[sane-devel] SANE API evolution

[stef]

	Hello,

	here are the features I think next revision of SANE's API should contain:

	There should be at least these user visible features:
	- new image formats such as jpeg
	- new frame types such a IR
	- warming up support
	- a way to tell user that the scan is uncalibrated (for sheet-fed scanners 
not yet calibrated, or if calibration is not developed).
	- a mean to require an external calibration sheet from the user in the case
	  of sheet-fed scanners' calibration

	Useful but non-blocking:
	- better backend version reporting  (for meta backends case). 
	- capability reporting, for instance telling that some feature (gray scan, 
line art, ...) is emulated would allow a frontend to choose it's own 
emulation.
	-better semantics for sane_cancel()

	Internal improvements that could be nice to have:
	- defining an enum SANE_State={idle, scanning, ... } which would help to
	  write code in sanei_* functions and factor some code out of backends

	There have been talks about improving the API for more than 6 years now, and 
nothing conclusive has come up. I hope a good compromise can be reach soon. 
Maybe deciding of the features to add first would help. We could care of the 
technical problems after. 

Regards,
	Stef