Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Search found 27 matches

by RichardT
13 Mar 2014, 23:09
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny DJVU files

Another interesting one from tonight. OConnor, Understanding Jung, 162 pages of black-and-white text. ClearScan PDF: 3.1MB ... DJVU with OCR: 1.4MB ... DJVU without OCR 800kb. All 600dpi. So was it a waste of time scanning my library to PDF if I've decided to slog through the djvu creation process a...
by RichardT
13 Mar 2014, 21:58
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny DJVU files

I continue to mass-convert my scanned books to djvu. These are not the ugly low-quality scans that I have kind of made a hobby out of dressing up. These are all 600dpi sheet-fed scans of books which have had their spines chopped off. Recall that they were Adobe ClearScan files before, and I was gene...
by RichardT
12 Mar 2014, 11:31
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny DJVU files

As I mentioned earlier in this thread, djvumake is very particular about the size of subsampled images, relative to the original. I used to pad/chop ALL of the pages to be divisible by my sampling factor, but that's kind of a pain. Since then, I've changed my workflow so it's not necessary. I though...
by RichardT
10 Mar 2014, 15:54
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny DJVU files

Incidentally, while I'm here, recently I've taken quite a few bad scans with tons of jpeg artifacts and made them pretty compressible with a command like this: convert.exe example.png -white-threshold 85% -ordered-dither o2x2,2 -morphology Erode:1 Disk:1 +dither -remap map.gif out/example.png The pr...
by RichardT
10 Mar 2014, 13:36
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny DJVU files

It was interesting to see how you turned away from DjVu to PDF. Sorry I haven't been back here for quite some time. After some trial and error manually making PDFs as I showed in my posts, I finally decided life was too short and bought Acrobat. I then destructively scanned all my books over the ne...
by RichardT
07 May 2012, 11:02
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny DJVU files

Today's food for thought. One possible advantage of PDF over DJVU is that you can position small images inside of a page, instead of having a page-sized background layer. I was wondering how much this mattered, since a large white area of a page should compress down pretty well. So, I screengrabbed ...
by RichardT
06 May 2012, 18:49
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny DJVU files

As a side note, I learned to use tesseract for djvu from djvubind and other websites. They generate "box" and "text" outputs, and then try their best to find the correspondence between them. That means doing the OCR twice, and even though I can't hardly believe it, the output doesn't always match. I...
by RichardT
06 May 2012, 18:35
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny DJVU files

Thanks, hopefully as I get my workflow going smoothly, I'll put all the code I'm using out on my website with some explanations. Last night I made a custom version of jbig2 that makes the output file names resemble the input file names (instead of just counting up from .0000). This is important beca...
by RichardT
05 May 2012, 23:17
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny PDF files

Update: after a couple days, I now have a python3 script that takes jbig2 output as a mask, and can combine that with background and foreground files of a much lower DPI. The result, and the process that leads up to it, is very much like the DJVU workflow I had before. A couple notes: imagemagick wi...
by RichardT
03 May 2012, 17:25
Forum: Software
Topic: Learning to Create Tiny DJVU files
Replies: 35
Views: 42624

Re: Learning to Create Tiny DJVU files

Follow-up. Oddly it wasn't immediately obvious which command I should use to split my djvu files into TIFs. So, I wrote a small script to do the work: #!/bin/bash numpages=$(djvm -l $1 | grep 'PAGE #' | wc -l) echo "$numpages pages in the DJVU..." for x in $(seq 1 $numpages) do pagename=$(printf "%0...