[sane-devel] Re: request for extra xsane functionality

[Oliver Schwartz]

Hi,

> When you scan a DIN-A4 page with 200x200 dpi and save it e.g. as a
> tiff file then you get an image with about 1700 x 2200 pixels. At
> this point there is no relation to a size in millimeter,
> centimeter, inch or DIN-A3 or something like that.

I don't think this is completely true. Tiff allows you to add a 
"Resolution" tag that specifies the pixels/inch. So even after saving 
as a tiff file it's possible to deduce it's original size. The tag, 
btw, is set correctly by xsane (run tiffinfo on a tiff file saved 
from SANE).

> But there will be nothing like "Scale to DIN-A4", this is not
> possible when you do not know the size of a pixel!

If you manage to get the resolution (in DPI) of the display then you 
could even display the image in it's original size. Don't ask me how, 
but I think it's possible for X11R6.

/Oliver