Iliah's colorimetric densities may work for Normand.
Otherwise, Normand may need "ISO Status" densities, along the lines of
reflection "densitometers"? In such case, Normand will need spectral data
(reflectance values).
/ Roger
-----Original Message-----
From: argyllcms-bounce@xxxxxxxxxxxxx <argyllcms-bounce@xxxxxxxxxxxxx> On
Behalf Of Iliah Borg
Sent: Sunday, January 12, 2020 11:48 AM
To: argyllcms@xxxxxxxxxxxxx
Subject: [argyllcms] Re: spotread
Are you looking for these?
Y/Ywhite = 10^-D
D = log10(Ywhite/Y)
On Jan 11, 2020, at 9:16 PM, Brown, James William wrote:
In a previous email I was trying to use chartread but I now think spotreadis more appropriate.
value of %Reflectance.
I have read a 10-step target with the following values.
Result is XYZ: 88.589951 92.284256 75.495405, D50 Lab: 96.936379
-0.713697 0.538958 Result is XYZ: 76.341950 79.881033 66.063419, D50
Lab: 91.631455 -1.368469 -0.158627 Result is XYZ: 57.279109 59.837903
50.099307, D50 Lab: 81.750003 -1.016969 -0.836566 Result is XYZ:
42.619616 44.417210 37.347080, D50 Lab: 72.506483 -0.617372 -0.975367
Result is XYZ: 29.469258 30.859874 25.531908, D50 Lab: 62.389165
-1.085745 -0.133362 Result is XYZ: 20.185150 21.047218 17.720048, D50
Lab: 53.001133 -0.531669 -0.812328 Result is XYZ: 12.398663 12.970320
10.733602, D50 Lab: 42.718490 -0.726310 -0.108117 Result is XYZ:
7.139078 7.530363 6.128490, D50 Lab: 32.985021 -1.186517 0.379436
Result is XYZ: 2.711866 2.817359 2.173525, D50 Lab: 19.297074
-0.086656 1.343337 Result is XYZ: 0.291114 0.308121 0.238760, D50 Lab:
2.783247 -0.241378 0.290949
I am trying to get to reflection density. The formula I have depends on a
Is there a formula to get to %R from any of the values read by spotread?
Thank you,
Jim
