20 May
2005
20 May
'05
11:20 a.m.
We've now named quite a lot of applications and concepts about how to
handle scanned documents. I'd like to get the big picture:
--
here is the current workflow that I'm using
Ricoh IS520 30page/minute duplex B&W scanner that can handle up to 11 x 17
with crappy Windows scan app (under vmware) generates even / odd pages into
two separate directories. Since it turned out that scanning wide-edge first
results in straighter scans, I need to postprocess front and back separately
since the backs are flipped 180 deg.
The tiffs are on a shared file system with my Mac. I do all of the cleanup
on there with Graphic Converter. I have a bunch of scripts I run over the files
to produce a single directory with the pages brought to size and the boarders
cleaned up. I then cull the dups/bad scans, check that I didn't miss any pages
then save the files with the page number as the file name. Then I squirt the dir
back over to the linux box (since tumble is little-endian only) and say:
tumble -b %F * ../file.pdf
Copy it back over to the Mac, add it to the postprocessed scans and put the
whole thing in a 'to be archived' dir where it is saved to DVD-R
If there are pages that can't be scanned on the Ricoh, I do those separately
on a Mustek 11x17 flatbed.
Then, ftp the pdf to bitsavers, and update the index files.
20 May
20 May
12:06 p.m.
New subject: Inventory for handling scanned documents (was: Better indexing on bitsavers)
On Fri, 2005-05-20 at 11:20 -0700, Al Kossow wrote:
We've now named quite a lot of applications and
concepts about how to
handle scanned documents. I'd like to get the big picture:
--
here is the current workflow that I'm using
Al,
what do you do with "fold out" pages within documents (e.g. A4 doc that
has a handful of fold out A3 schematics in)?
Do you scan the two halves of the A3 pages and join them together as a
single image, leave them as two seperate A4 scans in the doc, or scan
them totally seperately on an A3 scanner before including in the
'output' doc?
I've never quite decided what to do about this myself...
cheers
Jules
25 May
25 May
11:53 a.m.
New subject: Inventory for handling scanned documents (was: Better indexing on bitsavers)
On 20 May 2005 at 11:20, Al Kossow wrote:
Since it turned out that scanning wide-edge first
results in straighter
scans....
In preparation for scanning and PDFing the 200-odd HP manuals in my
possession, I've been experimenting with batch image-processing programs.
For deskewing scans, the Leptonica library at:
http://www.leptonica.com/
...provides a simple solution that works quite well. Deskewing is
literally little more than calling the "pixRead", "pixDeskew", and
"pixWrite" library functions.
For pages containing text and screened photos, I scan once at 600 dpi
bilevel (for the text) and a second time at 200 dpi grayscale for the photo
using the descreening feature of the (horrible) HP imaging software that
came with the scanner. Manually, I erase the screened area from the first
image and crop the second, saving the latter as a JPEG. I've modified
"tumble" to composite images, so the resulting PDF page has the TIFF G4
text background with the JPEG photo superimposed.
I wrote a simple masking program to clean up the edges of the scanned
images. I wrote another program that takes a directory of image files,
parses the filenames for section, chapter, and page number information
encoded in the names, and creates a "tumble" control file to create the PDF
with appropriate bookmarks, page labels, and blank pages -- the latter to
allow for easy duplex printing (I've also modified "tumble" to create blank
PDF pages instead of embedding a blank TIFF page image).
Finally, I use Ghostscript to linearize the tumbled PDF.
The only significant manual work is rescanning the photos in order to
descreen them. I'd like to find a batch descreener that would take a
bilevel screened image file and produce a grayscale image. The Leptonica
library has such a function, but my first attempts yielded visible Moire
patterns. I need to investigate further.
-- Dave
27 May
27 May
11:17 a.m.
J. David Bryan wrote:
using the descreening feature of the (horrible) HP
imaging software that
This is the Nth time I've seen the scanner software blamed (and rightly so). A
long time ago I standardized on Microtek scanners because their software (in
Advanced mode) is some of the best scanning software I've ever used. It won't
deskew, but it does practically everything else (descreening, multiple output
targets from different regions/depths of the same source item, white/gray/black
point balance, etc.). The scanners are very reasonable ($130 for a decent one,
$300 if you want one with embedded ICE technology).
One thing I hadn't seen mentioned so far is the importance of doing as much
correction as possible within the scanner software BEFORE it gets to the
pc/mac. This is because most scanners are 36-/48-bit internally and can
perform much finer adjustments in that colorspace before it gets converted to
24-bit while being sent to the computer.
--
Jim Leonard (trixter at oldskool.org) http://www.oldskool.org/
Want to help an ambitious games project? http://www.mobygames.com/
Or check out some trippy MindCandy at http://www.mindcandydvd.com/
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participants (4)
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aek＠bitsavers.org -
jdbryan＠acm.org -
julesrichardsonuk＠yahoo.co.uk -
trixter＠oldskool.org