Add "Drawing" / "Greyscale" Mode
Using the Text Mode within Simple Scan the incoming 8bit greyscale data from the device is somehow compressed. In text-intensive scans that's quite nice as the resulting pdf files are smaller. On the other hand if scanning tables or formatted stuff with grey values it's sub-optimal, as it results in artifacts / visually non-pleasant results.
I would suggest to introduce a new "Drawing" or "Greyscale" mode which saves the whole single-channel bit-depth of the incoming stream from the device. The general idea was already given in 647d3dea where it was suggested to use the full bit-depth within Text Mode. I'd suggest to re-implement (under consideration of #170 (closed)) and make it selectable by introducing a new mode.
Thanks and best Regards Dominik