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
        manually entered 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
      -A N|A|X|G        
        XRGA conversion (default N)
     -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 manually 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.
    
    The -A options allows overriding the default
    or environment variable set XRGA
    conversion:
    
        -A N|A|X|G
    
            The N argument sets
    the calibration to Native (default).
            The A argument sets
    the calibration to XRGA.
            The X argument sets
    the calibration to XRDI.
            The G argument sets
    the calibration to GMDI.
    
     -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 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. (Note that the DTP20 always allows
    bi-directional strip reading.) If the randomized patch layout has
    not been used, then  bi-directional strip recognition will
    automatically turned off, and a warning issued if the -B flag is not
    used.
    
     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 &
      Spyder 5).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. If
    the randomized patch layout has not been used, then "wrong strip"
    warnings will automatically be suppressed, and bi-directional strip
    recognition turned off.
    
    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.