or<br> + copy proofer.ti3 proofer_fix2.ti3<br> + colprof -v -p fix2.icm proofer_fix2<br> + or<br> + collink -v -s -ia -oa -p fix2.icm target.icm + proofer.icm target_proofer_fix2.icm<br> + <br> + Use the <span style="font-weight: bold;">proofer_fix2.icm</span> + or <span style="font-weight: bold;">target_proofer_fix2.icm</span> + to print out the test chart again, and read it in, resulting in <span + style="font-weight: bold;">chart3.ti3</span> file.<br> + <br> + Check again how well the proofing system matches after this first + round of refinement using verify:<br> + <br> + verify reference.ti3 chart3.ti3<br> + <br> + Rounds of improvements can be continues by looping back to <span + style="font-weight: bold;">>>></span>, being careful to + increment the names of the <span style="font-weight: bold;">fixN.icm</span>, + + <span style="font-weight: bold;">proofer_fixN.icm</span> or <span + style="font-weight: bold;">target_proofer_fixN.icm</span> and <span + style="font-weight: bold;">chartN.ti3</span>files. Stop when + exhausted, or if it looks like things are getting worse, rather + than better. If the latter happens, it might be good to revert to + the results from a previous round.<br> + </div> + <br> + <br> + <br> + <br> + <br> + <br> + <br> + </body> +</html> |