[sane-devel] Missing Resolution for Canon MG7550

[Rolf Bensch]

Hi Martin,

Gernot is right. The scanner provides only 75, 150, 300, 600, 1200 and
2400 dpi.

If you need other resolutions, you need to post process your images with
e.g. imagemagick or gimp.

Cheers,
Rolf


Am 18.08.2015 um 17:11 schrieb Gernot Hassenpflug:
> On Tue, Aug 18, 2015 at 9:06 PM, Martin <martin.gu at intergga.ch
> <mailto:martin.gu at intergga.ch>> wrote:
> 
>     Hi Rolf,
> 
>     The sane backend does not provide all resolutions of the scanner:
> 
>     Xsane offers 75, 150, 300, 600, 1200 and 2400 ppi.
> 
>     Canon's scangear however offers 75, 100, 150, 200, 300, 400, 600 and
>     1200 ppi.
> 
> 
> Hello Martin,
> There is infact no such physical resolution as 200 and 400.
> All the physical scans use resolutions which are multiples of 75.
> A 200dpi scan will be done at 300dpi and scangear simply filters it down
> to 200.
> Likewise, 400 is done at 600dpi and filtered down.
> SANE implements the physical scanning capability. Since the 200 and 400
> are done in software, it would be a filter in the front-end, not the
> backend.
> At least, that is my understanding.
> Regards,
> Gernot Hassenpflug