> > Devices are not really linear. There are a number of 'distortions'.
One is
> > offset, the second is linearity, and the third is gain.
> I think Austin was refering to the analogue pre-amplifiers built into a
lot of A/D
> converters.
You are correct, but I was not limiting the source of the distortion to
anything in particular. These distortions can be corrected in the digital
or the analog domain. I prefer the digital domain. Gain and offset can be
corrected for by simple multiplication and addition (you do need to do the
gain multiply first), but linearity requires a LUT.
> I think the difficulty is in predicting or calculating the exact value of
any offset.
> Since it'll vary with individual CCD, and with temperature.
Calibration can be as simple or as difficult as the designer wants to make
it, but it certainly can be done.
