I have a TWAIN scanning program that runs fine in Windows 7 but when used in Windows XP, the scanned images are black. What are the possible reasons that could be the cause of this issue?
I found AllAquire demo that has the ADF. How do you save the image as soon as the scan is complete? There used to be a OnAcquireBitmap event before that I could save the file.
You could try "Multi\MultiView" demo. It acquire using ADF and allows you to save acquired pages. Anyway if you see the image in the preview then the image is acquired (they are not "black").
Can I use the event OnFinishWork to automatically save the file after the image is acquired? Or do I have to resort to using TImageEnIO since it has a OnAcquireBitmap event? If yes, there is no demo that uses a TImageEnIO that I can test.
TwainDemo also has the same problem. Scans fine on first Acquire, but second and subsequent acquires, give black images and sometimes freezes the application. I am using the Plustek scanner in Windows XP.
Please could you try another workstation with the same scanner and a different (newer?) scanner driver version? Have you the same problem with Multi\MultiView demo?
I am also getting memory errors when scanning at 600 dpi repeatedly. It will do it once but a second or more times give a "out of memory" status from the TWAIN. is this an issue with the TWAIN or ImageEn? It also seems to happen only on a Windows XP computer.
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Black scanned images in XP
Posted - Mar 05 2012 : 08:02:02
