Hi , With your help,I have achieved duplex ADF scan in our backend with sane-backends 1.0.19 and XSane 0.995. Xsane could get front image and back image of a paper at the same time while scanning with ADF.
I save back image in a buffer allocated by my backends then Xsane read a back image after XSane have get a whole front image. Below suggestion is from m. allan noah: 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. ... Thank you. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.alioth.debian.org/pipermail/sane-devel/attachments/20080618/16944bf8/attachment.htm
