XnView MP 64bit with TWAIN 32bit support

[Tim]

<Moderator's note: Originally this was a bug report but it turned out to be a suggestion.>
___

Subject: 0.82 Win: No scan source available

Hi,

in Xnview MP 0.82 there is no scan source available, i have a Canon 9000F M2, in xnview classic the scanner works fine (there are two scan-sorces, Canon 9000 and WIA-Canon 9000), in XnView MP there is nothing to choose from ...

Thank you

[cday]

In XnView MP 0.82 there is no scan source available, I have a Canon 9000F M2, in XnView Classic the scanner works fine (there are two scan-sources, Canon 9000 and WIA-Canon 9000), in XnView MP there is nothing to choose from ...

In XnView MP x64 scanning using the TWAIN interface normally isn't available due to a lack of support in Windows (which can be overcome using a third-party utility) and also lack of support by most scanner manufacturers. Note that scanner manufacturers' x64 bit software normally actually interfaces using the Windows x32 bit TWAIN interface. That's about right, isn't it XnTriq?

I'm not sure why you are unable to scan using the Windows WIA interface, I would have thought that should be possible...

You should, however, be able to scan from XnView MP using TWAIN by installing in XnView MP x32, and there is no reason why both versions can't be installed at the same time, so that should provide a reasonable work-around. The scanner manufacturer's x64 bit software should still be installed. To view PDF files in XnView MP x32 you will, however, need to install Ghostscript x32 which can be similarly be installed in parallel with Ghostcript x64.

[XnTriq]

in Xnview MP 0.82 there is no scan source available, i have a Canon 9000F M2, in xnview classic the scanner works fine (there are two scan-sorces, Canon 9000 and WIA-Canon 9000), in xnview MP there is nothing to choose from ...

Could you please try to run XnView MP as administrator?

In XnView MP x64 scanning using the TWAIN interface normally isn't available due to a lack of support in Windows (which can be overcome using a third-party utility) and also lack of support by most scanner manufacturers. Note that scanner manufacturers' x64 bit software normally actually interfaces using the Windows x32 bit TWAIN interface. That's about right, isn't it XnTriq?

It's my understanding that version 2 of the TWAIN Data Source Manager comes with a fully native 64-bit implementation.

The reason your scanner is missing when you compile as a x64 bit application is that your scanner doesn't have a 64-bit TWAIN driver. Yes, it supports your 64-bit operating system, but it is still only a 32-bit driver and 32-bit implementation of TWAIN. In order to show up to TWAIN in a 64-bit application it needs to implement the full 64-bit TWAIN interface. This limitation is not unique to us, all products that use TWAIN have this same exact limitation.

Googling 'Windows 64 TWAIN' there is clearly a widespread problem using scanners over a TWAIN interface in 64-bit versions of Windows.

The following text from this link may possibly shed some light on the issue:

http://altoimaging.typepad.com/alto-ima ... -meet.html

To our knowledge (based on examining a fairly large number of popular scanners), there are no 64-Bit TWAIN drivers available. They are all running in 32-Bit compatibility mode on 64-Bit PCs. This means that the 32-Bit versions of the apps can use the 32-Bit TWAIN drivers and access a scanner as it would in the 32-Bit OS. But, the 64-Bit versions of the apps cannot access the 32-Bit drivers.

Some scanner suppliers are apparently advertising drivers as 32/64-Bit compatible. This could mean that they are packaging both versions in the driver install file. But, please be aware that in most cases we have seen, it only means that the drivers will work in both 32-Bit and 64-Bit versions of Windows. As discussed above, you can use the 32-Bit drivers in 64-Bit Windows, but only with 32-Bit applications.

I'm not sure whether the following freeware software might be of any help in overcoming this issue:

http://sourceforge.net/projects/twain-dsm/files/

I read a while back something about scanner manufacturers and Microsoft agreeing not to support TWAIN 64 for some reason, but the present situation seems bizare...

• XnView Forums
  • Twain (Select Twain Source and TWIAN Scan)
  • Missing scanning option
  • Scanner in XnViewMP
  • Acquisition Twain
• TWAIN Forum
  • Is there any 64bit virtual scanner?
  • 64-bit TWAIN only sees 64-bit TWAIN drivers?
  • 64 bits TWAIN scanning application
  • Twain driver on Windows 7 64 bit
  • TWAIN and Windows x64
• Stefan Lindblad
  • Scanning CorelDRAW X6 64 bit a macro from SoftBotz Software Studio (25/Mar/2012)
• Graphics Unleashed
  • CorelDRAW X6, 64-bits, Scanning, Twain Drivers and WIA (26/Mar/2012)
• dosadi
  • TWAIN 64bit/32bit Bridge (now Atalasoft EZTwain)
• ScanWorks
  • TwainImporter
• Terminal Works
  • UniTwain
• TWAIN Working Group
  • TWAIN 2.3 Specification

[cday]

In XnView MP x64 scanning using the TWAIN interface normally isn't available due to a lack of support in Windows (which can be overcome using a third-party utility) and also lack of support by most scanner manufacturers. Note that scanner manufacturers' x64 bit software normally actually interfaces using the Windows x32 bit TWAIN interface. That's about right, isn't it XnTriq?

It's my understanding that version 2 of the TWAIN Data Source Manager comes with a fully native 64-bit implementation.

It is important to distinguish between a TWAIN Data Source Manager .dsm and a TWAIN Data Source .ds .

A TWAIN Data Source Manager .dsm provides a means to select one or other TWAIN interface when more than one is available, as when more than one scanner (or other TWAIN device) is installed on the computer. A TWAIN Data Source .ds is the software interface to a particular TWAIN device that is normally provided by the scanner or other device manufacturer.

The reason that TWAIN scanning is normally not available from Windows x64 bit software such as XnView MP is that scanner manufacturers for one reason or another normally don't provide the required 64-bit Data Source .ds . It has been suggested that this is due to the complexity of the feature-rich TWAIN interface and the fact that existing 32-bit Data Sources can be reused on 64-bit Windows in the manufacturer's own software with a suitable software interface to TWAIN 32-bit.

The simple way to scan using TWAIN on 64-bit Windows is to install XnView MP 32-bit, which if desired can be installed alongside XnView MP 64-bit, or alternatively to use XnView Classic for scanning.

That's my current understanding...

[XnTriq]

It is important to distinguish between a TWAIN Data Source Manager .dsm and a TWAIN Data Source .ds.

I was referring to your comment “that scanner manufacturers' x64 bit software normally actually interfaces using the Windows x32 bit TWAIN interface.”
Data Source and Data Source Manager and Application all have to be 64-bit.

• 

64bit TWAIN Applications only work with the 64bit DSM and the 64bit DSM only sees 64bit Data Sources.

1. TWAIN_32.DLL - 32-bit TWAIN device manager compatible with TWAIN 1.x specification.
   This device manager allows to work only with 32-bit TWAIN 1.x and WIA drivers.
   Normally TWAIN_32.DLL is located in "C:\Windows\" directory and included in distributive package of all versions of Windows.
2. TWAINDSM.DLL and TWAINDSM32.MSM - 32-bit TWAIN device manager compatible with TWAIN 2.x specification.
   This device manager allows to work only with 32-bit TWAIN 1.x and 2.x drivers.
   Files of this device manager are NOT included in distributive package of Windows. On 32-bit systems the TWAIN device manager files must be placed in "C:\Windows\System32\" directory. On 64-bit systems the TWAIN device manager files must be placed in "C:\Windows\SysWow64\" directory.
   Latest version of this device manager can be found here:
   http://www.twain.org or http://sourceforge.net/projects/twain-dsm/files/.
3. TWAINDSM.DLL and TWAINDSM64.MSM - 64-bit TWAIN device manager compatible with TWAIN 2.x specification.
   This device manager allows to work only with 64-bit TWAIN 2.x drivers.
   Files of this device manager are NOT included in distributive package of Windows. On 64-bit systems the TWAIN device manager files must be placed in "C:\Windows\System32\" directory.
   Latest version of this device manager can be found here: http://www.twain.org or http://sourceforge.net/projects/twain-dsm/files/.

Unfortunately, there is no TWAIN device manager that can work with 32-bit and 64-bit drivers at the same time and you must choose between 32-bit and 64-bit drivers. We recommend to use 32-bit drivers because most of scanners does not have 64-bit drivers.

[cday]

Isn't the bottom line that scanner manufacturers rarely provide a 64-bit Data Source .ds , so it isn't normally possible to scan from 64-bit software such as XnView MP 64-bit using a TWAIN interface... The practical solution on 64-bit Windows is to use a 32-bit software application such as XnView MP 32-bit or XnView Classic for scanning.

Regarding manufacturers' own 64-bit software which provides scanning on 64-bit Windows, yes, I may have made an incorrect inference that it utilises the Windows 32-bit TWAIN interface, as the interface is really provided to enable scanner access from other software applications.

[XnTriq]

Isn't the bottom line that scanner manufacturers rarely provide a 64-bit Data Source .ds , so it isn't normally possible to scan from 64-bit software such as XnView MP 64-bit using a TWAIN interface... The practical solution on 64-bit Windows is to use a 32-bit software application such as XnView MP 32-bit or XnView Classic for scanning.

Yes, I absolutely agree on all of these points

[Marsu42]

Isn't the bottom line that scanner manufacturers rarely provide a 64-bit Data Source .ds , so it isn't normally possible to scan from 64-bit software such as XnView MP 64-bit using a TWAIN interface... The practical solution on 64-bit Windows is to use a 32-bit software application such as XnView MP 32-bit or XnView Classic for scanning.

Well, in fairness we have to say that scanning with a 32bit twain probably isn't really inferior to 64bit twain :-p ... unless you're using a x64-only windows w/o 32bit subsystem, which might become a reality sooner or later and makes us all buy new scanners.

For 64bit apps, one possible solution could be to write a 32bit exe stub that just runs the twain interface, and then returns the location of the scanned image to the 64bit host app?

[xnview]

For 64bit apps, one possible solution could be to write a 32bit exe stub that just runs the twain interface, and then returns the location of the scanned image to the 64bit host app?

yes i need to write a 32bits stub

[XnTriq]

yes i need to write a 32bits stub

So that stub would act as a “bridge” like EZTwain Classic (public domain)?

[xnview]

yes i need to write a 32bits stub

So that stub would act as a “bridge” like EZTwain Classic (public domain)?

will be in next version

[xnview]

This problem is supposed to be fixed in XnView MP 0.85 beta 1. Please check and confirm the bug fix here.

[cday]

Not working yet:

In Browser | File > Select TWAIN source...

Expected result: Available TWAIN source(s) displayed

Actual result: Nothing...

Windows 7 64-bit on two computers with scanners installed.

[xnview]

Not working yet:

There is an error in the package, please move twain32.exe in Addon folder

[cday]

There is an error in the package, please move twain32.exe in Addon folder

Fixed by moving twain.exe to the AddOn folder.