Using the LEADTOOLS THUNK Utility with TWAIN

The LEADTOOLS TWAIN Thunk Utility was created to enable you to interact with Win32 TWAIN drivers from a 64-bit process. For instance, a Scanner driver that is ONLY supported on a 32-bit environment will not be able to interact with a scanner from a 64-bit process application. The LEADTOOLS TWAIN Thunk Utility will help you to do so.

The LEADTOOLS THUNK Utility with TWAIN includes the following components:

• THUNK utility 32-bit DLL
• THUNK utility 64-bit DLL
• THUNK server, based on ATL technology.

Distributed files are:

• ltthunkserver.exe (this must be registered)
• ltthunkutlu.dll
• Ltthunkutlx.dll (used only in 64-bit environment)
• lttwnthunku.dll
• Lttwnu.dll
• Ltkrnu.dll
• Ltfilu.dll
• Lfbmpu.dll
• Lfcmpu.dll
• Lfrawu.dll
• Lftifu.dll

To register the THUNK utility:

• Go to the Windows Command prompt.

• Type the following line:

                        C:\LEADTOOLS 20\Bin\Common\LEADTOOLS Thunk\ltthunkserver.exe" /regserver 

To use the THUNK utility, call L_TwainInitSession2 and pass LTWAIN_INIT_USE_THUNKSERVER to the uFlags parameter. The only time the THUNK server should be used is when using a TWAIN device that does not have a 64-bit driver and a 64-bit operating system is being used to run the application.