<!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;"> -v 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;"> -p Use separation profile</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> -l Output Lab rather than XYZ<br> <br style="font-family: monospace;"> </span><span style="font-family: monospace;"> -0 pow Apply power to input device chanel 0-9 (after sep.)<br> <br style="font-family: monospace;"> </span><span style="font-family: monospace;"> -r level Add average random deviation of <level>% to input device values (after sep.)</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> -R level Add average random deviation of <level>% to output PCS values<br> </span></small><small><span style="font-family: monospace;"> -u 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;"> -b L,a,b Scale black point to target Lab value</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> [<span style="font-style: italic;">separation.icm</span>] Device link separation profile</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> </span><i style="font-family: monospace;">profile.</i><span style="font-family: monospace;">[icm|mpp|ti3] </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 </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;"> <span style="font-family: monospace;"></span><i style="font-family: monospace;">inoutfile</i><span style="font-family: monospace;"> 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 -> CMYK, or perhaps CMYK->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>