Option for double sided scan via ADF to turn sheet back

Sorry, this should be feature request :)
is it possible to move it there?

Ticket moved from /p/gscan2pdf/bugs/365/

So you mean scan the documents again and throw away the scans?

Can't you do the second run through after saving the first, and then quit without saving the second run?

I don't understand exactly, how it goes, are there special commands for scanner to scan a page side, or not? I thought, it could go so: first side, second side, than again first side without saving and than let out the sheet.

I can, but it means another one scan cycle, where I should lay sheets into scanner again and start the process again.

Aha. You want the "first side again" part to be automatic.

The duplex logic is provided exclusively by the backend. gscan2pdf can only set the options and tell it to scan. Perhaps you could ask Canon to add this feature to the Canon SANE backend?

In the past, I don't think the Canon drivers were open source, so I don't think we can change anything without Canon's help.

I recommend you try gscan2pdf's Preference option "Ignore duplex capabilities of scanner"? You may find this is a faster and more reliable way to scan stacks of pages. Some scanners, like my HP8250, take a lot of time to flip pages one at a time, plus there is increased risk of paper jams. The same is true for many inexpensive all-in-one printer scanners.

With this option, it forces the scanner to scan in single side mode. You scan the first side of your paper stack (sides 1,3,5) , then flip the stack and scan the reverse sides (6,4,2). Gscan2pdf will automatically insert the reverse side images into the list of already=scanned images in the proper order. Your stack of originals always physically remains in the proper order.

Brian