Home › Forums › TWAIN Classic › how to set contrast/brightness?
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I try to set ICAP_CONTRAST or ICAP_BRIGHTNESS when scanning without showing user interface. Return code is TWRC_SUCCESS but resulting image is with contrast/brightness at default values.
Any ideas?
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Loratab Rehab Forumhe he facing same prob………..
Same problem I’m facing when I try to change brightness/contrast.
I have two scanners Epson Stylus returns success but setting is not visible in the scanned image. Epson Expression 10000XL returns twrc_failure.
If anyone has a solution it would be great.
Sometimes I wonder whether there are other CAPs that shud be set before this. If so, someone please let us know.
Hello! I had a problem similar to yours: one source returned twrc_success, but another – twrc_failure. Then I changed value of ConType in TW_CAPABILITY and received twrc_success for that source.
Hi Victor,
Thanks for the reply.
What is the value that you set in ConType to get TWRC_SUCCESS?
Still, did you get the changes affecting the scanned image?
In both scanners that I have, although one returns TWRC_SUCCESS, I can’t get the changes to affect the scanned image.
Not only that I’m struggling to set TRUE for ICAP_AUTOMATICBORDERDETECTION. Sometimes I wonder whether these are actually supported in Epson’s twain DSW. I hope somebody will be able to help me in this.
Best Regards
Hi ff.in.twain,
See
http://www.codeproject.com/dotnet/twaindotnet.asp
May be you’ll find answer there.Hi Victor,
The TwainGUI project given here is using the entry points in twain32.dll in C#. I’m using win32 C++ and using the twain proc address and capability controlling as in twain specification.
Do you think that win32 based method does not work. How would I find the entry points of twain32.dll, so that I can use C#.
Best Regards
Hi ff.in.twain,
I wrote my project in C#, that’s why I gave that link. If you use C++, you can look through article and sources on
http://www.codeproject.com/audio/twaintest.asp
I think, you shouldn’t change C++ to C#, because it is easier to use TWAIN in C++ than in C#.Hi Victor,
Thanks a lot I went thru that source code of Win32 C++ application. The problem with that (and most other samples) is that they use the epson’s own GUI for most of controlling. They set the ShowUI feature as true and hence the brightness, gamma etc are controlled using Epson GUI. But my work has the pre-condition that none of the Epson GUIs can be used. I have to set the value of ICAP_BRIGHTNESS using capability setting. But that’s where it does not work.
Similarly I can’t set the capability for auto cropping and auto rotating. In fact there is no capability that I can set using win32 C++ Twain interface of Epson 10000XL.
It seems like I’m facing a big wall and no one has gone beyond here. Perhaps to give up Twain altogether might be my option.
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