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| author | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2014-09-07 13:29:54 +0200 |
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| committer | Jörg Frings-Fürst <debian@jff-webhosting.net> | 2014-09-07 13:29:54 +0200 |
| commit | a879b4e708b3e46c9697ba6581687eeb5b02a320 (patch) | |
| tree | f85acc5cb1a7c0b03a050c879c20cab3deb9f40e /doc/illumread.html | |
| parent | 556dffcdad42b938bc196819aa463247de709765 (diff) | |
| parent | c07d0c2d2f6f7b0eb6e92cc6204bf05037957e82 (diff) | |
state from 2014-09-07 13:30 MESZ
Diffstat (limited to 'doc/illumread.html')
| -rw-r--r-- | doc/illumread.html | 272 |
1 files changed, 112 insertions, 160 deletions
diff --git a/doc/illumread.html b/doc/illumread.html index 03b5648..0dcf5bd 100644 --- a/doc/illumread.html +++ b/doc/illumread.html @@ -10,15 +10,11 @@ <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> + 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;"> @@ -26,6 +22,7 @@ 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;"> @@ -34,46 +31,46 @@ 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;"> + 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 + + 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> + 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: 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 + 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> @@ -81,40 +78,26 @@ File <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> + 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> + 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> + 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 + 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 @@ -129,40 +112,39 @@ File 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> + 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> + 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 + <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> + 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> + 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> + 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> @@ -173,74 +155,55 @@ File 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> + 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> + 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> + 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> + 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> + 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> + 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> + 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> + 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;" @@ -250,22 +213,15 @@ File </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> + 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> + 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: @@ -273,33 +229,29 @@ File </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> + 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> + 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> + 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: |