[sane-devel] How to accurately scan A4(210mmx297mm) size paper?

[m. allan noah]

On 6/26/08, eagleskycloud <eagleskycloud at gmail.com> wrote:
>
> Hi,
>
> I want to accurately scan A4 paper(210mmx297mm),but there is not
> A4(210mmx297mm) item in preset area drop down box in preview window of
> XSane.

my version of Xsane (.95) has DIN A3, A4, and A5, both in portrait and
landscape.

 I add 210mmx297mm item in the  preset area drop down box. XSane exit
> and output segmentation fault in console after I select 210mmx297mm  and I
> don't  click the scan button.

chances are your backend did something weird when xsane changed the x
and y params, like some math that produced a negative scan area? put
in some debugging and see if you can reproduce it.

>  The 210mmx297mm item that I just added  has
> not already in the drop down box when I run XSane at the second time.

because it crashed before saving your change.

> I drag
> and adjust the scan size to 210.31mmx297.15mm, then click the scan button
> and the scan is OK . I couldn't  accurately drag and adjust the scan size to
> 210mmx297mm. How to accurately scan A4(210mmx297mm) size?

it may not be possible to set those exact sizes, that depends on your
backend, and the fact that the x and y values are SANE_FIX/SANE_UNFIX,
things always get rounded a little bit, depending on the size of your
'quant'. but some of this might be clunkyness in the xsane interface-
try using a command line front-end like scanimage, and see if you can
set the sizes there.

allan
-- 
"The truth is an offense, but not a sin"