From c07d0c2d2f6f7b0eb6e92cc6204bf05037957e82 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Mon, 1 Sep 2014 15:43:52 +0200 Subject: Imported Upstream version 1.6.3 --- doc/illumread.html | 272 ++++++++++++++++++++++------------------------------- 1 file changed, 112 insertions(+), 160 deletions(-) (limited to 'doc/illumread.html') 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 @@

spectro/illumread

Summary

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 spotread should be used - instead.)
+ 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 spotread should be used instead.)

Usage Summary

illumread [-options] illuminant.sp
@@ -26,6 +22,7 @@ style="font-family: monospace;" href="#v">-v                +     Verbose mode
@@ -34,46 +31,46 @@ style="font-family: monospace;" href="#S">-S              -  -     Plot - the readings in a graph window.
+       Plot the readings in a graph window.
 -c comport            Set - COM port, 1..4 - (default 1)
 -N                    Disable + initial calibration of instrument if possible
 -H              -      - Use high resolution spectrum mode (if - available)
+       Use high resolution spectrum mode + (if available)
+  -Y r                  + Set refresh measurement mode
 -W n|h|x              Override + serial port flow control: n = none, h = HW, x = Xon/Xoff
 -D [level]            - Print - debug diagnostics to stderr
-   -
+   illuminant.sp         File + to save measurement to

@@ -81,40 +78,26 @@ File illumread 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 FWA - compensation. 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.
+ href="FWA.html">FWA compensation. 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.

The -v flag causes extra information to be - printed out during - chartread operation.
+ printed out during chartread operation.

The -S 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.
+ spectral reflectance/transmittance values. You must select the plot + window and strike a key in it to continue with another measurement.

The instrument is assumed to communicate through a USB or serial communication port, and the initial port can be - selected - with the - -c - option, - if the instrument is not connected to the first port. If you invoke - illumread - 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 -c option, if the instrument is not + connected to the first port. If you invoke illumread 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.

-N Any @@ -129,40 +112,39 @@ File subsequent measurements in a single session.

The -H - option - turns on high resolution spectral mode, if the instrument supports - it. - See Operation of particular instruments - for more details.
+ option turns on high resolution spectral mode, if the instrument + supports it. See Operation of particular + instruments for more details.
+
+ The -Y r + 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.

The -W n|h|x - parameter overrides the default serial communications - flow control setting. The value n - turns all flow control off, h + parameter overrides the default serial communications flow control + setting. The value n turns + all flow control off, h sets hardware handshaking, and x sets Xon/Xoff handshaking. This commend may be useful in workaround serial communications issues with some systems and cables.

- The -D 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 + The -D 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.
+ tracking down why an instrument can't connect.

The illuminant.sp is - the name of the file to save the resulting illuminant spectrum to. - The - format used is .sp.
+ italic;">illuminant.sp is the name of the file to save the + resulting illuminant spectrum to. The format used is .sp.


Unlike the other measurement utilities, illumread 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.
+ bold;">illumread 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.

It will display a menu:

@@ -173,74 +155,55 @@ File 4) Select another instrument, Currently 1 'usb:/bus4/dev2/ (GretagMacbeth i1 Pro)'
5) Compute illuminant spectrum, average result with 0 previous - readings - & save it
+ readings & save it
6) Compute illuminant spectrum from this reading & save result
7) Exit

There are three measurements to be made, after which the illuminant - can - be computed and saved. Before each measurement, the instrument may - need - calibrating.
+ can be computed and saved. Before each measurement, the instrument + may need calibrating.

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.
+ in an ambient or emissive mode. For instance, a Spectrolino, Eye-One + Pro or ColorMunki would be suitable instruments.

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.
+ reading in an projector or emissive mode. For instance, a + Spectrolino, Eye-One Pro or ColorMunki would be suitable + instruments.

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.
+ 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.

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.]
+ 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.]

The first measurement 1), - is - to use either the ambient or emissive measurement mode to measure - the - illumination directly.
+ is to use either the ambient or emissive measurement mode to measure + the illumination directly.

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 spotread -S - to check that the reflection characteristic is close to flat.]
+ 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 spotread -S to + check that the reflection characteristic is close to flat.]

Measuring Ambient
The second measurement 2), - is - to measure the illuminant after it has reflected from the paper.
+ is to measure the illuminant after it has reflected from the paper.

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.
+ 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.

Measuring via Paper3), - is - to measure the paper directly using the instrument reflective mode - measurement.
+ is to measure the paper directly using the instrument reflective + mode measurement.
Measuring Paper
If a different instrument is needed, use 4) to select from the available - instruments attached to your computer.
+ bold;">4) to select from the available instruments attached + to your computer.

Once these three measurements have been made, then the illuminant - readings spectrum - can be computed and save using 6), - or a series of readings can be made with each reading being averages - with the previous readings before saving it by using 5). 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.
-
- 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).
+ readings spectrum can be computed and save using 6), or a series of readings can + be made with each reading being averages with the previous readings + before saving it by using 5). + 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.
+
+ 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).


Illumread can then be terminated using