python-twain library in duplex mode get separate image from each side

Question

I am trying to scan using python-twain library in duplex mode and get two images one from each side.

import twain
sm = twain.SourceManager(0)
ss = sm.OpenSource('Plustek MobileOffice D600')

ss.SetCapability( twain.CAP_DUPLEXENABLED, twain.TWTY_BOOL, True )
ss.RequestAcquire(0,0)
rv = ss.XferImageNatively()
if rv:
    (handle, count) = rv
    twain.DIBToBMFile(handle, 'image.bmp') 

The code only get one image but with the library documentation provided at http://twainmodule.sourceforge.net/ , I don't see how to get take independently images from it. I know is possible because I could get in a demo from a close source library CLScan(http://www.commandlinescanning.com).

Any suggestions will be welcome.

Answer 1

I found the sample code TwainBackend.py on GitHub. You can use a loop to save all available images:

import twain

index = 0;

def next(ss):
    try:
        print ss.GetImageInfo()
        return True
    except:
        return False

def capture(ss):
    global index
    rv = ss.XferImageNatively()
    fileName = str(index) + '_image.bmp';
    index+=1;
    print rv;
    if rv:
        (handle, count) = rv
        twain.DIBToBMFile(handle, fileName) 

sm = twain.SourceManager(0)
ss = sm.OpenSource('Plustek MobileOffice D600')

try:    
    ss.SetCapability( twain.CAP_DUPLEXENABLED, twain.TWTY_BOOL, True)
except:
    print "Could not set duplex to True"

print "acquire image"
ss.RequestAcquire(0,0)

while next(ss):
    capture(ss)

print('Done')