TWAIN Brightness

Discussions about TWAIN & WIA scanning in GdPicture.NET using GdPictureImaging.
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TWAIN Brightness

Post by nsk88 » Fri Apr 30, 2010 3:21 am

According to the document - GdPicture_NET Document Imaging SDK.pdf, the function GdPictureImaging.TwainSetBrightness is used to set the scanner brightness, where the available range is from -1000 to 1000. However, I noticed that some scanners has brightness settings with the range of 1 to 255. Is it possible to change the range from “-1000 to 1000” to “1 to 255”. Please advice.

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Re: TWAIN Brightness

Post by Loïc » Fri Apr 30, 2010 10:15 am


The range -1000 1000 is defined by the TWAIN specifications. Some scanner use they own range. Can be [0;255] [-255:255] ...

You will be able to retrieve your range using the TwainGetCapRangeNumeric method:

Code: Select all

        Dim nMin, nMax, nStep As Double

        oGdPictureImaging.TwainGetCapRangeNumeric(TwainCapabilities.ICAP_BRIGHTNESS, nMin, nMax, nStep)
Kind regards,


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