The -D parameter modifies the colorspace set by -d by allowing individual
colorants to be added or subtracted from the colorspace.
(1) how to make -D Working in add mode and Working in Subtracted mode?do the
command is same?
The -e parameter sets the number of white colored test patches, defaulting to 4
if the -e flag isn't used. The white patches are usually very important in
establishing white point that the ICC data is made relative to, so it improves
robustness to use more than a single point.
(2)what do -e do ? I see no difference between setting 2 and 4.
The -B parameter sets the number of black colored test patches, defaulting to 4
if the -B flag isn't used and the colorspace is grey or RGB. The black point
can be very important for characterizing additive color spaces, so measuring
more than one black patch improves robustness over measuring just a single
point.
(3)same as question (2)
The -s parameter sets the number of patches in a set of per colorant wedges.
The steps are evenly spaced in device space by default, and the total number of
test patches will be the number of colorants times the value specified with the
-s flag. If the -p parameter is provided, then, then the steps will be
distributed according to the power value. e.g. the option -s 5 will generate
steps at 0.0 0.25 0.5 0.75 and 1.0, while the option -s 5 -p 2.0 will generate
steps at 0.0 0.0625 0.25 0.5625 and 1.0. By default, no per colorant test wedge
values are generated. When creating a test chart for a device that will be used
as a source colorspace, it is often useful to generated some per colorant wedge
values.
The -g parameter sets the number of patches in a set of combined (nominally
gray) wedges. This will typically be equal RGB or CMY values, and by default
will be equally spaced steps in device space. If the -p parameter is provided,
then, then the steps will be distributed according to the power value. e.g. the
option -g 5 will generate steps at 0.0 0.25 0.5 0.75 and 1.0, while the option
-g 5 -p 2.0 will generate steps at 0.0 0.0625 0.25 0.5625 and 1.0. By default,
no gray combination values are generated. When creating a test chart for a
device that will be used as a source colorspace, it is often useful to
generated some per colorant wedge values.
The -m parameter sets the edge size of the multidimensional grid of test
values. The total number of patches of this type will be the -m parameter value
to the power of the number of colorants. The grid steps are evenly spaced in
device space by default, but if the -p parameter is provided, then, then the
steps will be distributed according to the power value. e.g. the option -m 5
will generate steps at 0.0 0.25 0.5 0.75 and 1.0, while the option -m 5 -p 2.0
will generate steps at 0.0 0.0625 0.25 0.5625 and 1.0. By default, all the
device primary color combinations that fall within the ink limit are generated..
The -b parameter sets the outer edge size of the multidimensional body centered
grid of test values. The total number of patches of this type will be the -b
parameter value to the power of the number of colorants plus the (number-1) to
the power of the number of colorants. The grid steps are evenly spaced in
device space by default, but if the -p parameter is provided, then, then the
steps will be distributed according to the power value. A body centered grid is
a regular grid (see -m) with another smaller regular grid within it, at the
centers of the outer grid. This grid arrangement is more space efficient than a
regular grid (ie. for a given number of test points, it fills the space better.)
??4??what do -s -g -m -b do? and what's the difference between those
parameters? And what's the math algorithm behind the step
And the parameter: 0.0 0.25 0.5 0.75 and 1.0,
0.0 0.0625 0.25 0.5625 and 1.0.
The behavior of the -e, -s, -g -m and -b flags, is not to duplicate test values
already created by a previous type.
The -f parameter sets the number of full spread test patches. Full spread
patches are distributed according to the default or chosen algorithm. The
default algorithm will optimize the point locations to minimize the distance
from any point in device space, to the nearest sample point. This is called
Optimized Farthest Point Sampling (OFPS) . This can be overridden by specifying
the -t. -r, -R, -q, -i or -I flags. If the default OFPS algorithm is used, then
adaptive test point distribution can be fully enabled by supplying a previous
or typical profile with the -c option. The total number patches specified will
include any patches generated using the -e, -s, -g -m and -b flags (i.e. full
spread patches will be added to bring the total number of patches including
those generated using the -e, -s, -g-m and -b flags up to the specified
number). When there are more than four device channels, the full spread
distribution algorithm can't deal with so many dimensions, and targen falls
back on an incremental far point distribution algorithm by default, that
doesn't generate such evenly spread points. This behaviour can be forced using
the -t flag. A table of useful total patch counts for different paper sizes is
shown below. Note that it's occasionally the case that the OFPS algorithm will
fail to complete, or make very slow progress if the -c profile is poor,
non-smooth, or has unusual behaviour. In these cases a different algorithm
should be chosen (ie. -Q or -I), or perhaps a smoother or lower resolution
("quality") previous profile may overcome the problem.
The -t flag overrides the default full spread test patch algorithm, and makes
use of the Incremental Far Point Distribution algorithm, which incrementally
searches for test points that are as far away as possible from any existing
points. This is used as the default for dimensions higher than 4.
The -r flag overrides the default full spread test patch algorithm, and chooses
test points with an even random distribution in device space.
The -R flag overrides the default full spread test patch algorithm, and chooses
test points with an even random distribution in perceptual space.
The -q flag overrides the default full spread test patch algorithm, and chooses
test points with a quasi-random, space filling distribution in device space.
The -Q flag overrides the default full spread test patch algorithm, and chooses
test points with a quasi-random, space filling distribution in perceptual space.
The -i flag overrides the default full spread test patch algorithm, and chooses
test points with body centered cubic distribution in device space.
The -I flag overrides the default full spread test patch algorithm, and chooses
test points with body centered cubic distribution in perceptual space.
The -a angle parameter sets the overall angle that the body centered grid
distribution has.
??5??what is the parameters function and what will they do to the OFPS
algorithm?
BTW:i am a chinese user with poor english unstanding so please help me with
patience thx a lot ! :)
