This topic and its replies were posted before the current version of LEADTOOLS was released and may no longer be applicable.
#1
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Tuesday, April 8, 2008 12:16:21 PM(UTC)
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Hello
How do I detect when the scanner is finished scanning?
Regards,
Simon
#2
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Wednesday, April 9, 2008 12:35:15 AM(UTC)
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Simon,
Can you tell me what version of LEADTOOLS and what LEADTOOLS programming Interface (DLL API, C++ Classes, .NET, etc.) you are using?
Also, what is the function you are using to acquire images?
#3
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Monday, April 14, 2008 11:27:05 AM(UTC)
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#4
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Tuesday, April 15, 2008 6:28:59 AM(UTC)
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You may try to check this using the the AcquirePage event of the TwainSession object, this event Occurs for each page acquired from the currently selected TWAIN source using the Acquire method. When the Twin source finish this event will not fire
#5
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Saturday, September 6, 2008 3:58:04 AM(UTC)
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Hi Adnan -
I have the same question as the OP, however I don't understand your answer. You're suggesting that to detect when scanning is finished, you check for the absence of an event firing? Perhaps I'm being obtuse, but that doesn't make any sense. I would expect an event to fire to indicate that scanning is finished, or a flag on the AcquireAquirePageEventArgs to indicate as such. To check for the absense of an event, you'd have to fire up a timer for some arbitrary amount of time (highly dependent upon the scanning hardware) and call it "finished" if the timer elapses without another page being scanned, which seems like a major kludge. I know the TWAIN specification includes messages sent to the calling window which indicate when scanning is complete, so is it necessary to catch and process these ourselves to determine when scanning is complete?
Thanks in advance for any insight.
-Dewitt
#6
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Sunday, September 7, 2008 3:05:56 AM(UTC)
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Dewitt,
You can check the CAP_FEEDERLOADED which is supported by all sources with feeder devices. If it return false, this means that there are no more documents in the feeder and the twain finished scanning, if it returns true, this means that there are still documents to be scanned.
#7
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Sunday, September 7, 2008 3:11:46 AM(UTC)
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Hi Adnan -
Thank you for the prompt reply. I will give this a try but it sounds like what I'm after.
Thanks again,
-Dewitt
#8
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Thursday, October 9, 2008 8:19:00 AM(UTC)
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Dewitt - Did you ever get this to work? I have attempted to implement the FEEDERLOADED capability, but it always returns 'True', even when the feeder tray is empty. Did you by chance experience this same issue?
#9
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Thursday, October 9, 2008 8:39:03 AM(UTC)
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newdawn -
I actually abandoned the LeadTools library and wrote my own TWAIN implementation so that I could have complete control over everything. However, if I recall correctly, at the time I posted the above message I had a misunderstanding about the Aquire() method LeadTools provides and didn't realize it was a blocking call until all scanning was complete. At the time I thought it was asynchronous and images should be processed with an event handler.
-Dewitt
#10
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Monday, October 13, 2008 6:15:49 AM(UTC)
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newdawn,
My colleague Yasir has responded through support email and
suggested you check that the CAP_FEEDERENABLED capability is
set to True before checking FEEDERLOADED. Did you try that?
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