chartread

From 22f703cab05b7cd368f4de9e03991b7664dc5022 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Mon, 1 Sep 2014 13:56:46 +0200 Subject: Initial import of argyll version 1.5.1-8 --- doc/chartread.html | 499 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 499 insertions(+) create mode 100644 doc/chartread.html (limited to 'doc/chartread.html') diff --git a/doc/chartread.html b/doc/chartread.html new file mode 100644 index 0000000..18d0144 --- /dev/null +++ b/doc/chartread.html @@ -0,0 +1,499 @@ + + + + chartread + + + + +

spectro/chartread

Summary

+ Read a printer test chart using an instrument, to create a .ti3 data file. The type of + instrument is determined by the communication port selected.
+
+ chartread can also be used + to read transmission values, and to read display values manually.
+

Usage

+ chartread [-options] + outfile
+ -v             + + +Verbose + + + mode
+ -c listno    +     Set communication port from the following + list (default 1)
+ -t              +   +Use +transmission + + + measurement mode
+ -d +                 +Use +display +measurement + + + mode (white Y relative results)
+ -y X +               + + + Display type - instrument specific list to choose from.
+ -e                 +Use +emissive +measurement + + + mode (absolute results)
+ -p +                 +Measure +patch +by + + + patch rather than strip
+ -x [lx]            +Take +external +values, + + + either L*a*b* (-xl) or XYZ (-xx).
+ -n             + + +Don't + + + save spectral information (default saves spectral)
+ -l +             + Save CIE as D50 L*a*b* rather than XYZ
+ -L +             + Save CIE as D50 L*a*b* as well as XYZ
+ -r                 +Resume +reading +partly + + + read chart
+ -I + file.cal        Override + calibration info from .ti2 in resulting .ti3
+ -F filter          + + + Set filter configuration:
+ + n                  + + + None
+ + p                  + + + Polarising filter
+ + 6                  + + + D65
+ + u                  + + + U.V. Cut
+ -N +              +    Disable initial calibration of instrument unless + essential
+ -B +              +    Disable auto bi-directional strip recognition
+ -H +              +    Use high resolution spectrum mode (if available)
+ -X file.ccmx          + + + + Apply Colorimeter Correction Matrix
+ -X + file.ccss          +Use +Colorimeter +Calibration +Spectral +Samples + + + + for calibration
+ -Q observ +        Choose CIE Observer for + spectral data or CCSS instrument:
+             + + + +    1931_2 (def.), 1964_10, S&B 1955_2, shaw, + J&V 1978_2
+ -T ratio           +Modify +strip +patch + + + consistency tolerance by ratio (if available)
+ -S                 +Suppress +wrong +strip + + + & unexpected value warnings
+ -W n|h|x           +Override + + + serial port flow control: n = none, h = HW, x = Xon/Xoff
+ -D [level] +         Print debug + diagnostics to stderr
+ inoutfile         + + + Base name for input[.ti2]/output[.ti3] file
+

Usage Details

+ The -v flag causes extra information to be + printed out during chartread operation.
+
+ Normally instruments are connected via a serial + communication port, and the port used should be selected by + supplying the correct parameter to the -c flag. If you + invoke chartread so as to + display the usage information (i.e. "chartread -?" or "chartread + --"), then the discovered serial ports will be listed on Windows and + Mac OSX systems.
+
+ If using an Xrite DTP41T, and printing onto + transparent or back lit media, use the -t flag to operate + the instrument in transparency mode. If using a Spectrolino or + Eye-One Pro (handheld), this triggers a fake transparency mode, that + uses a separate backlight (such as a light box). The + instrument will be used to calibrate the level of backlight, and use + this to compute the transparency of the test chart samples. Note + that for good transparency values, the backlight level needs to be + neither too bright not too dark, should ideally be incandescent + rather than fluorescent (since fluorescent lights often have big + dips in their spectrum), and ideally should be of uniform brightness + over the measurement area. If using the SpectroScanT, the -t flag operates the instrument + in transparency mode, each reading being manually triggered.
+
+ The -d flag + allows measuring in display mode using instruments that support this + mode, with the brightness normalized to the white patch value in the + test chart. While the brightness values are then relative to the + white, the readings are otherwise absolute. This corresponds to the + raw ICC absolute readings created by dispread, + and is the mode that should be used for creating a normal display + ICC profile using manual, spot by spot readings. This can be useful + if the display cannot be driven directly by the computer, but can be + made manually to display the test charts.
+
+ The -y + flag allows setting the Display Type. The selection typically + determines two aspects of of the instrument operation: 1) It may set the measuring mode + to suite refresh or non-refresh displays. + Typically only LCD (Liquid Crystal) displays have a non-refresh + nature. 2) It may select an + instrument calibration matrix suitable for a particular display + type. The selections available depends on the type and model of + instrument, and a list of the options for the discovered instruments + will be shown in the usage + information. For more details on what particular instruments support + and how this works, see Operation of + particular instruments. 3) Any installed CCSS files + (if applicable), or CCMX files. These files are typically created + using ccxxmake, and installed using oeminst. The default and Base Calibration + types will be indicated in the usage.
+
+ If using an instrument that supports an emissive + measurement mode (such as the Spectrolino), then the -e flag enables this measurement + mode, and the values recorded will be absolute XYZ values. This can + be used for media such as backlit film, measuring it on a lightbox, + so as to capture the actual illumination characteristics of that + particular media. An adaptive integration time will be used in + devices that support it.
+
+ The -p + flag causes chartread to use a spot read mode for an instrument, + even if it is capable of faster chart reading modes such as strip + reading. This can be useful if strip measurement patch recognition + is not reliable for certain media.
+
+ The -x + flag causes chartread to expect values to be entered for each + reading, rather than using an instrument to do the + measurements. This mode is ideal if your instrument is not + supported by Argyll. Either XYZ or L*a*b* values can be entered, + depending on what option follows -l, -lx to specify XYZ values, or -ll to specify L*a*b* values. + XYZ values are expected to be scaled to a maximum of 100. It is + possible to navigate about the test values being measured, so as to + do them in any order, as well as re-do values, in case of any + mistakes.
+
+ -n By + default spectral information as well as D50 standard observer XYZ + values will be recorded for each test patch, when such readings are + available from a device. The spectral readings allow for choosing a + non-standard viewing illuminant, a non-standard observer model, or + the use of the Fluorescent Paper Whitener Additive compensation when + creating the profile. If the spectral readings are not needed, then + prinread operation can be speeded up by specifying the -n + flag.
+
+ -l By + default D50 standard observer XYZ values will be recorded for each + test patch, but if the -l flag is used, D50 + L*a*b* values will be recorded instead.
+
+ -L By + default D50 standard observer XYZ values will be recorded for each + test patch, but if the -L flag is used, XYZ and D50 L*a*b* values will + be recorded.
+
+ -r By + default chartread reads the chart from scratch each time. When + reading a chart using a strip instrument or patch by patch you can + choose to finish chartread without reading all the patches, and + whatever patches have been read will be saved to the output .ti3 + file. You can then resume + reading the patches by using the -r + flag, in which case chartread will read the .ti3 file and set the + patches to those previously read values, allowing any unread patches + to then be read, or to re-read previously read patches.
+
+ -I file.cal Normally per + channel calibration curves are added to the .ti2 file using the printtarg -K or -I options, so that they will be + passed on to the .ti3 file by chartread, so that colprof + is able to correctly compute total ink limits. Where the calibration + is being applied in a workflow with native calibration capability though, it is + sometimes convenient to re-use a profile chart with different + calibration curves without going through the process of using printtarg to re-create it. This + would mean though, that the calibration information and subsequent + ink limit calculations wouldn't be accurate. To overcome this and + allow such a scenario, the chartread + + -I parameter allows overriding the .ti2 calibration curves + placed in the resulting .ti3 file with the actual calibration that + was used for that particular print.
+
+ The -F options allows configuring the + instrument to have a particular filter fitted to it. Some + instruments (i.e. the Gretag Spectrolino) allow the fitting of + various filters, such as a polarizing filter, D65 illuminant + simulation, or Ultra Violet Cut filter, and this option allows the + instrument to be configured appropriately.
+
+ -N Any + instrument that requires regular calibration will ask for + calibration on initial start-up. Sometimes this can be awkward if + the instrument is being mounted in some sort of measuring jig, or + annoying if several sets of readings are being taken in quick + succession. The -N + suppresses this initial calibration if a valid and not timed out + previous calibration is recorded in the instrument or on the host + computer. It is advisable to only use this option on the second and + subsequent measurements in a single session.
+
+ -B Some + strip instruments (i.e.. Eye-One Pro, Color Munki) when used with + Argyll will automatically recognize a strip when read in the reverse + direction by matching the patch readings against their expected + values. If the randomized patch layout has not been used, or the + expected values are not known accurately enough, this may cause + erroneous reverse recognition, so the -B flag + allows this to be turned off, forcing strips to only be read in the + forward direction.
+
+ The -H + option turns on high resolution spectral mode, if the instrument + supports it. See Operation of particular + instruments for more details.
+
+ The -X file.ccmx option reads + a Colorimeter Correction Matrix + from the given file, and applies it to the colorimeter instruments + readings. This can improve a colorimeters accuracy for a particular + type of display. A list of contributed ccmx files is here.
+
+ The -X file.ccss option reads + a Colorimeter Calibration + Spectral Sample from the given file, and uses it to set the + colorimeter instruments calibration. This will only work with + colorimeters that rely on sensor spectral sensitivity calibration + information (ie. the X-Rite i1d3, + or the DataColor Spyder4).This +can +improve +a + + + colorimeters accuracy for a particular type of display.
+
+ The -T ratio + argument modifies the patch consistency tolerance threshold for some + strip reading instruments (ie. the Eye-One Pro). In recognizing + patches in a strip, an instrument may take multiple readings as the + strip is read, and then divide the readings up into each patch. It + may then check the consistency of the multiple readings + corresponding to each patch, and reject the measurement if they are + too inconsistent. For some media (ie. a coarser screens, fabric + etc.) the default tolerance may be unreasonably tight, so the -T ratio argument can be used to + modify this criteria. To loosen the tolerance, use a number greater + than 1.0 (ie. 1.5, 2.0).
+
+ The -Q flag allows specifying a tristimulus + observer for a colorimeter when using CCSS instrument calibration + capability. The following choices are available:
+ 1931_2 selects the standard CIE 1931 2 degree + observer. The default.
+ 1964_10 selects the standard CIE 1964 10 degree + observer.
+ 1955_2 selects the Stiles and Birch 1955 2 degree + observer
+ 1978_2 selects the Judd and Voss 1978 2 degree + observer
+ shaw selects the Shaw and Fairchild 1997 2 degree + observer
+
+ The -S flag causes the normal "wrong strip" + and "unexpected value" warnings to be suppressed. There may be a lot + of these warnings if the expected patch value in the .ti2 file is in + fact far from the values actually being measured. It is probably + advisable to also use the -B + flag if warnings are turned off, since many warnings indicate that + the expected values are not to be relied on. With warnings + suppressed, greater care must be taken to read the correct strip.
+
+ The -W n|h|x + parameter overrides the default serial communications flow control + setting. The value n turns + all flow control off, h + sets hardware handshaking, and x + sets Xon/Xoff handshaking. This commend may be useful in workaround + serial communications issues with some systems and cables.
+
+ The -D flag causes communications and other + instrument diagnostics to be printed to stdout. A level can be set + between 1 .. 9, that may give progressively more verbose + information, depending on the instrument. This can be useful in + tracking down why an instrument can't connect.
+
+ The inoutfile parameters should be the + base name of the .ti2 file, and chartread will output an .ti3 that + has the same basename and the .ti3 extension. If the incoming .ti2 + file contains per-channel calibration curves, these will be passed + through to the .ti3 so that accurate ink limits can be computed + during profiling.
+
+

Discussion

+ For information about the operation of different instruments, see Operation of particular instruments.
+
+
+ + -- cgit v1.2.3