[sane-devel] Epson Perfection 1250/Photo 64-bit

Charles Lindsey chl at clerew.man.ac.uk
Mon Oct 19 13:00:03 BST 2020

On 17/10/2020 22:57, Ralph Little wrote:

> On 2020-10-17 12:37 p.m., Charles Lindsey wrote:

>> Simple-scan runs a calibration (both Course and Fine) om every startup.
>> Xsane has a setting "calibration cache" which can be set in the
>> Standard Options window, and which I had set (because it seemed like a
>> good idea). When set, it causes the result of the calibration to be
>> set in
>>   ~/.sane/Epson_Perfection_1250_Photo-coarse.cal
>> and in
>>   ~/.sane/Epson_Perfection_1250_Photo-fine.cal
>> If it sees these in a later run, it uses them and omits the
>> calibration process entirely. In the backend code there ia a variable
>> 'dev->adj.cacheCalData' but nowhere could I find where it gets set,
>> though I see now it can be set in /etc /sand.d/plustek.conf, which is
>> presumably where simple-scan picks it up.

> Regarding the original problem in the cached files, it seems to me that
> it might be worthwhile version stamping these files so that we can
> change their format and flush out buggy ones with a version bump.

I think it would be more useful to ensure they did not hang around too long. I 
suspect that the calibration of a particular scanner could drift over time, and 
hence any cache over a week old should be ignored anyway.
> Something to consider in future I guess.
> Cheers,
> Ralph

Charles H. Lindsey ---------At my New Home, still doing my own thing------
Tel: +44 161 488 1845                    Web: http://www.cs.man.ac.uk/~chl
Email: chl at clerew.man.ac.uk              Snail-mail: Apt 40, SK8 5BF, U.K.
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