From 3db384424bd7398ffbb7a355cab8f15f3add009f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=B6rg=20Frings-F=C3=BCrst?= Date: Sun, 2 Oct 2016 19:24:58 +0200 Subject: New upstream version 1.9.1+repack --- doc/i1proDriver.html | 346 ++++++++++++++++++++++++++++----------------------- 1 file changed, 192 insertions(+), 154 deletions(-) (limited to 'doc/i1proDriver.html') diff --git a/doc/i1proDriver.html b/doc/i1proDriver.html index 0894f59..e29d639 100644 --- a/doc/i1proDriver.html +++ b/doc/i1proDriver.html @@ -1,157 +1,195 @@ - - The i1pro Driver - - - - -

How can I -have confidence in the i1pro Driver ?
-

-A question that has been asked is : "You've -written your own driver for the Eye-One Pro. How can I have confidence -that the measurements are accurate, and will match those made with the -original manufacturers driver ?"
-
-This is a quite reasonable question. The following attempts to answer -it.
-

Why does Argyll use it's own -i1pro driver ?

-Primarily because the Original Manufacturers Driver (OMD) isn't -available for all the platforms that ArgyllCMS supports (Linux in -particular). A side benefit is that it's possible to tweak many of the -driver parameters for slightly better results and more flexibility. It -has also helped in understanding the characteristics and limitations of -such instruments.
-

Does it match the OMD ?

-In principle the behaviour should be very similar. While the Argyll -driver has been written from scratch, it does use exactly the same -calibration values from
-inside the instrument, and attempts to use the calibration values and -process the raw instrument readings in an equivalent manner to that of -the OMD.
-
-But the proof of the pudding is in the measuring, so to actually verify -this, the following experiment was conducted:
-
-The Argyll version used was V1.2.0
-
-The Macbeth 24 patch ColorChecker was used as a sample target. For each -patch (and the calibration tile), the following steps were performed:
-
-1) Place the instrument on the calibration tile.
-
-2) Use Argyll spotread to calibrate the Argyll driver.
-
-3) Change drivers to the OMD.
-
-4) Use the OMD to calibrate the instrument.
-
-5) Move the instrument to the patch on the ColorChecker.
-
-6) Read the color using the OMD.
-
-7) Change the back to the Argyll driver.
-
-8) Using the calibration made in step 2), read the color using Argyll.
-
-Each calibration or reading was performed 15 seconds from the previous -one, to put the instrument lamp in a repeatable state.
-The instrument was kept in exactly the same position for calibration -and patch measurement with the two drivers.
-(The whole idea is to reduce all other sources of error, other than the -driver itself.)
-
-This measurement was repeated just once for each patch + the -calibration tile. This was done in one run, and the readings were not -specially selected.
-

Results:

-The following D50 L*a*b* values were recorded for each measurement:
-
-A)    The OMD internally calculated L*a*b* value
-B)    The L*a*b* value calculated by Argyll from the OMD -spectral values.
-C)    The L*a*b* value calculated from the Argyll measured -spectral values.
-D)    The L*a*b* value calculated from the Argyll -Hi-Resolution mode measured spectral values.
-
-A is compare to B, to check -that the spectral to standard observer calculations are equivalent.
-
-    The result was an average Delta E (CIE76) of 0.006, -with a maximum of 0.012.
-
-    This shows that there is very close agreement in the -way spectral values are converted to XYZ and L*a*b*.
-
-B is compared to C to check -that the Argyll driver behaves the same as the OMD.
-
-    The result was an average Delta E (CIE76) of 0.028, -with a maximum of 0.051.
-
-    This shows that the OMD and Argyll driver are in -close agreement in spectral measurement.
-    This error is an order of magnitude smaller than -uniformity induced errors typical in the media being measured.
-
-A is compared to C to check -that the Argyll driver and spectral to XYZ differences don't compound.
-
-    The result was an average -Delta E (CIE76) of 0.026, with -a maximum of 0.048.
-
-    Rather than compounding, any spectral to XYZ -differences tend to cancel -out slightly. This is the bottom line -experimental difference between -the two drivers. The actual underlying difference may in fact be less -than this, but it would be necessary to do multiple test runs to -filter out experimental error.
-
-C is compare to D to check -that the Argyll Hi-Resolution mode is behaving reasonably.
-
-    The result was an average Delta E (CIE76) of 0.158, -with a maximum of 0.353.
-
-    Because the ColorChecker samples have relatively -smooth reflectance spectra, it can be expected that
-    the normal and Hi-Res mode results should be fairly -similar. And indeed, this is the case. The biggest
-    differences are for patches -with the largest spectral transitions in them, which is to be expected -as the
-    Hi-Res measurement more -closely follows the spectral shape, while the differences for -spectrally flat
-    patches is neglegable, since both can follow the -spectral shape well.
-
-Example Yellow-Green Patch, Hi-Res & Normal spectrum:
-Yellow-Green patch, Hi-Res vs. Normal
-
-

Conclusions:

-The experimental average difference of 0.026 -Delta E76 shown above provides evidence that despite using a completely -different instrument driver to that supplied with the instrument, the -ArgyllCMS Eye-One pro measurement values have comparable accuracy, and -can be relied upon to match measurements made using the original -manufactures driver.
-

Raw Data:

-The raw data is available in this spread -sheet.
-
-
-
-
-
-
- + + The i1pro Driver + + + + +

How can I + have confidence in the i1pro Driver ?
+

+ A question that has been asked is : "You've + written your own driver for the Eye-One Pro. How can I have + confidence + that the measurements are accurate, and will match those made with + the + original manufacturers driver ?"
+
+ This is a quite reasonable question. The following attempts to + answer + it.
+

Why does Argyll use it's own + i1pro driver ?

+ Primarily because the Original Manufacturers Driver (OMD) isn't + available for all the platforms that ArgyllCMS supports (Linux in + particular). A side benefit is that it's possible to tweak many of + the + driver parameters for slightly better results and more flexibility. + It + has also helped in understanding the characteristics and limitations + of + such instruments.
+

Does it match the OMD ?

+ In principle the behaviour should be very similar. While the Argyll + driver has been written from scratch, it does use exactly the same + calibration values from
+ inside the instrument, and attempts to use the calibration values + and + process the raw instrument readings in an equivalent manner to that + of + the OMD.
+
+ But the proof of the pudding is in the measuring, so to actually + verify + this, the following experiment was conducted:
+
+ The Argyll version used was V1.2.0
+ The OMD is the original version prior to the introduction of the + i1pro2, and hence reporting the native instrument measurements, + rather than applying a conversion to the XRGA standard
+
+ The Macbeth 24 patch ColorChecker was used as a sample target. For + each + patch (and the calibration tile), the following steps were + performed:
+
+ 1) Place the instrument on the calibration tile.
+
+ 2) Use Argyll spotread to calibrate the Argyll driver.
+
+ 3) Change drivers to the OMD.
+
+ 4) Use the OMD to calibrate the instrument.
+
+ 5) Move the instrument to the patch on the ColorChecker.
+
+ 6) Read the color using the OMD.
+
+ 7) Change the back to the Argyll driver.
+
+ 8) Using the calibration made in step 2), read the color using + Argyll.
+
+ Each calibration or reading was performed 15 seconds from the + previous + one, to put the instrument lamp in a repeatable state.
+ The instrument was kept in exactly the same position for calibration + and patch measurement with the two drivers.
+ (The whole idea is to reduce all other sources of error, other than + the + driver itself.)
+
+ This measurement was repeated just once for each patch + the + calibration tile. This was done in one run, and the readings were + not + specially selected.
+

Results:

+ The following D50 L*a*b* values were recorded for each measurement:
+
+ A)    The OMD internally calculated L*a*b* value
+ B)    The L*a*b* value calculated by Argyll from the OMD + spectral values.
+ C)    The L*a*b* value calculated from the Argyll measured + spectral values.
+ D)    The L*a*b* value calculated from the Argyll + Hi-Resolution mode measured spectral values.
+
+ A is compare to B, to + check + that the spectral to standard observer calculations are + equivalent.
+
+     The result was an average Delta E (CIE76) of + 0.006, + with a maximum of 0.012.
+
+     This shows that there is very close agreement in + the + way spectral values are converted to XYZ and L*a*b*.
+
+ B is compared to C to + check + that the Argyll driver behaves the same as the OMD.
+
+     The result was an average Delta E (CIE76) of + 0.028, + with a maximum of 0.051.
+
+     This shows that the OMD and Argyll driver are in + close agreement in spectral measurement.
+     This error is an order of magnitude smaller than + uniformity induced errors typical in the media being measured.
+
+ A is compared to C to + check + that the Argyll driver and spectral to XYZ differences don't + compound.
+
+     The result was an average + Delta E (CIE76) of 0.026, + with + a maximum of 0.048.
+
+     Rather than compounding, any spectral to XYZ + differences tend to cancel + out slightly. This is the bottom + line + experimental difference between + the two drivers. The actual underlying difference may in fact be + less + than this, but it would be necessary to do multiple test runs to + filter out experimental error.
+
+ C is compare to D to check + that the Argyll Hi-Resolution mode is behaving reasonably.
+
+     The result was an average Delta E (CIE76) of + 0.158, + with a maximum of 0.353.
+
+     Because the ColorChecker samples have relatively + smooth reflectance spectra, it can be expected that
+     the normal and Hi-Res mode results should be + fairly + similar. And indeed, this is the case. The biggest
+     differences are for patches + with the largest spectral transitions in them, which is to be + expected + as the
+     Hi-Res measurement more + closely follows the spectral shape, while the differences for + spectrally flat
+     patches is neglegable, since both can follow the + spectral shape well.
+
+ Example Yellow-Green Patch, Hi-Res & Normal spectrum:
+ Yellow-Green patch, + Hi-Res vs. Normal
+
+

Conclusions:

+ The experimental average difference of 0.026 + Delta E76 shown above provides evidence that despite using a + completely + different instrument driver to that supplied with the instrument, + the + ArgyllCMS Eye-One pro measurement values have comparable accuracy, + and + can be relied upon to match measurements made using the original + manufactures driver.
+

Raw Data:

+ The raw data is available in this spread + sheet.
+
+
+
+
+
+
+ -- cgit v1.2.3