[sane-devel] PlusTek Canon Lide configuration and scanimage questions

Gerhard Jaeger gerhard at gjaeger.de
Sun Aug 11 11:48:47 UTC 2013


sorry for the late response.

On Monday 29 July 2013 09:26:12 coxster dillon wrote:
> I am trying to stop my Canon lide 30 which is recognised as a plustek canon scanner from 
> invoking it's course calibration so it performs a scan without checking the bicolour strip 
> everytime from shell using frontend scanimage.

That's why there's a feature/option called cacheCalData. By activating it once, the scanner
does the calibration once and then uses the data instead of doing the calibration each time,

> I have used the -A option and see a few parameters I can set from shell but I have found
> that I can only do this via a change to the plustek configuration file, option:
> option skipCalibration = 1  (installed default 0)
> Then from shell if I want a calibration I specify --calibrate for a fine calibration (I think).

--calibrate does all the steps.

> 1. I need root access to change the plustek configuration file.  Is there a way to pass 
> this option from shell?  I am using the default scanimage frontend.  Perhaps another frontend? 
> I'm a total newbie here.

xsane allows to set and preserve the settings done once. But all those settings are available
via scanimage as well. 

> 2. Also when I change this option, it'll do a scan at 300dpi fine but at 50dpi makes some 
> strange noises and the motor does not move the head forward.  It seems more like a position issue 
> as it trys to move the head back a few mm before scanning when option set to disable calibration. 
> Default settings, it scans at 50dpi fine as the head seems to start a slightly different position.

Strange, but seems to be a bug.

> 3. What are the side affects of not calibrating since I tried it a few times and the images 
> look crisp and clear?

Normally you won't get a "crisp and clear" image. I guess this is because you've already done
the calibration and it has been stored in your home directory. Check ~/.sane directory for *.cal
files. Remove those and scan with calibration set to off. I bet that the images won't look that

> 4. I have used the calibration-cache command.  Turning it on and adding the calibrate switch 
> for first scan and then missing the calibration switch off, obviously with the configuration
> file changes mentioned above.  To my understanding, it does the scan with calibration because 
> of switch and then all other scans while scanner powered and configured will be using a 
> cached version of the calibration data?  I just want to confirm my understand is correct or 
> am I wasting my time here and should not bother with any calibration since all other 
> scans will use some default data?

You should always set the calibration cache command to on, so you make sure that this
feature is used always. I've currently not the sources available, but as mentioned above,
it could be that the calibration data is used if it is found.


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