Argyll Usage Scenarios

In some situation there is no access to a displays VideoLUT + hardware, and this hardware is what is usually used to implement + display calibration. This could be because the display is being + accessed via a web server, or because the driver or windowing + system doesn't support VideoLUT access.
+

1) Don't attempt to calibrate, just profile the display.
+ 2) Calibrate, but incorporate the calibration in some other + way in the workflow.
+

2a) Use dispcal to create a calibration and a quick profile + that incorporates the calibration into the profile.
+ 2b) Use dispcal to create the calibration, then dispread and + colprof to create a profile, and then incorporate the calibration + into the profile using applycal.
+ 2c) Use dispcal to create the calibration, then dispread and + colprof to create a profile, and then apply the calibration after + the profile in a cctiff workflow.
+

The first case requires nothing special, use dispcal in a normal + fashioned with the -o + option to generate a quick profile.The profile created will not contain a 'vcgt' + tag, but instead will have the calibration curves incorporated + into the profile itself. If calibration parameters are chosen that + change the displays white point or brightness, then this will + result in a slightly unusual profile that has a white point that + does not correspond with device R=G=B=1.0. Some systems may not + cope properly with this type of profile, and a general shift in + white point through such a profile can create an odd looking + display if it is applied to images but not to other elements on + the display say as GUI decoration elements or other application + windows.
+

In the second case, the calibration file created using dispcal + should be provided to dispread using the -K flag:
+

Create the profile as + usual using colprof. but note that colprof will ignore the + calibration, and that no 'vcgt' tag will be added to the profile.
+ You can then use applycal to combine + the calibration into the profile. Note that the resulting profile + will be slightly unusual, since the profile is not made completely + consistent with the effects of the calibration, and the device + R=G=B=1.0 probably not longer corresponds with the PCS white or + the white point.
+

Profiling Scanners and other input devices + such as cameras
+

Types of test charts

Taking readings from a scanner or camera
+

For an IT8.7/2 chart, this is the ref/it8.cht file + supplied with Argyll, and the manufacturer will will supply + an individual or batch average file along with the chart + containing this information, or downloadable from their web site. + For instance, Kodak Q60 target reference files are here.
+ NOTE that the reference file for the IT8.7/2 chart supplied with Monaco EZcolor can be + obtained by unzipping the .mrf file. (You may have to make a copy + of the file with a .zip extension to do this.)
+
+ For the ColorChecker 24 patch chart, the ref/ColorChecker.cht file + should be used, and there is also a ref/ColorChecker.cie file provided that is based + on the manufacturers reference values for the chart. You can also + create your own reference file using an instrument and chartread, + making use of the chart reference file ref/ColorChecker.ti2:
+    chartread -n -a + ColorChecker.ti2
+ Note that due to the small number of patches, a profile created + from such a chart is not likely to be very detailed.
+
+ For the ColorChecker DC chart, the ref/ColorCheckerDC.cht file should be used, and + there will be a ColorCheckerDC reference file supplied by + X-Rite/GretagMacbeth with the chart.
+
+ The ColorChecker SG is relatively expensive, but is preferred by + many people because (like the ColorChecker and ColorCheckerDC) its + colors are composed of multiple different pigments, giving it + reflective spectra that are more representative of the real world, + unlike many other charts that are created out of combination of 3 + or 4 colorants.
+ A limited CIE reference file is available from X-Rite here, + but it is not in the usual CGATS format. To convert it to a CIE + reference file useful for scanin, + you will need to edit the X-Rite file using a plain text editor, + first deleting everything before the line starting with "A1" and + everything after "N10", then prepending this + + + + + + + + header, and appending this footer, + making sure there are no blank lines inserted in the process.
+ If you do happen to have access to a more comprehensive instrument + measurement of the ColorChecker SG, or you have measured it + yourself using a color instrument,
+ then you may + need to convert the reference information from spectral ColorCheckerSG.txt file to CIE + value ColorCheckerSG.cie + reference file, follow the following steps:
+      txt2ti3 + ColorCheckerSG.txt ColorCheckerSG
+      spec2cie + ColorCheckerSG.ti3 ColorCheckerSG.cie
+
+ For the Eye-One Pro Scan Target 1.4 chart, the ref/i1_RGB_Scan_1.4.cht + file should be used, and as there is no reference file + accompanying this chart, the chart needs to be read with an + instrument (usually the Eye-One Pro). This can be done using + chartread, making use of the chart reference file ref/i1_RGB_Scan_1.4.ti2:
+     chartread -n -a + i1_RGB_Scan_1.4
+ and then rename the resulting i1_RGB_Scan_1.4.ti3 + file to i1_RGB_Scan_1.4.cie
+
+ For the HutchColor HCT chart, the ref/Hutchcolor.cht + file should be used, and the reference .txt file downloaded from the HutchColor website.
+
+ For the Christophe Métairie's Digital TargeT 003 chart with + 285 patches, the ref/CMP_DT_003.cht + file should be used, and the cie reference files come with the chart.
+
+ For the Christophe Métairie's Digital Target-3 chart with + 570 patches, the ref/CMP_Digital_Target-3.cht + file should be used, and the cie reference files come with the chart.
+
+ For the LaserSoft DCPro chart, the ref/LaserSoftDCPro.cht file should be used, and + reference .txt file + downloaded from the Silverfast + website.
+
+ For the Datacolor SpyderCheckr, the ref/SpyderChecker.cht file should be used, and a + reference ref/SpyderChecker.cie + file made from measuring a sample chart is also available. + Alternately you could create your own reference file by + transcribing the values + on the Datacolor website.
+
+ For the QPCard 201, the ref/QPcard_201.cht + file should be used, and a reference ref/QPcard_201.cie file made from measuring a + sample chart is also available.
+
+ For the QPCard 202, the ref/QPcard_202.cht + file should be used, and a reference ref/QPcard_202.cie file made from measuring a + sample chart is also available.
+