spectro/dispread
Summary
Display test patches on a monitor, read the colorimetric value result
with the colorimeter, and create the chart readings file. The type of
instrument is determined by the communication port
selected. Emission and display measurement instruments are supported.
If you want to read a display manually rather than automatically, see chartread and the -d
option.
Usage
dispread [-options] inoutfile
-v
Verbose mode
-display displayname [X11 only] Choose X11 display name
-d n[,m]
[X11
only]Choose the display from the following list (default 1),
and optionally choose a different display m for VideoLUT access.
-d
n
Choose the display from the following list (default 1)
-c listno
Set
communication port from the following list (default 1)
-y c|l
Display type, c = CRT, l = LCD
-k
file.cal
Apply
display calibration file while reading
-s
Save spectral information (default don't save)
-P ho,vo,ss
Position
test window and scale it
ho,vi: 0.0 = left/top, 0.5 = center, 1.0 = right/bottom etc.
ss: 0.5 = half, 1.0 = normal, 2.0 = double etc.
-F
Fill whole screen with black background
-n
[X11 only] Don't set override redirect on test
window
-K
Run calibration first
-N
Disable auto calibration of instrument
-H
Use high resolution spectrum mode (if
available)
-V
Use adaptive measurement mode (if available)
-C "command"
Invoke shell "command" each
time a color is set
-M "command"
Invoke shell "command" each
time a color is measured
-W
n|h|x
Ovride serial port flow control: n = none, h = HW, x = Xon/Xoff
-D [level]
Print debug
diagnostics to stderr
inoutfile
Base name for input[.ti1]/output[.ti3] file.
Examples
dispread -c1 -i92 mycrt
Comments
This is the utility for exercising a display, in order to measure its
color characteristics. The device test colors are defined by the
outfile.ti1 file, while the resulting device+colorimetric and optional
spectral readings are stored in the outfile.ti3 file. Display
calibration curves can be applied during the measurements, and the
curves included in the resulting .ti3 data file using the -kflag. See dispcal
for information on how to calibrate the display before profiling
it. For best results, you should run this
against a neutral grey desktop background, and avoid having any bright
images or windows on the screen at the time you run it.
The -v flag reports progress information.
-display:
When running on a UNIX based system that used the
X11
Windowing
System, dispread
will by default use the $DISPLAY environment variable to determine
which display and screen to read from. This can be overridden by
supplying an X11 display name to the -display
option. Note that if Xinerama is active, you can't select the screen
using $DISPLAY or -display, you have to select it using the -d parameter.
-d: By
default the main display will be the location of
the test window. If the system has more than
one display or screen, an alternate display/screen can be selected with
the -d parameter. If you
invoke dispread
so as to display the usage
information (i.e. "dispcal -?" or "dispcal --"), then the discovered
displays/screens will be listed. Multiple displays may not be listed,
if they appear as a single display to the operating system (ie. the
multi-display support is hidden in the video card driver). On UNIX
based system that used the X11
Windowing
System, the -d parameter will
override the screen specified by the $DISPLAY or -display parameter.
Note that if a calibration file
is provided using the -k
option, and the VideoLUTs for a display are not accessible, dispread
will issue a warning , but will continue to run without initialising
the VideoLUTs . This could be because you are trying to access
a remote display, and the remote display doesn't support the
XF86VidMode extension, or perhaps you are running multiple monitors
using NVidia TwinView, or MergedFB, and trying to access anything other
than the primary monitor. TwinView and MergedFB don't properly support
the XF86VidMode extension for multiple displays. Xinerama does properly
support calibration of multiple displays. You can use dispwin -r to test whether the VideoLUTs are
accessible for a particular display. See also below, on how to select a
different display for VideoLUT access.
Because of the difficulty cause by TwinView and
MergedFB in X11 based systems, you can optionally specify a separate
display number after the display that is going to be used to present
test patches, for accessing the VideoLUT hardware. This must be
specified as a single string, e.g. -d
1,2
. Some experimentation may be needed using dispwin
on such systems, to discover what
screen has access to the VideoLUT hardware, and which screens the test
patches appear on. You may be able to calibrate one screen, and then
share the calibration with another screen. Profiling can be done
independently to calibration.
-c: The
instrument is assumed to communicate through a
USB or serial communication port, and the port can be selected with the
-c
option,
if the instrument is not connected to the first port. If you invoke dispread
so as to display the usage
information (i.e. "dispread -?" or "dispread --"), then the discovered
USB and serial ports will be listed. On
UNIX/Linux, a list of all possible serial ports are shown, but not all
of them may
actually be present on your system.
-y:
Display type. Colorimeters can
do a more accurate job if they know what type of display technology
they are measuring. Use -yc if
you are
calibrating a CRT (Cathode Ray Tube) type monitor or Plasma type
display, and use -yl if you
are calibrating an LCD
(Liquid Crystal Display).
-s: By default
only the colorimetric information (XYZ
value)
will be saved, but for instruments that support spectral readings (such
as
the Gretag Spectrolino), the -s option will save the spectral
readings
to the .ti3 file as well.
-k: If a
display video lookup table calibration .cal
file is provided, it will be
applied to the display while the measurements are being taken, and also
included in the resulting .ti3 data file, so that colprof can include it as a vcgt tag in the resulting
profile. The calibration file has usually been created using dispcal. If a calibration file is not created,
then the display will be read in whatever calibration state it is in.
The -P
parameter allows you to position and size the test patch window. By
default it is places in the center of the screen, and sized
appropriately for the type of instrument. The ho and vo
values govern the horizontal and vertical offset respectively. A value
of 0.0 positions the window to the far left or top of the screen, a
value of 0.5 positions it in the center of the screen (the default),
and 1.0 positions it to the far right or bottom of the screen. The ss
parameter is a scale factor for the test window size. A value of 0.5
for instance, would produce a half sized window. A value of 2.0 will
produce a double size window. Note that the ho,vo,ss numbers must be
specified as a single string (no space between the numbers and the
comma). For example, to create a double sized test window at the top
right of the screen, use -P 1,0,2
.
The -F
flag causes the while screen behind the test window to be masked with
black. This can aid black accuracy when measuring CRT displays or
projectors.
-n: When
running on a UNIX based system that used the X11
Windowing
System, dispread normally selects the override redirect so that
the
test window will appear above any other windows on the display. On some
systems
this can interfere with window manager operation, and the -n
option
turns this behaviour off.
The -K option
runs through the black and sensor
relative
calibration routines for the Xrite DTP92 and DTP94 instrument, the
black level calibration for the Eye-One Display 1, and a CRT frequency
calibration for the Eye-One Display 2. For the
black calibration the instrument should be placed on an opaque, black
surface, and any stray light should be avoided by placing something
opaque over the instrument. If a
Spectrolino
is being used, then a white and black calibration will always be
performed before
the instrument can be placed on the display, unless the -N
flag is used. Generally it is not necessary to do a calibration every
time an instrument is used, just now and again. There is no point in
doing a CRT frequency calibration, as this will be done
automatically
at the commencement of patch reading.
The -N flag disables any automatic instrument
calibration (used for the Gretag Spectrolino for instance). This would
be used when the instrument is being used for a series of measurements,
and it is inconvenient to place it on it's calibration tile between
measurements. The instrument should be calibrated at least once for
each measurement session though.
The -H option
turns on high resolution spectral mode, if the instrument supports it.
See Operation of particular instruments
for more details.
The -V option
uses adaptive
emission measurement mode, if the instrument supports it,
such as the Eye-One Pro. This may give better accuracy for low level
measurements, but may be more inconsistent overall due to the varying
integration times. Overall measurement time will probably be longer.
The -C "command" option
allows a method of relaying each test value to some other display than
that on the system running dispread (for instance, a photo frame, PDA
screen etc.), by causing the given command to be invoked to the shell,
with six arguments. The first three arguments are the RGB test color as
integers in the range 0 to 255, the second three parameters are the RGB
test color as floating point numbers in the range 0.0 to 1.0. The
script or utility should relay the given color to the screen in some
manner (e.g. by generating a raster file of the given color and sending
it to the display being profiled), before returning. Note that a test
window will also be created on the system running dispread.
The -M "command" option
allows a method of gathering each test value from some external source,
such as an instrument that is not directly supported by Argyll. The
given command is involked to the shell,
with six arguments. The first three arguments are the RGB test color as
integers in the range 0 to 255, the second three parameters are the RGB
test color as floating point numbers in the range 0.0 to 1.0. The
script or utility should create a file called "command.meas" that contains the XYZ
values for the given RGB (or measured from the test window) in cd/m^2
as three numbers separated by spaces, before returning. If the command
returns a non-zero return value,
dispread will abort. Note that a test
window will also be created on the system running dispread.
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 final parameter on the command line is the base
filename for the .ti1
input file, and the .ti3 output
file. dispread will add the .ti1 and .ti3 extensions
automatically.
NOTE that on an X11 system, if
the environment variable ARGYLL_IGNORE_XRANDR1_2
is set (ie. set it to "yes"), then the presence of the XRandR 1.2
extension will be ignored, and other extensions such as Xinerama and
XF86VidMode extension will be used. This may be a way to work around
buggy XRandR 1.2 implementations.
If a large number of patches is being read, the screensaver on many
systems can interfere with the operation of dispread. It is therefore
advisable
in these cases to manually turn off the screensaver before commencing
the
measurements.
If communications break down with a USB connected instrument, you may
have to unplug it, and plug it in again to recover.
Some systems (Apple OSX in particular) have a special set of user
interface controls ("Universal Access") that allows altering the
display in ways designed to assist visually impaired users, by
increasing contrast etc. This will interfere badly with any attempts to
calibrate or profile such a system, and must be turned off in order to
do so. Note that certain magic
keyboard sequences can turn this on by accident.