31 Dec
2011
31 Dec
'11
3:42 p.m.
On Dec 31, 2011, at 4:50 AM, David Griffith wrote:
Since several people here do this kind of thing, I
figured I'd ask here.
I'm trying my hand at scanning stuff to PDF. The only thing I seem to find for doing
this in Linux is Simple Simple Scan. I'm scanning in photo mode because text mode is
unacceptably grainy. My problem now is converting the resulting jpg into a pdf.
ImageMagick is the obvious tool for this, but no matter what I do, the resulting pdf is
grainy. How can I tell ImageMagick to not diddle with the quality?
--
David Griffith
There are some notes about this on the home page of bitsavers.org. Among other things
they say:
Post-processing is done using Lemkesoft's Graphic Converter
TIFF to PDF conversion is done using Eric Smith's tumble
The preferred form for any contributed text scan is as a collection of lossless
Group 4 fax compression (ITU-T recommendation T.6) images saved as TIFF
files with a minium scan resolution of 400 dpi.
Lower scan resolutions produce noticable artifacts if a page needs to be
straightened in post-processing.
Lossy compression formats, such as JPEG, should NEVER be used to save pages
of text, since the compression format destroys edge resolution and contrast
would make it difficult to OCR in the future.
-Jeff