<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>spotread</title> <meta http-equiv="content-type" content="text/html; charset=ISO-8859-1"> <meta name="author" content="Graeme Gill"> </head> <body> <h2><b>spectro/spotread</b></h2> <h3>Summary</h3> Use an instrument to read a single color value. This can be a useful diagnostic aid. The type of instrument is determined by the communication port selected. <h3>Usage Summary</h3> <small><span style="font-family: monospace;">spotread [-options] [logfile]</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#v">-v</a><span style="font-family: monospace;"> Verbose mode</span><br style="font-family: monospace;"> <span style="font-family: monospace;"></span><span style="font-family: monospace;"> </span></small><small><span style="font-family: monospace;"></span><a style=" font-family: monospace;" href="#s">-s</a><span style="font-family: monospace;"> Print spectrum for each reading.</span></small><br style="font-family: monospace;"> <small><span style="font-family: monospace;"></span><span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#S">-S</a><span style="font-family: monospace;"> Plot the spectrum in a graph window.</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#c">-c comport</a><span style="font-family: monospace;"> Set COM port, 1..4 (default 1)</span><span style="font-family: monospace;"></span><span style="font-family: monospace;"><br style="font-family: monospace;"> </span><span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#t">-t</a><span style="font-family: monospace;"> Use transmission measurement mode</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#d">-d</a><span style="font-family: monospace;"> Use display measurement mode (absolute results)<br> </span></small><small><span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#db">-db</a><span style="font-family: monospace;"> Use display white brightness relative measurement mode<br> </span></small><small><span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#dw">-dw</a><span style="font-family: monospace;"> Use display white relative measurement mode<br> </span></small><small><span style="font-family: monospace;"> </span><a style=" font-family: monospace;" href="#p">-p</a><span style="font-family: monospace;"> Use projector measurement mode (absolute results)<br> </span></small><small><span style="font-family: monospace;"> </span><a style=" font-family: monospace;" href="#pb">-pb</a><span style="font-family: monospace;"> Use </span></small><small><span style="font-family: monospace;">projector</span></small><small><span style="font-family: monospace;"> white brightness relative measurement mode<br> </span></small><small><span style="font-family: monospace;"> </span><a style=" font-family: monospace;" href="#pw">-pw</a><span style="font-family: monospace;"> Use </span></small><small><span style="font-family: monospace;">projector</span></small><small><span style="font-family: monospace;"> white relative measurement mode</span></small><br> <small><span style="font-family: monospace;"> </span><a style=" font-family: monospace;" href="#e">-e</a><span style="font-family: monospace;"> Use emissive measurement mode (absolute results)</span></small><br> <small><span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#a">-a</a><span style="font-family: monospace;"> Use ambient measurement mode (absolute results)<br> <a href="#f">-f</a> Use ambient flash measurement mode (absolute results)<br> </span></small><font size="-1"><span style="font-family: monospace;"> <a href="#y">-y X</a> Display type - instrument specific list to choose from.</span></font><br style="font-family: monospace;"> <small><span style="font-family: monospace;"></span><span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#i">-i illum</a><span style="font-family: monospace;"> Choose illuminant for print/transparency spectral data:</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> A, D50 (def.), D65, F5, F8, F10 or file.sp</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> </span><a style=" font-family: monospace;" href="#Q">-Q observ</a><span style="font-family: monospace;"> Choose CIE Observer for spectral data or CCSS instrument:</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> </span></small><small><span style="font-family: monospace;">1931_2 </span></small><small><span style="font-family: monospace;"> (def.)</span></small><small><span style="font-family: monospace;">, 1964_10, S&B 1955_2, shaw, J&V 1978_2</span></small><small><span style="font-family: monospace;"></span></small><font size="-1"><span style="font-family: monospace;"><br> <a href="#F">-F filter</a> Set filter configuration:<br> n None<br> p Polarising filter<br> 6 D65<br> u U.V. Cut<br> <a href="#E">-E extrafilterfile</a> Apply extra filter compensation file<br> </span></font><font size="-1"><span style="font-family: monospace;"> <a href="#x">-x</a> Display Yxy instead of Lab<br> </span></font><font size="-1"><span style="font-family: monospace;"> <a href="#h">-h</a> Display LCh instead of Lab</span></font><br> <font size="-1"><span style="font-family: monospace;"> <a href="#V">-V</a> Show running average and std. devation from ref.</span></font><br> <font size="-1"><span style="font-family: monospace;"> <a href="#T">-T</a> Display correlated color temperatures and CRI<br> </span></font><font size="-1"><span style="font-family: monospace;"> <a href="#N">-N</a> Disable auto calibration of instrument</span></font><br> <font size="-1"><span style="font-family: monospace;"> </span><a style="font-family: monospace;" href="#H">-H</a><span style="font-family: monospace;"> Use high resolution spectrum mode (if available)<br> </span></font><font size="-1"><span style="font-family: monospace;"><a href="#X1">-X file.ccmx</a> Apply Colorimeter Correction Matrix</span></font><br> <span style="font-family: monospace;"> <a href="#X2">-X file.ccss</a> Use Colorimeter Calibration Spectral Samples for calibration</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> <a href="#X3">-X N</a> 0: Technology (Display description)</span><br style="font-family: monospace;"> <span style="font-family: monospace;"> 1: etc.</span><br> <font size="-1"><span style="font-family: monospace;"> <a href="#W">-W n|h|x</a> Override serial port flow control: n = none, h = HW, x = Xon/Xoff</span></font><br> <small><span style="font-family: monospace;"> </span><a style=" font-family: monospace;" href="#D">-D [level]</a><span style="font-family: monospace;"> Print debug diagnostics to stderr</span></small><br> <font size="-1"><span style="font-family: monospace;"> <a href="#log"><span style="font-style: italic;">logfile</span></a> Optional file to save reading results<br style="font-family: monospace;"> </span></font><small><span style="font-family: monospace;"></span><span style="font-family: monospace;"></span></small><br> <h3>Usage Details and Discussion</h3> <b>spotread</b> operates in a similar fashion to <a href="chartread.html"> chartread</a>, but allows the reading of a succession of single color values. This can be useful in diagnosing issues with profile creation and operation.<br> <br> <a name="v"></a>The <b>-v</b> flag causes extra information to be printed out during chartread operation.<br> <br> <a name="s"></a>The <b>-s</b> flag enables the printing out spectral reflectance/transmittance values, if the instrument supports this.<br> <br> <a name="S"></a>The <b>-S</b> flag enables the plotting of the spectral reflectance/transmittance values, if the instrument supports this. If a reference is taken, this will be plotted in red. You must strike a key in the plot window to continue with another measurement.<br> <br> <a name="c"></a> The instrument is assumed to communicate through a USB or serial communication port, and the port can be selected with the <b>-c</b> option, if the instrument is not connected to the first port. If you invoke <span style="font-weight: bold;">spotread</span> so as to display the usage information (i.e. "spotread -?" or "spotread --"), 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.<br> <br> <a name="t"></a>If using an Xrite DTP41T or SpectroScanT, and printing onto transparent or back lit media, use the <b>-t</b> flag to operate the instrument in transparency mode. If using the Spectroscan, this triggers a fake transparency mode, that uses a separate backlight (such as a light box). The instrument will be used to calibrate the level of backlight, and use this to compute the transparency of the test chart samples. Note that for good transparency values, the backlight level needs to be neither too bright not too dark, should ideally be incandescent rather than fluorescent (since fluorescent lights often have big dips in their spectrum), and ideally should be of uniform brightness over the measurement area.<br> <br> <a name="d"></a>The <span style="font-weight: bold;">-d</span> flag allows measuring in display mode, using instruments that support this mode. Values returned are absolute.<br> <br> <a name="db"></a>The <span style="font-weight: bold;">-db</span> flag allows measuring in display mode using instruments that support this mode, with the brightness normalized to the white value read as the first reading. While the brightness values are then relative to the white, the readings are otherwise absolute. This corresponds to the raw ICC absolute readings created by <a href="dispread.html">spotread</a>.<br> <br> <a name="dw"></a>The <span style="font-weight: bold;">-dw</span> flag allows measuring in display mode using instruments that support this mode, with the white normalized to the white value read as the first reading.<br> <br> <a name="p"></a>The <span style="font-weight: bold;">-p</span> flag allows measuring in projector mode, using instruments that support this mode. Values returned are absolute.<br> <br> <a name="pb"></a>The <span style="font-weight: bold;">-pb</span> flag allows measuring in projector mode using instruments that support this mode, with the brightness normalized to the white value read as the first reading. While the brightness values are then relative to the white, the readings are otherwise absolute. This corresponds to the raw ICC absolute readings created by <a href="dispread.html">spotread</a>.<br> <br> <a name="pw"></a>The <span style="font-weight: bold;">-pw</span> flag allows measuring in projector mode using instruments that support this mode, with the white normalized to the white value read as the first reading.<br> <br> <a name="e"></a>The <span style="font-weight: bold;">-e</span> flag allows measuring in emission mode (e.g. displays or illuminants) using instruments that support this mode. An adaptive integration time will be used in devices that support it. Values returned are absolute.<br> <br> <a name="a"></a>The <span style="font-weight: bold;">-a</span> flag allows measuring in ambient illumination mode using instruments that support this mode (i.e. Eye-One Display 2). Values returned are absolute, and include the various color temperatures and Color Rendering Index (see <span style="font-weight: bold;">-T</span>). If the instrument does not support ambient mode, emissive mode will be used instead. An adaptive integration time will be used in devices that support it. <br> <br> <a name="f"></a>The <span style="font-weight: bold;">-f</span> flag allows measuring a flash with those instruments that support scanning emissive measurements. The instrument needs to be triggered by holding down its button, triggering the flash, then releasing the button, similar to how a reflective strip is read.<br> <br> <a name="y"></a> The <span style="font-weight: bold;">-y</span> flag allows setting the Display Type. Most colorimeters need this parameter set to operate correctly. The selection typically determines two aspects of of the instrument operation: <span style="font-weight: bold;">1)</span> It may set the measuring mode to suite <a href="http://en.wikipedia.org/wiki/Comparison_of_display_technology"><span style="font-weight: bold;">refresh</span> or <span style="font-weight: bold;">non-refresh</span> displays</a>. Typically only LCD (Liquid Crystal) displays have a non-refresh nature. <span style="font-weight: bold;">2)</span> It may select an instrument calibration matrix suitable for a particular display type. The selections available depends on the type and model of instrument, and a list of the options for the discovered instruments will be shown in the <a href="ArgyllDoc.html#CmdLine">usage</a> information. For more details on what particular instruments support and how this works, see <a href="instruments.html">Operation of particular instruments</a>.<br> <br> <a name="i"></a>The <b>-i</b> flag allows specifying a standard or custom illumination spectrum, applied to <span style="text-decoration: underline;">reflective</span> spectral data to compute CIE tristimulus values. <b>A</b>, <b>D50</b>, <b>D65</b>, <b>F5</b>, <b>F8</b>, <b>F10</b> are a selection of standard illuminant spectrums, with <b>D50</b> being the default. If a filename is specified instead, it will be assumed to be an Argyll specific <a href="File_Formats.html#.sp">.sp</a> spectrum file.<br> <br> <a name="Q"></a> The <b>-Q</b> flag allows specifying a tristimulus observer, and is used to compute PCS (Profile Connection Space) tristimulus values. This is possible for a spectral instrument, or a colorimeter that has CCSS capability. The following choices are available:<br> <b> 1931_2</b> selects the standard CIE 1931 2 degree observer. The default.<br> <b>1964_10</b> selects the standard CIE 1964 10 degree observer.<br> <b>1955_2</b> selects the Stiles and Birch 1955 2 degree observer<br> <b>1978_2 </b>selects the Judd and Voss 1978 2 degree observer<br> <b>shaw</b> selects the Shaw and Fairchild 1997 2 degree observer<br> <br> <a name="F"></a>The <b>-F</b> options allows configuring the instrument to have a particular filter fitted to it. Some instruments (i.e. the Gretag Spectrolino) allow the fitting of various filters, such as a polarizing filter, D65 illuminant simulation, or Ultra Violet Cut filter, and this option allows the instrument to be configured appropriately.<br> <br> <a name="E"></a>The <b>-E</b> option allows the setting of an extra filter compensation file, that allows for the filtration of the spectral readings through a medium of some kind, when in emission mode. This is useful in allowing for such things as telescopic adapters that use a glass of acrylic lens in the optical path. [<span style="font-weight: bold;">Note</span> that this is currently only supported by the Spectrolino driver.]<br> <br> <a name="x"></a>The <b>-x</b> option causes the reading to be displayed as XYZ and Yxy values, rather than the default XYZ and L*a*b*<br> <br> <a name="h"></a>The <b>-h</b> option causes the reading to be displayed as XYZ and LCh values, rather than the default XYZ and L*a*b*<br> <br> <a name="V"></a>The <b>-V</b> enables average and standard deviation statistics on the L*a*b* values. This start and is reset whenever a reference is taken ('r' key). This is useful in quantifying repeatability.<br> <br> <a name="T"></a>The <b>-T</b> option causes various color temperatures to be displayed, plus the Color Rendering Index. Three color temperatures will be shown. The first is the classic Correlated Color Temperature, which is the black body (Plankian) color closest to the measured color in the CIE 1960 UCS color space. The second is the black body (Plankian) color that has a minimum CIEDE2000 error to the measured color. The last is the daylight color that has a minimum CIEDE2000 error to the measured color. The delta E between the closest temperature and the measured color is also shown for each. The Color Rendering Index (CRI Ra) is also computed if the instrument is capable of spectral measurement. If the notation <span style="font-weight: bold;">(Invalid)</span> is displayed after the CRI, then this means that the the spectrum white point is to far from the black body and Daylight locus to be meaningful.<br> <br> <a name="N"></a>The <b>-N</b> option disables the automatic calibration of an instrument if it is possible to do so. Sometimes it is awkward to have to re-calibrate and instrument every time a tool starts, and unnecessary if the instrument has recently been calibration, and this switch prevents it happening.<br> <br> <a name="H"></a> The -<span style="font-weight: bold;">H</span> option turns on high resolution spectral mode, if the instrument supports it. See <a href="instruments.html">Operation of particular instruments</a> for more details.<br> <br> <a name="X1"></a> The -<span style="font-weight: bold;">X <span style="font-style: italic;">file.ccmx</span></span> option reads a <a href="File_Formats.html#.ccmx">Colorimeter Correction Matrix</a> from the given file, and applies it to the colorimeter instruments readings. This can improve a colorimeters accuracy for a particular type of display. A list of contributed <span style="font-weight: bold;">ccmx</span> files is <a href="ccmxs.html">here</a>.<br> <br> <a name="X2"></a> The -<span style="font-weight: bold;">X <span style="font-style: italic;">file.ccss</span></span> option reads a <a href="File_Formats.html#.ccss">Colorimeter Calibration Spectral Sample</a> from the given file, and uses it to set the colorimeter instruments calibration. This will only work with colorimeters that rely on sensor spectral sensitivity calibration information (ie. the X-Rite <span style="font-weight: bold;">i1d3</span>, or the DataColor <span style="font-weight: bold;">Spyder4</span>).This can improve a colorimeters accuracy for a particular type of display.<br> <br> <a name="X3"></a> The -<span style="font-weight: bold;">X <span style="font-style: italic;">N</span></span> option selects a <a href="File_Formats.html#.ccss">Colorimeter Calibration Spectral Sample</a> from the list of installed ccss files, rather than specifying a specific ccss files as in the above usage. The CCSS file that came with the i1d3 colorimeters can be installed using <a href="i1d3ccss.html">i1d3ccss</a>, or one can be created and installed using <a href="ccxxmake.html">ccxxmake</a>.<br> <br> <a name="W"></a>The <b>-W</b> <span style="font-weight: bold;">n|h|x</span> parameter overrides the default serial communications flow control setting. The value <span style="font-weight: bold;">n</span> turns all flow control off, <span style="font-weight: bold;">h</span> sets hardware handshaking, and <span style="font-weight: bold;">x</span> sets Xon/Xoff handshaking. This commend may be useful in workaround serial communications issues with some systems and cables. <br> <br> <a name="D"></a>The <b>-D</b> 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.<br> <br> <a name="log"></a>The <span style="font-weight: bold; font-style: italic;">logfile</span> is an optional file that can be specified to capture each reading taken. There will be column headers printed to the first row, and then each reading will be on a separate line with tab separators.<br> <br> All instruments will be used in a spot mode. For the SpectroScan instrument, the samples can be placed on the table, and the measuring head positioned before taking a measurement. Note that the default mode (reflectance measurement) may not be supported by the instrument, so a mode it does support will be selected automatically. Override this on the command line if desired. Note that the DTP51, DTP92, DTP94 and Eye-One Display are colorimeters, and cannot read spectral information, and that the DTP92 can only read CRT type displays.<br> <br> <hr style="width: 100%; height: 2px;"><br> Once <b>spotread</b> has established communications with the instrument, it awaits a command from the user, indicated by the user hitting a key or activating the instrument switch. XYZ values are in the range 0 .. 100 for reflective or transmissive readings, and absolute cd/m^2 for display, emissive and ambient readings.<br> <br> The L*a*b* values are computed relative to a D50 100 scale white point. (Note that using display white relative mode makes the L*a*b relative to the display white point.)<br> <br> If Fluorescent Whiter Additive (FWA) compensated readings are to be made, then this needs to be enabled with the correct command line switches, and then setup for each paper white background color, to establish an FWA reference. There is one FWA reference locations available for each alphabetic character not used for a special function (ie. not <span style="font-weight: bold;">H, K, N, Q, R, S)</span>, keyed to the capital letters <b>A-</b><b>Z</b>, allowing FWA corrected comparisons between many different media.<br> <br> Once a particular reference location is initialized with the FWA paper color, subsequent readings triggered by using the corresponding lower case letter <span style="font-weight: bold;">a-z</span> will use FWA compensation for that keyed location. Note that readings that are triggered some other way (ie. using a non alphabetic key, or using the instrument switch) will not be FWA corrected readings.<br> <br> If a non-FWA readings is to be performed, then a reading for a location that has not been initialised for paper white should be used, or a non alphabetic key (such as space or return) or instrument switch trigger should be used.<br> <br> If the instrument supports a high resolution spectral mode, then it can be toggled on and off using the <span style="font-weight: bold;">h</span> key.<br> <br> If the instrument supports stored readings (ie. DTP20), then these can be ignored using the <span style="font-weight: bold;">n</span> key.<br> <br> The previous reading can be stored as a reference, and delta E's computed for each reading, using the <b>r</b> key.<br> <br> A previous spectral reading can be saved in a spectrum CGATS file (spectrum.sp) using the <span style="font-weight: bold;">s</span> key, making this a convenient way of creating a custom illuminant spectrum.<br> <br> A calibration can be initiated using the <span style="font-weight: bold;">k</span> key.<br> <br> <br> <br> <br> <br> <br> <br> <br> <br> <br> </body> </html>