[sane-devel] Making neutral scans

[Grant]

>>>>> Not at all. I've seen two different units of the same scanner give
>>>>> very different tone scans with the same options set. You need a
>>>>> reference target to scan.
>>>>>
>>>>> allan
>>>>
>>>> But color management can be used after the fact, right?  I'd like to
>>>> have a reference copy of everything I scan that I can apply things
>>>> like color management or unsharp mask to later on.
>>>
>>> Yes- if the colors are reasonable, a profile specific to that machine
>>> could be used to clean it further
>>>
>>> allan
>>
>> So if I make sure my gamma correction is always at 1.8 and I always
>> leave all the sliders alone, I should be able to produce consistent
>> reference scans that I can apply the same set of adjustments (ICC
>> profile, maybe others) to later on to produce something as accurate as
>> possible?
>>
>> I just want to make sure I'm not forgetting anything.
>
> In theory, yes. But software upgrades might change a calibration algo,
> and the sensors and lamp will drift over time, and the temperature in
> the room will change, which might cause small changes. The only proper
> way to get true stability is to run a color target periodically, and
> rebuild your profile. That implies that you should be applying the
> profile as you scan, or storing the scan of the color target serially
> with your normal scans for later processing.

Storing the scan of the color target as I scan is an interesting idea.
 Could the same thing be done with a "white marks" target to later
move pixels to eliminate artifacts?

- Grant