On 28/02/2019 15.10, Marco Calistri wrote: ...

2 - Why XSane-Scanner Tool produces so large PDF files, also if we set low resolution at 150 DPI?

What is the exact name of the program? I see "xsane", but not "XSane-Scanner". The size of the PDF will depend on the resolution requested. For example, I scan an A4 page at 300 dpi and I get a 3.6 MiB PDF file, which is reasonable. Repeating with PNG the size is 3,5MiB. You can go to Preferences menu and you get a dialog. There, on filetype tab you can select some default options for each file type, like compressing PDF or not, or how much to compress JPG and PNG.

I found a script (http://www.alfredklomp.com/programming/shrinkpdf) on the Web which uses ghostscript which reduce a 15.2Mb Xsane PDF to just 1.4 Mb in size, so IMHO XSane developers should think to include a more efficient compression routine to avoid the scanned PDF being created with a so very big size.

Thanks and regards,

I prefer to generate PNG, and then convert to DJVU with a script. -- Cheers / Saludos, Carlos E. R. (from 15.0 x86_64 at Telcontar)