[argyllcms] Re: eye-one pro Rev A/Rev D IR calibration?

  • From: Gerhard Fuernkranz <nospam456@xxxxxx>
  • To: argyllcms@xxxxxxxxxxxxx
  • Date: Sun, 27 Jun 2010 11:49:23 +0200

Am 27.06.2010 10:13, schrieb Klaus Karcher:
> I thought I got the trick in i1pro_meas_to_abssens():
> if (rval >= maxpve)
>     rval -= 0x00010000;    /* Convert to -ve */
> but I still get many overflows. (I use the maxpve value returned from
> i1pro_getmisc(): 0xfa00)

Hi Klaus, I must admit that I can't assess this piece of code, since I
don't know how rval is supposed to be encoded. The code suggests that
we're dealing with an asymmetric, signed 16-bit encoding, which can
encode  more positive than negative numbers (given the actual maxvpe
value of 0xfa00). Granted that this assumption is correct, I'm
wondering, though, whether it is really an "overflow" if negative
numbers are returned, or whether these are still valid readings (albeit
negative ones).


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