1. from the frontend perspective, duplex is no different from simplex adf, there are just more images.
2. i have never gotten xsane's multi-page mode to work, i use 'scanimage -b' or 'scanadf' command line tools 3. there are several other backends which support duplex scans. fujitsu, avision, epjitsu come to mind. You could look at their code for suggestions, but then your code becomes a derivative work, and you must release it also under the GPL. 4. The way to write your code depends on the scanner. If the scanner has enough memory to buffer the back side data until after the front-side has been read, then you just read them sequentially. if the scanner sends back the data interlaced, then you must buffer the back side in memory until the front side has been sent to front-end, then read back side from buffer. the fujitsu backend demonstrates both of these. 5. be aware that a proper front-end in batch mode will call sane_start() at the beginning of each page, but only call sane_cancel after the last page returns SANE_STATUS_NO_DOCS. 6. what scanner is this for? it would be nice to know to avoid duplication of effort... allan 2008/3/25 changyun L <eagleskycloud at gmail.com>: > > > Dear all, > > I use xsane 0.995.My scanner supports simplex ADF scan .Does > xsane support duplex ADF scan? If xsane supports duplex scan, how do I > write my scanner backends? > -- > sane-devel mailing list: sane-devel at lists.alioth.debian.org > http://lists.alioth.debian.org/mailman/listinfo/sane-devel > Unsubscribe: Send mail with subject "unsubscribe your_password" > to sane-devel-request at lists.alioth.debian.org > -- "The truth is an offense, but not a sin"
