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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
  <title>fakeread</title>
  <meta http-equiv="content-type"
 content="text/html; charset=ISO-8859-1">
  <meta name="author" content="Graeme Gill">
</head>
<body>
<h2><b>spectro/synthread</b></h2>
<h3>Summary</h3>
Simulate the measurement of a devices response using a synthetic device
model. This is intended for testing of profile creation accuracy. A
device link
separation or color space conversion can be applied before the
print/measure simulation.<br>
<h3>Usage</h3>
<small><span style="font-family: monospace;">synthread [-v] </span></small><small><span
 style="font-family: monospace;">[<span style="font-style: italic;">separation.ic<span
 style="font-family: monospace;">m</span></span>]</span></small><small><span
 style="font-family: monospace;"></span><span
 style="font-family: monospace;"> </span><i
 style="font-family: monospace;">inoutfile</i><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;-v&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; Verbose mode</span><span
 style="font-family: monospace;"></span><span
 style="font-family: monospace;"></span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;-p&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Use separation profile</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;-l&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Output Lab rather than XYZ<br>
<br style="font-family: monospace;">
</span><span style="font-family: monospace;">&nbsp;-0
pow&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Apply power to input device chanel 0-9 (after sep.)<br>
<br style="font-family: monospace;">
</span><span style="font-family: monospace;">&nbsp;-r
level&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Add average random deviation of &lt;level&gt;% to input device values
(after sep.)</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;-R
level&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Add average random deviation of &lt;level&gt;% to output PCS values<br>
</span></small><small><span style="font-family: monospace;">&nbsp;-u
&nbsp; &nbsp; &nbsp;
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Make random deviations have uniform distributions rather than normal</span></small><br
 style="font-family: monospace;">
<small><span style="font-family: monospace;"></span><span
 style="font-family: monospace;">&nbsp;-b
L,a,b&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Scale black point to target Lab value</span><br
 style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;[<span
 style="font-style: italic;">separation.icm</span>]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
Device link separation profile</span><br style="font-family: monospace;">
<span style="font-family: monospace;">&nbsp;</span><i
 style="font-family: monospace;">profile.</i><span
 style="font-family: monospace;">[icm|mpp|ti3] &nbsp; &nbsp; </span><a
 style="font-family: monospace;" href="File_Formats.html#ICC">ICC</a><span
 style="font-family: monospace;">, </span><a
 style="font-family: monospace;" href="File_Formats.html#MPP">MPP</a><span
 style="font-family: monospace;">
or&nbsp;</span><a style="font-family: monospace;"
 href="File_Formats.html#.ti3">.ti3</a><span
 style="font-family: monospace;">
profile/file to use</span><br style="font-family: monospace;">
&nbsp;
<span style="font-family: monospace;"></span><i
 style="font-family: monospace;">inoutfile</i><span
 style="font-family: monospace;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
&nbsp; &nbsp; &nbsp; &nbsp; Base name for
input[</span><a style="font-family: monospace;"
 href="File_Formats.html#.ti1">.ti1</a><span
 style="font-family: monospace;">]/output[</span><a
 style="font-family: monospace;" href="File_Formats.html#.ti3">.ti3</a><span
 style="font-family: monospace;">] file</span></small><br>
<b><br>
Examples</b><br>
<br>
synthread xxxx testvalues<br>
synthread -p xxx separation.icm testvalues<br>
<h3>Comments<br>
</h3>
The <span style="font-weight: bold;">-v</span> flag does nothing at
the moment.<br>
The <span style="font-weight: bold;">-p</span> flag enables a device
to device value conversion before
converting to expected PCS values.<br>
The <span style="font-weight: bold;">-l</span> flag causes the CIE
output values to be L*a*b* rather than the
default XYZ values.<br>
<br>
The <span style="font-weight: bold;">-0, -1, -2 .. -9</span>
parameters are a way of simulating changes in the
behaviour of the simulated printing system. The parameter supplied to
the flag will be used to modify the device values (after any separation
is applied) by raising them to the power of the parameter. This applies
a transfer curve to the simulated device response.<br>
<br>
The <span style="font-weight: bold;">-r</span> parameter is a way of
simulating instability in the behaviour of
the simulated
printing system. The parameter supplied to the flag will be used to
scale a random offset added to the device values (after any separation
is applied). The offset will be a normally distributed error with an
average deviation of level%. A typically value supplied
might be 1.0 to simulate 1% randomness.<br>
<br>
The <span style="font-weight: bold;">-R</span> parameter is a way of
simulating instability in the behaviour of
the simulated
measuring system. The parameter supplied to the flag will be used to
scale a random offset added to the PCS values. The offset will be a
normally distributed error with an average deviation of level%. A
typically value supplied
might be 1.0 to simulate 1% randomness. <br>
<br>
The <span style="font-weight: bold;">-u</span> flag changes the
distribution of the random offsets applied using the <span
 style="font-weight: bold;">-r</span> or <span
 style="font-weight: bold;">-R</span> flags, from the default standard
deviation, to a uniform deviation distribution. The level is still
specified as an average deviation.<br>
<br>
The <span style="font-weight: bold;">-b</span> parameter is a way of
simulating devices that have a different black point to the profile
used. This only works if an ICC profile is used, and scales the black
point to the parameter value. This will be done in XYZ space by
default, and in L*a*b* space if the <span style="font-weight: bold;">-l</span>
flag is used.<br>
<br>
synthread is useful in creating artificial test value for testing <a
 href="colprof.html">colprof</a>, as well as providing one path for
turning an MPP profile into an ICC profile. If a <a
 href="File_Formats.html#.ti3">.ti3</a> file is
specified instead of an <a href="File_Formats.html#ICC">ICC</a> or <a
 href="File_Formats.html#MPP">MPP</a> profile,
then the closest matching measured points in the .<a
 href="File_Formats.html#.ti3">.ti3</a> are substituted
for the test values in the <a href="File_Formats.html#.ti1">.ti1</a>
file on
output. If the <a href="File_Formats.html#.ti1">.ti1</a>
file is a monochrome test file with a White device value, then an RGB <a
 href="File_Formats.html#ICC">ICC</a> profile, <a
 href="File_Formats.html#MPP">MPP</a> or <a
 href="File_Formats.html#.ti3">.ti3</a> may be used, and the White
values will be translated to equal RGB values. If the <a
 href="File_Formats.html#.ti1">.ti1</a>
file is a monochrome test file with a Black device value, then a CMYK <a
 href="File_Formats.html#ICC">ICC</a> profile, <a
 href="File_Formats.html#MPP">MPP</a> or <a
 href="File_Formats.html#.ti3">.ti3</a> may be used, and the Black
values will be translated to equal CMY = 0, K = grey values. <br>
<br>
If a separation device profile is provided (e.g. from CMY -&gt; CMYK,
or perhaps CMYK-&gt;CMYK, to simulate a color correction step before
"printing"), then this will be applied to the .ti1 device values,
before converting the the device values into .ti3 PCS values.<br>
<br>
<br>
<br>
</body>
</html>