Using Twain Module in Python

Question

I have 64 bit Windows and 64 bit Python . In the twain docs said : supports only 32 bit . I have used twain data source to install my 64 bit machine and used this code to connect scanner device:

import twain
sm = twain.SourceManager(0)
ss = sm.OpenSource()
ss.RequestAcquire(0,0) 
rv = ss.XferImageNatively()
if rv:
   (handle, count) = rv
twain.DIBToBMFile(handle, 'image.bmp')

When I run the app. a windows opens like :

so why this window is empty . The scanner device will show in this window ?

Answer 1

The driver files for a 32 bit driver will be placed twain_32 folder and 64 bit driver files under the twain_64 folder. The twain DSM which searches for the drivers available has two versions 32 and 64 bit. The 32 bit version of the DSM looks for the drivers in the twain_32 folder and 64 bit version under the 64 bit version of the folder. Hence, it looks like you need to check which version of the driver is installed (32/64 bit). Dependency walker will help you quickly resolve this issue. More details on dependencies - Refer to chapter 12 - https://www.twain.org/wp-content/uploads/2016/03/TWAIN-2.2-Spec.pdf