[sane-devel] correcting upside-down pages in duplex mode using ADF

[m. allan noah]

"they all do that" is specific to these HP all-in-ones. Other scanners
fix this in hardware or in the driver software. Does their TWAIN
driver do this on windows?

Not everyone uses xsane- what about scanimage or gscan2pdf. They would
also have to implement this flipping code. Hence, this is a problem
with the hplip sane backend, for which the source should be available.
That is the place the fix should be made.

allan

On Fri, Jan 30, 2015 at 11:52 AM, ken <gebser at mousecar.com> wrote:
> Thanks, Allan.  I talked with HP tech support about this too and the answer
> I got was, "they all do that" and, if you want that kind of scanning (where
> all the pages come out right-side-up), you have to get a dedicated scanner
> which costs twice as much (and doesn't have printing and faxing
> capabilities).
>
> My current office space isn't large enough to accommodate a lot of such
> dedicated devices and, for other reasons, a less expensive all-in-one (AIO)
> printer like the one I bought makes sense.  I mean, for $150 I get a nice
> ADF/duplex printer, scanner, copier, and fax machine; that's a lot of
> technology in a relatively small space and for a very good price.  That they
> provide drivers for Linux is also major.
>
> Yes, it would be much better if HP designed into this product the logic
> which would do "convert -flip" in the hardware.  It would be much faster if
> done in the hardware and probably cost them just a couple bucks more per
> machine.  But that's the economic system we have and it's not likely to
> change in the near future.  I just thought that, if "they all do that
> [backside upside-down thing]", there might be an option in xsane-- say, a
> button in the GUI to click on-- to vertically flip the backside of each page
> when scanning in duplex mode.  Maybe the option would best reside in xsane's
> configuration settings for the individual scanner. (?)
>
> Would this list be the place to make this feature request?
>
>
>
> On 01/30/2015 08:11 AM, m. allan noah wrote:
>>
>> I hate to sound like a broken record :) I don't think there is a
>> setting to fix this in xsane, because this is a bug in the backend.
>> IMHO, the individual backend is responsible for making the image make
>> sense.
>>
>> In the short term, you should be able to use 'convert -rotate 180' to
>> rotate those images.
>>
>> allan
>>
>> On Fri, Jan 30, 2015 at 5:38 AM, ken <gebser at mousecar.com> wrote:
>>>
>>> When scanning several pages using the ADF in duplex mode, the backside of
>>> each page is rendered upside-down.  Is there some setting in xsane to
>>> flip
>>> the backside of each page vertically so that it's right-side-up?
>>>
>>> Failing that, is there a utility to accomplish the same thing
>>> programmatically after the fact?
>>>
>>> Thanks for all good tips.
>>>
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>>
>>
>>
>>
>



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