[argyllcms] Re: eye-one pro Rev A/Rev D IR calibration?
- From: Gerhard Fuernkranz <nospam456@xxxxxx>
- To: argyllcms@xxxxxxxxxxxxx
- Date: Sun, 27 Jun 2010 02:09:50 +0200
Am 26.06.2010 17:53, schrieb Gerhard Fuernkranz:
> I'm not sure though, whether Graeme does some kind of shrinkage in his
> driver, which may lead to the observed bias.
Klaus, in i1pro_compute_white_cal() I find
/* For each wavelength */
for (j = 0; j < m->nwav1; j++) {
if (white_read1[j] < 1000.0)
cal_factor1[j] = white_ref1[j]/1000.0;
else
cal_factor1[j] =
white_ref1[j]/white_read1[j];
}
and
/* For each wavelength */
for (j = 0; j < m->nwav2; j++) {
if (white_read2[j] < 1000.0)
cal_factor2[j] = white_ref2[j]/1000.0;
else
cal_factor2[j] =
white_ref2[j]/white_read2[j];
}
If the white readings happen to be < 1000 at particular wavelenghts,
then a minimum value of 1000 is still enforced for the denominator,
which I assume will lead to a downwards shrinkage/biasing of the
readings at these wawevelengths. It should be easy, to print out the
write_ref1[] and white_ref2[] numbers in order to verify whether or not
they happen to be < 1000 your case.
Regards,
Gerhard
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