diff options
Diffstat (limited to 'doc/illumread.html')
| -rw-r--r-- | doc/illumread.html | 548 |
1 files changed, 293 insertions, 255 deletions
diff --git a/doc/illumread.html b/doc/illumread.html index 0dcf5bd..9b65b2f 100644 --- a/doc/illumread.html +++ b/doc/illumread.html @@ -1,271 +1,309 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> -<html> - <head> - <title>illumread</title> - <meta http-equiv="content-type" content="text/html; - charset=ISO-8859-1"> - <meta name="author" content="Graeme Gill"> - </head> - <body> - <h2><b>spectro/illumread</b></h2> - <h3>Summary</h3> - Use an instrument or instruments to measure an illuminant spectrum, - including estimate its Ultra Violet content. A combination of direct - illumination readings and readings from a piece of paper having some - FWA content are used for this. (If the UV content is not needed, or - a suitable instrument is not available, then <a - href="spotread.html">spotread</a> should be used instead.)<br> - <h3>Usage Summary</h3> - <small><span style="font-family: monospace;">illumread [-options] - illuminant.sp</span><br style="font-family: monospace;"> - <span style="font-family: monospace;"> </span><a - style="font-family: monospace;" href="#v">-v</a><span +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<html>
+ <head>
+ <title>illumread</title>
+ <meta http-equiv="content-type" content="text/html;
+ charset=windows-1252">
+ <meta name="author" content="Graeme Gill">
+ </head>
+ <body>
+ <h2><b>spectro/illumread</b></h2>
+ <h3>Summary</h3>
+ Use an instrument or instruments to measure an illuminant spectrum,
+ including estimate its Ultra Violet content. A combination of direct
+ illumination readings and readings from a piece of paper having some
+ FWA content are used for this. (If the UV content is not needed, or
+ a suitable instrument is not available, then <a
+ href="spotread.html">spotread</a> should be used instead.)<br>
+ <h3>Usage Summary</h3>
+ <small><span style="font-family: monospace;">illumread [-options]
+ illuminant.sp</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><span style="font-family: - monospace;"></span></small><small><span style="font-family: - monospace;"></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 readings 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 + + +
+ Verbose mode</span><span style="font-family:
+ monospace;"></span></small><small><span style="font-family:
+ monospace;"></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 readings 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;"></span><span - style="font-family: monospace;"></span></small><small><span - style="font-family: monospace;"></span></small><font size="-1"><span - style="font-family: monospace;"></span></font><font size="-1"><span - style="font-family: monospace;"><br> - </span></font><font size="-1"><span style="font-family: + + +
+ COM port, 1..4 (default 1)</span><span style="font-family:
+ monospace;"></span><span style="font-family: monospace;"></span><span
+ style="font-family: monospace;"></span></small><small><span
+ style="font-family: monospace;"></span></small><font size="-1"><span
+ style="font-family: monospace;"></span></font><font size="-1"><span
+ style="font-family: monospace;"><br>
+ </span></font><font size="-1"><span style="font-family:
monospace;"> <a href="#N">-N</a> Disable - initial calibration of instrument</span></font> if possible<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> + + +
+ initial calibration of instrument</span></font> if possible<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>
<font size="-1"> <a href="#Yr">-Y r</a> - Set refresh measurement mode</font><br> - </span></font><font size="-1"><span style="font-family: + + +
+ Set refresh measurement mode</font><br>
+ </span></font><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 + + +
+ 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="#T">-T</a><span
+ style="font-family: monospace;">
+ + +
+ Test mode - restore & save measurements to<br>
+ +
+ *_i.sp, *_r.sp, *_p.sp, *_mpir.sp, *_cpir.sp files<br>
+ </span></small> <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="#file"><span style="font-style: italic;">illuminant.sp</span></a> File - to save measurement to<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>illumread</b> uses a suitable instrument to read an illuminant - spectrum, and uses an indirect method to estimate the Ultra Violet - content of the illuminant, so as to provide better accuracy with <a - href="FWA.html">FWA compensation</a>. An instrument or combination - of instruments capable of spectral measurement of both emissive - measurement and reflective measurement without a U.V. filter is - required for this.<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 plotting of the - spectral reflectance/transmittance values. You must select the plot - window and strike a key in it 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 initial 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;">illumread</span> so as to display the - usage information (i.e. "illumread -?" or "illumread --"), 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="N"></a><span style="font-weight: bold;">-N</span> Any - instrument that requires regular calibration will ask for - calibration on initial start-up. Sometimes this can be awkward if - the instrument is being mounted in some sort of measuring jig, or - annoying if several sets of readings are being taken in quick - succession. The -<span style="font-weight: bold;">N</span> - suppresses this initial calibration if a valid and not timed out - previous calibration is recorded in the instrument or on the host - computer. It is advisable to only use this option on the second and - subsequent measurements in a single session.<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="Yr"></a> The -<span style="font-weight: bold;">Y r</span> - option turns on refresh mode measurement, if the instrument supports - it. This may improve the repeatability of measurements of - illuminants that have a repetitive flicker.<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="file"></a>The <span style="font-weight: bold; font-style: - italic;">illuminant.sp</span> is the name of the file to save the - resulting illuminant spectrum to. The format used is <a - href="File_Formats.html#.sp">.sp</a>.<br> - <br> - <hr style="width: 100%; height: 2px;"><br> - Unlike the other measurement utilities, <span style="font-weight: - bold;">illumread</span> doesn't connect to the instrument until it - is about to make a measurement. This allows for the possibility of - using a different instrument for each measurement.<br> - <br> - It will display a menu:<br> - <br> - Press 1 .. 6<br> - 1) Measure direct illuminant<br> - 2) Measure illuminant reflected from paper<br> - 3) Measure paper<br> - 4) Select another instrument, Currently 1 'usb:/bus4/dev2/ - (GretagMacbeth i1 Pro)'<br> - 5) Compute illuminant spectrum, average result with 0 previous - readings & save it<br> - 6) Compute illuminant spectrum from this reading & save result<br> - 7) Exit<br> - <br> - There are three measurements to be made, after which the illuminant - can be computed and saved. Before each measurement, the instrument - may need calibrating.<br> - <br> - The first measurement needs a spectral instrument capable of reading - in an ambient or emissive mode. For instance, a Spectrolino, Eye-One - Pro or ColorMunki would be suitable instruments.<br> - <br> - The second measurement needs a spectral instrument capable of - reading in an projector or emissive mode. For instance, a - Spectrolino, Eye-One Pro or ColorMunki would be suitable - instruments.<br> - <br> - The third measurement needs a spectral instrument capable of reading - in reflective mode with UV included. For instance, a Spectrolino, - Eye-One Pro, DTP20, DTP22 or DTP41 would be suitable - instruments, as long as they are not fitted with UV filters.<br> - <br> - To be able to estimate the level of Ultra Violet (UV) light in the - illuminant, a reasonable sized piece of white paper needs to be - used. The paper should have some noticeable level of FWA - (Fluorescent Whitener Additive, or Optical Brightening Agents) in - it, so that it responds to UV light. A piece of cheap copier paper - is ideal, since cheap paper is typically whitened with large amounts - of FWA. If the paper is thin (less than 160 gsm) then two or three - sheets should be used to prevent any background showing through. [If - the intention is to use the illuminant spectrum for proofing to a - particular paper, then an alternative might be to use a piece of the - intended paper for this purpose. It's unclear which may give a - better result.]<br> - <br> - The first measurement <span style="font-weight: bold;">1)</span>, - is to use either the ambient or emissive measurement mode to measure - the illumination directly.<br> - <br> - <div style="margin-left: 40px;">If the instrument supports an - ambient measurement capability, then it will be used. If the - insrument does not have an ambient mode, then an emissive - measurement mode can be used, although typically many illuminants - are too bright to directly point the instrument at. A work-around - is to reflect the illuminant from a spectrally flat white surface. - A good candidate for this is a piece of white, fine textured - polystyrene foam. [The suitability of a reflector can be checked - using <span style="font-weight: bold;">spotread -S</span> to - check that the reflection characteristic is close to flat.]<br> - <br> - <img style="width: 228px; height: 300px;" alt="Measuring Ambient" - src="illumread_1.jpg"><img style="width: 141px; height: 282px;" - alt="Measuring Ambient" src="illumread_2.jpg"> <img - style="width: 226px; height: 282px;" alt="Measuring Ambient" - src="illumread_3.jpg"><br> - </div> - <br> - The second measurement <span style="font-weight: bold;">2)</span>, - is to measure the illuminant after it has reflected from the paper.<br> - <br> - <div style="margin-left: 40px;">This is done by placing the paper - such that it is uniformly illuminated with reasonable brightness, - and then placing the instrument so that it receives the reflected - light from the paper. This is typically achieved by placing the - instrument close to the paper at about 45º, so that it's - aperture has a clear view of the illuminated paper, but avoiding - shadowing the region that is in view. <br> - <br> - <img style="width: 219px; height: 261px;" alt="Measuring via - Paper" src="illumread_5.jpg"><img style="width: 252px; height: - 259px;" alt="Measuring via Paper" src="illumread_4.jpg"><br> - </div> - <br> - The third measurement <span style="font-weight: bold;">3)</span>, - is to measure the paper directly using the instrument reflective - mode measurement.<br> - <div style="margin-left: 40px;"><img style="width: 186px; height: - 162px;" alt="Measuring Paper" src="illumread_6.jpg"><br> - </div> - If a different instrument is needed, use <span style="font-weight: - bold;">4)</span> to select from the available instruments attached - to your computer.<br> - <br> - Once these three measurements have been made, then the illuminant - readings spectrum can be computed and save using <span - style="font-weight: bold;">6)</span>, or a series of readings can - be made with each reading being averages with the previous readings - before saving it by using <span style="font-weight: bold;">5)</span>. - Note that the averaged readings will be weighted by their absolute - intensities, and that while the direct and indirect illumination - needs measuring for each reading, the same paper measurement can be - used each time.<br> - <br> - If plotting is enabled, a plot of the measured (black) and with - estimated UV (red) is plotted. This is followed by a plot showing - measured paper reflectance (black) and the FWA calculated paper - reflectance (red).<br> - <br> - <br> - Illumread can then be terminated using <span style="font-weight: - bold;">7)</span>.<br> - <br> - <br> - <br> - <br> - <br> - <br> - <br> - <br> - <br> - <br> - <br> - </body> -</html> + + +
+ to save measurement to<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>illumread</b> uses a suitable instrument to read an illuminant
+ spectrum, and uses an indirect method to estimate the Ultra Violet
+ content of the illuminant, so as to provide better accuracy with <a
+ href="FWA.html">FWA compensation</a>. An instrument or combination
+ of instruments capable of spectral measurement of both emissive
+ measurement and reflective measurement without a U.V. filter is
+ required for this.<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 plotting of the
+ spectral reflectance/transmittance values. You must select the plot
+ window and strike a key in it 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 initial 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;">illumread</span> so as to display the
+ usage information (i.e. "illumread -?" or "illumread --"), 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="N"></a><span style="font-weight: bold;">-N</span> Any
+ instrument that requires regular calibration will ask for
+ calibration on initial start-up. Sometimes this can be awkward if
+ the instrument is being mounted in some sort of measuring jig, or
+ annoying if several sets of readings are being taken in quick
+ succession. The -<span style="font-weight: bold;">N</span>
+ suppresses this initial calibration if a valid and not timed out
+ previous calibration is recorded in the instrument or on the host
+ computer. It is advisable to only use this option on the second and
+ subsequent measurements in a single session.<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="Yr"></a> The -<span style="font-weight: bold;">Y r</span>
+ option turns on refresh mode measurement, if the instrument supports
+ it. This may improve the repeatability of measurements of
+ illuminants that have a repetitive flicker.<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="T"></a>The <b>-T</b> flag invokes the test mode. In test
+ mode the three measurements are saved to files <i>illuminant</i><i>_i.sp</i>
+ (Illuminant spectrum), <i>illuminant</i><i>_r.sp</i> (Illuminant
+ off paper spectrum), and <i>illuminant_p.sp (</i>Instrument
+ measured paper reflectance spectrum), and these will be loaded if
+ discovered, allowing a replay of the calculation without requiring
+ any measurement. In addition, two diagnostic files <i>illuminant</i><i>_mpir.sp</i>
+ (Measured paper under illuminant spectrum) and <i>illuminant</i><i>_cpir.sp +
+ (</i>Computed paper under illuminant spectrum) will be saved.<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="file"></a>The <span style="font-weight: bold; font-style:
+ italic;">illuminant.sp</span> is the name of the file to save the
+ resulting illuminant spectrum to. The format used is <a
+ href="File_Formats.html#.sp">.sp</a>.<br>
+ <br>
+ <hr style="width: 100%; height: 2px;"><br>
+ Unlike the other measurement utilities, <span style="font-weight:
+ bold;">illumread</span> doesn't connect to the instrument until it
+ is about to make a measurement. This allows for the possibility of
+ using a different instrument for each measurement.<br>
+ <br>
+ It will display a menu:<br>
+ <br>
+ Press 1 .. 6<br>
+ 1) Measure direct illuminant<br>
+ 2) Measure illuminant reflected from paper<br>
+ 3) Measure paper<br>
+ 4) Select another instrument, Currently 1 'usb:/bus4/dev2/
+ (GretagMacbeth i1 Pro)'<br>
+ 5) Compute illuminant spectrum, average result with 0 previous
+ readings & save it<br>
+ 6) Compute illuminant spectrum from this reading & save result<br>
+ 7) Exit<br>
+ <br>
+ There are three measurements to be made, after which the illuminant
+ can be computed and saved. Before each measurement, the instrument
+ may need calibrating.<br>
+ <br>
+ The first measurement needs a spectral instrument capable of reading
+ in an ambient or emissive mode. For instance, a Spectrolino, Eye-One
+ Pro or ColorMunki would be suitable instruments.<br>
+ <br>
+ The second measurement needs a spectral instrument capable of
+ reading in an projector or emissive mode. For instance, a
+ Spectrolino, Eye-One Pro or ColorMunki would be suitable
+ instruments.<br>
+ <br>
+ The third measurement needs a spectral instrument capable of reading
+ in reflective mode with UV included. For instance, a Spectrolino,
+ Eye-One Pro, DTP20, DTP22 or DTP41 would be suitable
+ instruments, as long as they are not fitted with UV filters.<br>
+ <br>
+ To be able to estimate the level of Ultra Violet (UV) light in the
+ illuminant, a reasonable sized piece of white paper needs to be
+ used. The paper should have some noticeable level of FWA
+ (Fluorescent Whitener Additive, or Optical Brightening Agents) in
+ it, so that it responds to UV light. A piece of cheap copier paper
+ is ideal, since cheap paper is typically whitened with large amounts
+ of FWA. If the paper is thin (less than 160 gsm) then two or three
+ sheets should be used to prevent any background showing through. If
+ the intention is to use the illuminant spectrum for proofing to a
+ particular paper, then it's best to use the intended paper for this
+ purpose.<br>
+ <br>
+ The first measurement <span style="font-weight: bold;">1)</span>,
+ is to use either the ambient or emissive measurement mode to measure
+ the illumination directly.<br>
+ <br>
+ <div style="margin-left: 40px;">If the instrument supports an
+ ambient measurement capability, then it will be used. If the
+ insrument does not have an ambient mode, then an emissive
+ measurement mode can be used, although typically many illuminants
+ are too bright to directly point the instrument at. A work-around
+ is to reflect the illuminant from a spectrally flat white surface.
+ A good candidate for this is a piece of white, fine textured
+ polystyrene foam. [The suitability of a reflector can be checked
+ using <span style="font-weight: bold;">spotread -S</span> to
+ check that the reflection characteristic is close to flat.]<br>
+ <br>
+ <img style="width: 228px; height: 300px;" alt="Measuring Ambient"
+ src="illumread_1.jpg"><img style="width: 141px; height: 282px;"
+ alt="Measuring Ambient" src="illumread_2.jpg"> <img
+ style="width: 226px; height: 282px;" alt="Measuring Ambient"
+ src="illumread_3.jpg"><br>
+ </div>
+ <br>
+ The second measurement <span style="font-weight: bold;">2)</span>,
+ is to measure the illuminant after it has reflected from the paper.<br>
+ <br>
+ <div style="margin-left: 40px;">This is done by placing the paper
+ such that it is uniformly illuminated with reasonable brightness,
+ and then placing the instrument so that it receives the reflected
+ light from the paper. This is typically achieved by placing the
+ instrument close to the paper at about 45º, so that it's aperture
+ has a clear view of the illuminated paper, but avoiding shadowing
+ the region that is in view. <br>
+ <br>
+ <img style="width: 219px; height: 261px;" alt="Measuring via
+ Paper" src="illumread_5.jpg"><img style="width: 252px; height:
+ 259px;" alt="Measuring via Paper" src="illumread_4.jpg"><br>
+ </div>
+ <br>
+ The third measurement <span style="font-weight: bold;">3)</span>,
+ is to measure the paper directly using the instrument reflective
+ mode measurement.<br>
+ <div style="margin-left: 40px;"><img style="width: 186px; height:
+ 162px;" alt="Measuring Paper" src="illumread_6.jpg"><br>
+ </div>
+ If a different instrument is needed, use <span style="font-weight:
+ bold;">4)</span> to select from the available instruments attached
+ to your computer.<br>
+ <br>
+ Once these three measurements have been made, then the illuminant
+ readings spectrum can be computed and save using <span
+ style="font-weight: bold;">6)</span>, or a series of readings can
+ be made with each reading being averages with the previous readings
+ before saving it by using <span style="font-weight: bold;">5)</span>.
+ Note that the averaged readings will be weighted by their absolute
+ intensities, and that while the direct and indirect illumination
+ needs measuring for each reading, the same paper measurement can be
+ used each time.<br>
+ <br>
+ If plotting is enabled, a plot of the measured (black) and with
+ estimated UV (red) is plotted. This is followed by a plot showing
+ measured paper reflectance (black) and the FWA calculated paper
+ reflectance (red).<br>
+ <br>
+ <br>
+ Illumread can then be terminated using <span style="font-weight:
+ bold;">7)</span>.<br>
+ <br>
+ <br>
+ <br>
+ <br>
+ <br>
+ <br>
+ <br>
+ <br>
+ <br>
+ <br>
+ <br>
+ </body>
+</html>
|