profile/verify
Summary
Verify a color transform by comparing CIE measurement values from two
test charts. The charts will usually be in .ti3
format, but only XYZ, Lab or spectral values will be used. The overall
average and worst case delta E will be reported, as well as the worst
10% and best 90% of values.
Usage Summary
verify [-options]
target.ti3 measured.ti3
-v
Verbose - print each patch value
-n
Normalise each files reading to white Y
-N
Normalise each files reading to white XYZ
-c
Show CIE94 delta E values
-k
Show CIEDE2000 delta E values
-s
Sort patch value by error
-w
create VRML vector visualisation (measured.wrl)
-w
create VRML marker & vector visualisation
(measured.wrl)
-x
Use VRML axes
-i
illum Choose
illuminant for print/transparency spectral data:
A, D50 (def.), D65, F5, F8, F10 or
file.sp
-o observ
Choose CIE
Observer
for spectral data:
1931_2 (def.), 1964_10, S&B
1955_2, shaw, J&V 1978_2
-f
Use Fluorescent Whitening Agent
compensation
target.ti3 Target
or reference patch data file
measured.ti3 Measured or actual
patch
data file
Usage Details and Discussion
verify provides a way of verifying how well a color
transformation (such a proofing) performs.
The -v flag prints out extra information during the checking,
and prints each patch value, rather than just a summary.
The -n flag causes the two sets of values to be normalized to
the Y value of white for each set before comparison. White is assumed
to be the patch with the largest Y value.
The -N flag causes the two sets of values to be normalized to
the XYZ of white for each set before comparison. White is assumed to be
the patch
with the largest Y value.
The -c option causes the differences between the test values
and
the profile prediction of the color for each device value to be
displayed
in CIE94 delta E, rather than plain L*a*b* delta E. CIE94 delta E has a
closer
correspondence with perceived color differences than the default CIE76
delta E values.
The -k option causes the differences between the test values
and
the profile prediction of the color for each device value to be
displayed
in CIEDE2000 delta E, rather than plain L*a*b* delta E. CIEDE2000 delta
E has a
closer
correspondence with perceived color differences than either CIE76 or
CIE94 delta E values.
If the -s flag is used in combination with the -v
flag,
then the test point by test point output will be sorted from worst to
best.
The -w creates a VRML 3D
visualization
of the differences between the test points in D50 L*a*b* space, each
difference being shown as a line vector. If the -W flag is used, then the target and
measured values will also be marked by a small sphere. This can be used
to visualize the placement of values in a .ti3 (or other CGATS file) by
using the same file for both "target" and "measured" values.
The -x flag adds Lab axes to the VRML output.
The -i flag allows specifying a standard or custom illumination
spectrum, applied to the spectral test point values, to compute CIE
tristimulus
values. A, D50, D65, F5, F8, F10
are a selection of standard illuminant spectrums, with D50
being the
default. If a filename is specified instead, it will be assumed to be
an
Argyll specific .sp spectrum file.
The -o flag allows specifying a tristimulus
observer, and is used to compute PCS (Profile Connection Space)
tristimulus values. 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 same parameter value should be used as was used during the creation
of the profile.
The -f flag enables Fluorescent Whitening Agent compensation,
which compensates for the effect a different illuminant will have, on
any Fluorescent Whitening Agent present in the reflective media.
Spectral patch information is needed for this to function.
If both CIE and spectral values are present in the input files, the CIE
values will be used by default. Using the -i, -o
or -f flag will force spectral
values to be used. The the -i,
-o or -f flags will apply to both the
target and measured input files.