Hi, On Sun, Feb 23, 2003 at 10:25:46AM +1100, Martijn van Oosterhout wrote: > On Sat, Feb 22, 2003 at 03:54:37PM +0100, Henning Meier-Geinitz wrote: > > Some tips are also in doc/backend-writing.txt. E.g. for writing > > portable code. > > Thanks, I found them. I'm reading them now. Actually, I have one addition > for the backend-writing.txt
Thanks, I will add it. > > > Can I safely assume the caller of sane_read will provide a buffer >10K. > > > Probably not hey? So I have to buffer possibly down to the subpixel level. > > > > No. The buffer can be as low as 1 byte. In backends that need to do > > image manipulation, usually a buffer of one or multiple scan lines is > > used. Especially if you need to do line distance correction (CCD > > scanners), you may need 10 or more lines of each color. > > Heh. I wonder if all backends really support a buffer that small. Nice > stress test :) scanimage -T and frontend/tstbackend both try 1 byte per read scans. So every backend in the sane distribution should be able to do this :-) Bye, Henning