Scanning Scores with a Mac

[Lyle Neff]

Correction: I won't be able to use Gimp, or something like it, until my desktop computer at home is upgraded. Seems Gimp needs a lot more memory and/or processor speed than my 6-year-old PC can handle.

So, unfortunately, my active contributions will be of less-than-desirable image quality for the foreseeable future.

But I'll try to make sure to archive all of my "raw" scans for later.

[Peter]

Can't you bypass compression in the imaging program by using a pdf tool that does the compression? (in windows) I always let acrobat do the CCITT.

[Lyle Neff]

Can't you bypass compression in the imaging program by using a pdf tool that does the compression? (in windows) I always let acrobat do the CCITT.

Well, yes, but I also want to save space on my storage device(s), so I'd need to compress the TIFs after editing at some point if I want to preserve them.

(I use a scanner/photocopier at the library which apparently compresses each TIF. After I edit and re-save in Arcsoft PhotoStudio, the file-size balloons out of control.)

[imslp]

Some programs have horrible ways of compressing. For example, some will compress monochrome to grayscale JPEG, which might account for the ballooning of size when uncompressed.

[Carolus]

Since there was a mention of Mac's here, I though it might be worth mentioning the inexpensive program Graphic Converter, which can be very useful for batch processing TIFFs into CCIT level 4 bitmaps, for converting color and grayscale scans to bitmap (and vice versa), plus some fairly decent editing features.

Not as good as Photoshop to be sure, but also about 1/10th the price.

[Vivaldi]

To Daphnis,
I'm not actually using a flat-bed scanner, I'm using a Canon ImageClass multi-function printer that has a scanner. I suspect that age might be a factor as well, since I bought this 3-4 years ago. I think I'll have to invest in a high quality flat-bed scanner, which can scan 600dpi in a few seconds rather than half a minute (which is the time my scanner needs).

[carmar1791]

Does someone know the comand line to convert ccitt group 4 using imagemagick?
The default convesion ("convert input.pdf output.tiff") is very bad,useless for loss of quality.
Conversions made by Gimp are bad too (pdf to tiff).Is there a way to set gimp/imagemagick to convert at level ccitt group 4 ?
Thank'you
Carmar

[horndude77]

For compressing a monochrome tiff this works fine for me:
convert $1 -compress Group4 $1

The problem is extracting the images from the pdf. There is pdfimages which creates a bunch of pbm's. Unfortunately you lose the original image dpi. If you know that you can do something like this (thrown together quickly):

Code: Select all

#!/bin/sh
#Usage $0 [pdf file]-
PREFIX=prefix
pdfimages $1 $PREFIX
for i in $PREFIX*.pbm
do
    convert -density 600x600 $i -negate -compress Group4 `echo $i | sed -e 's_pbm$_tiff_'`
done
tiffcp $PREFIX*.tiff out$PREFIX.tiff
tiff2pdf out$PREFIX.tiff -z -o Compressed_$1
rm $PREFIX*
rm out$PREFIX.tiff

I believe feldmahler used to have a similar script.

[horndude77]

Here's the script I was thinking of: http://imslp.org/wiki/Optimizing_PDF_Compression

[carmar1791]

Thank you.It will be hard to understand all now and atonce. (I have just switch to linux).
Thank you again

Ciao

Carmar