Hi, On Mon, Dec 09, 2002 at 06:21:30PM -0500, Matto Marjanovic wrote: > >this is very similar to the frame type. In fact you do not change a lot with > >this. When we want to remove the frames then I suggest to do it right: > >only channel-interleaved data, no planes in SANE_(FRAME_)RAW. > > Hi, Oliver, > > The difference isn't so much the data format as the code flow: all the > planar data is returned after a single sane_start(), and the multi-frame > flags for determining which 'frame' is currently being scanned can be > removed from the standard.
I support this proposal. That was my original intention. I also don't like the mulitiple call of sane_start. This way, it's just a differnt image format. No problem at all. No need to call sane_start three time, no need to call frames. So we have only the image and the channel paradigm. One image per sane_start. One ore more channels per image. The channels can be ordered either interleaved or as planes. > >In fact this makes the sane standard more simple. Three pass scanners > >are not produced any more. > > But people still keep using them (and sending bug reports). :) And we want to wtite some sane2-sane1 compatibility dll, so we shouldn't get too incompatible, if possible. > I envision three SANE_Frame types: > > o SANE_FRAME_PACKED --- sample-interleaved channels, following all the > current RAW specs. > o SANE_FRAME_PLANAR --- planar channels, following all the current RAW > specs. > o SANE_FRAME_MIME --- opaque image data, with a MIME type. > > Each sane_start() cycle would return a single frame, and each frame would > be a complete image. This also avois explanations that SANE_FRAME_MIME can only use one frame. An alternative would be to use only two frame types SANE_FRAME_RAW and SANE_FRAME_MIME and put the plane/interleaved distinction in the format_desc: "red:8,green:8,blue:8": interleaved "red:8;green:8;blue:8": planes BUT: Someone could try to use: "red:8,green:8;blue:8": well? And I guess we don't want that confusion with ";" and ",". So the three distinct types seem to be easier. Bye, Henning
