For some reason, I can’t find in the TWAIN spec how you ask a TWAIN DS which TWEI_ codes it supports. The 1.9 spec seems to imply that after scanning an image, you ask for all the TWEI_ codes you might want to know, and the DS just marks the ones it doesn’t support with TWRC_INFONOTSUPPORTED. Surely… that’s not the only way to find out what the driver supports?
I checked ICAP_EXTIMAGEINFO, but it’s just a BOOL.
I don’t remember reading that you could ask which were supported ahead of time. When I’m interested in that twei details I ask for them one by one all the way thru an enumeration in a loop – it might not be most efficient, but so far I have found it to be pretty quick ~ around 150ms per image to run the Get on each of the 63 standand items (if my enum is right).
..but I guess that doesn’t really answer your question – sorry. If you find the method, post back. And disregard the part of my pm where I said I never got that to work, I found the code and it works – I just don’t gather that info very often.
Huh – well, I don’t mind doing something like that. I’ve been trying to figure out a nice way to integrate this into EZTwain, without using callbacks or notification messages. I’m thinking I’ll let the application tell me what info it would be interested in, then I’ll ask the DS for all that when the time comes, and cache anything that gives a ‘hit’ – then the app can ask me later what I received. Sort of like playing Risk by e-mail… except you don’t know what countries you control at the start of your turn!
I’ll have to find a driver that actually supports extended image info – I guess I can test with the Kodak simulator.