[sane-devel] ADF scanning

[Henning Meier-Geinitz]

Hi,

On Mon, Oct 17, 2005 at 12:09:41PM -0400, Rayudu Addagarla wrote:
> when one uses adf scanner.
> what does a backend return the each page is done.
> say i use, scanadf -s1 -e3
> 
> After each page is done a backend returns what SANE_STATUS??

IIRC, the frontend just tries to scan (sane_start) and if the backend
returns SANE_STATUS_GOOD, there is still paper in the ADF. If that's
not the case:

> i know that at the end backend should return SANE_STATUS_NO_DOCS

> how will scanadf know that each page scanning is done and again continue fot
> the next untill NO_DOCS.

Once sane_read() returns SANE_STATUS_EOF the frontend should call
sane_cancel(). If the frontend likes, it can start an new scan with
sane_start().

> Is there any detailed document for writing a backed for ADF scanner

I don't know of anything special, only the SANE standard.

Bye,
  Henning