I m trying to specify programmatically settings for scanning in TWAIN session. Because amount of code here would be significant I m going to try to explain the problem without pasting the entire code. I hope there s someone good at TWAIN to help me....
To do scanning settings I m using lowlevel calls to native Twain library. The scanner is HP Scanjet 7000. At the moment I m stuck with setting colour and bit depth options. What is important I haven t had any problems with two other scanners. just this model.
According to the specification before setting ICAP_BITDEPTH (page 480) I need to set ICAP_PIXELTYPE (535). So first I m asking for the list of supported PixelTypes... And they are TWPT_BW (Black&White), TWPT_GRAY (Gray) and TWPT_RGB (RGB). Since I want to get black&white scans I m trying to set this capabilityt to TWPT_BW. This results in an error and I don t understand why. As I said in two other models this is working.
Is it possible that this scanner disallows setting capabilities like this?
TWAIN Specification: http://www.twain.org/docs/TWAIN_2_1_Spec.pdf