Oliver Schwartz wrote: > Hi, > > On Wednesday 25 September 2002 21:05, Henning Meier-Geinitz wrote: > >>Hi, >> >>On Wed, Sep 25, 2002 at 11:16:15AM -0700, David Mosberger-Tang wrote: >> >>> Oliver> I think that makes sense. When a backend really does >>> Oliver> support this then it can send it as 8 bit rgb image. >>> >>>Do we know for a fact that there are no high-speed devices out there >>>that produce, say, dithered 1-bit data? If not, inflating the storage >>>and bandwidth requirements for such devices by a factor of 8 seems >>>like a non-trivial issue. >> >>The older Mustek SCSI scanners could send 1 bit per color RGB so there >>are devices that can. > > > The Snapscan scanners also support 1 bit per color. You can even send your > own > dither matrix to the scanner. (In theory, that is. I never quite got it to > work.) However, the backend will expand the data to 8 bit/color, so original > problem does not appear in the snapscan backend.
Same with Sharp scanners and the Sharp backend. The scanners can produce 1 bit/sample RGB data, but the backend expands that to 8 bit/sample, because [x]scanimage did not write useful output files, at least at the time, when I implemented the 1 bit mode. Abel
