Improve pdf creation: implement `--pages-per-dict`, support for background images

[akryukov]

Hi,

I propose a patch which changes jbig2 behavior at two aspects. First, the files generated in the "-p" mode now retain their original names, and just the extension is changed (I use ".jbig2", but whatever else would be OK). A numerical suffix is added in case of name clashes (or for images which go from multipage tiff files). For this reason the 'basename' parameter is gone. The reason for this change is that source images may have some accompanying files (such as background images previously separated with a scan processing application). In such case file names contain some useful information which should not be lost during the processing/conversion.

The second change allows to generate more than just one symbol dictionary, so that the loading speed for large PDF files can be increased. There is now a new option (-P, --pages-per-dict), which specifies how many pages should be processed at the same pass. The default value for this parameter is 15.

I also propose a modified version of pdf.py, implementing support for background images, which can be combined with the foreground mask in the same pdf file. Several graphical formats (PNG, TIFF, JPEG) are supported. It is possible either to use graphics stripped by jbig2 at the previous stage, or prepage images separately in a different application, given that the file names follow the same convention.

BTW it might be reasonable to rename pdf.py to something more meaningful, so that the script could be safely installed somewhere into the PATH.

The files can be downloaded here:
http://www.thessalonica.org.ru/downloads/jbig2.patch.gz
http://www.thessalonica.org.ru/downloads/pdf.py.gz

[DingoDog]

I downloaded your patch, and tried patching, but these errors are returned to me:

patch -p0 < jbig2.patch

can't find file to patch at input line 4
Perhaps you used the wrong -p or --strip option?

The text leading up to this was:

|diff -ur agl-jbig2enc-git.orig//jbig2.cc agl-jbig2enc-git//jbig2.cc
|--- agl-jbig2enc-git.orig//jbig2.cc 2009-11-05 11:27:45.000000000 +0300

|+++ agl-jbig2enc-git//jbig2.cc 2009-11-07 00:31:39.000000000 +0300

File to patch: jbig2.cc
patching file jbig2.cc
Hunk #1 FAILED at 39.
Hunk #2 FAILED at 191.
Hunk #3 FAILED at 304.
Hunk #4 FAILED at 354.
Hunk #5 FAILED at 393.
Hunk #6 FAILED at 431.
Hunk #7 FAILED at 571.
7 out of 7 hunks FAILED -- saving rejects to file jbig2.cc.rej

[akryukov]

That's my fault: the patch was prepared according to my directory tree (i. e. it assumed the unpatched sources have been downloaded into a directory called agl-jbig2enc-git). I have now uploaded a corrected version of the patch at the same location. This version should be placed directly into the directory with jbig2enc sources before you execute

patch -p0 < jbig2.patch

[DingoDog]

thanks (also for your fonts, specially "Old Standard", that I use)

patched, this is the output:

patch -p0<jbig2.patch

patching file jbig2.cc
Hunk #1 succeeded at 37 (offset -2 lines).
Hunk #3 succeeded at 302 (offset -2 lines).
Hunk #5 succeeded at 391 (offset -2 lines).
Hunk #6 FAILED at 429.
Hunk #7 succeeded at 572 (offset -1 lines).
1 out of 7 hunks FAILED -- saving rejects to file jbig2.cc.rej

after patched I tried to build, but something is wrong

make

g++ -c jbig2enc.cc -I../leptonlib-1.58/src -Wall -I/usr/include -L/usr/lib -O3
g++ -c jbig2arith.cc -I../leptonlib-1.58/src -Wall -I/usr/include -L/usr/lib -O3
g++ -c jbig2sym.cc -DUSE_EXT -I../leptonlib-1.58/src -Wall -I/usr/include -L/usr/lib -O3
ar -rcv libjbig2enc.a jbig2enc.o jbig2arith.o jbig2sym.o
a - jbig2enc.o
a - jbig2arith.o
a - jbig2sym.o
g++ -o jbig2 jbig2.cc -L. -ljbig2enc ../leptonlib-1.58/src/liblept.a -I../leptonlib-1.58/src -Wall -I/usr/include -L/usr/lib -O3 -lpng -ljpeg -ltiff -lm
jbig2.cc: In function 'int main(int, char**)':
jbig2.cc:501: warning: format '%s' expects type 'char_', but argument 3 has type 'char_ ()(const char)throw ()'
jbig2.cc:538: warning: format '%s' expects type 'char_', but argument 3 has type 'char_ ()(const char)throw ()'
jbig2.cc:553: warning: format '%s' expects type 'char_', but argument 3 has type 'char_ ()(const char)throw ()'
jbig2.cc:564: error: 'pages_to_compress' was not declared in this scope
jbig2.cc:567: error: 'cnt' was not declared in this scope
jbig2.cc:578: error: 'cnt' was not declared in this scope
jbig2.cc: At global scope:
jbig2.cc:207: warning: 'char* replace_suffix(char_, const char_)' defined but not used
jbig2.cc:220: warning: 'char* get_page_or_dict_name(char**, int, const char_, int)' defined but not used
jbig2.cc:273: warning: 'int is_tiff_format(int)' defined but not used
make: *_* [jbig2] Error 1

[akryukov]

DingoDog

It looks like you are attempting to patch a wrong version. You should download the most recent sources from git:

git clone git://git://github.com/agl/jbig2enc.gitgithub.com/agl/jbig2enc.git

[DingoDog]

Many thanks for your answer first of all

Yes, I tried to apply patch to jbig2 0.27 downloadable at:

https://github.com/agl/jbig2enc/tarball/0.27

Now, I used GIt but it seems fail:

git clone git://git://github.com/agl/jbig2enc.gitgithub.com/agl/jbig2enc.git

Initialized empty Git repository in /root/NewDir/jbig2enc/.git/
fatal: Unable to look up git (port ) (Servname not supported for ai_socktype)
fetch-pack from 'git://git://github.com/agl/jbig2enc.gitgithub.com/agl/jbig2enc.git' failed.

this command has instead worked

git clone git://github.com/agl/jbig2enc.git src

---

git clone git://github.com/agl/jbig2enc.git src

Initialized empty Git repository in /root/NewDir/src/.git/
remote: Counting objects: 118, done.
remote: Compressing objects: 100% (112/112), done.
Indexing 118 objects...
remote: Total 118 (delta 75), reused 0 (delta 0)
100% (118/118) done
Resolving 75 deltas...
100% (75/75) done

---

and applying patch has been successful

I then downloaded leptonica libs 1.63 and built jbig2enc (not yet tried) I can not wait to try it! meantime thanks again for your patch and your answers

EDIT:

Tried, it is working, only, when I use your modified pdf.py it says

File "/root/my-applications/bin/thessalonica-pdf.py", line 27, in
from PIL import Image

So I think I have not Python Imaging Library (PIL), it is right? I'm currently looking for this but I have yet found

EDIT:

I built PIL from sources and launched before

jbig2

and then your modified pdf.py

pdf.py *.jbig2 out>test.pdf

but resulting pdf has b/w images, I thought the pictures were in color, maybe I did not understand the meaning of your sentence:

"which can be combined with the foreground mask in the same pdf file"

how can this be done? (mixing foreground mask with b/w text) excuse me for my ignorance

[mistydemeo]

@akryukov, I recognize this is a very old issue, but wanted to mention I'd consider pulling this in mistydemeo/jbig2enc.

Since you've implemented both the symbol page limiting functionality and the image/text layer functionality in PDFBeads, do you think there's anything significant here that is still worth including directly in jbig2enc? I think the layer functionality is out of scope for pdf.py, since that's really just a simple demo utility - I would rather avoid adding new dependencies to it.

The symbol page feature seems useful, however. Probably still within scope of jbig2enc. If you think it's still relevant, would you mind rebasing your patch on the current master at my fork and submitting a pull request there?

Thanks!

[zdenop]

For http://www.thessalonica.org.ru/downloads/pdf.py.gz I got error message (File Not Found!).
Can you (or somobody else who has a copy) post this file once again?

[akryukov]

On Fri, 29 Jun 2012 06:46:32 -0700
zdenop wrote:

For http://www.thessalonica.org.ru/downloads/pdf.py.gz I got error
message (File Not Found!). Can you (or somobody else who has a copy)
post this file once again?

It is obsolete and no longer needed: try pdfbeads (which works even with
unpatched jbig2enc) instead.

Regards,
Alexey Kryukov

Moscow State University
Faculty of History

[DingoDog]

download from here:

http://ge.tt/7GmUTpJ/v/0

[zdenop]

thanks - I am aware and glad for pdfbeads.
I just want to evaluate your proposed functionality and probably merge it into my fork of jbig2enc...

BTW: I am not sure if it is a good idea to use .jbig2 or jb2 extension for current jbig2 output. I was not able to read this files with stduviewer (it should be able to open and read jbig2 files). I plan to do more test on this.

[akryukov]

On Fri, 29 Jun 2012 11:48:44 -0700
zdenop wrote:

BTW: I am not sure if it is a good idea to use .jbig2 or jb2
extension for current jbig2 output. I was not able to read this files
with stduviewer (it should be able to open and read jbig2 files). I
plan to do more test on this.

Of course you are absolutely right here, but... can you propose another
meaningful extension for those files?

Regards,
Alexey Kryukov

Moscow State University
Faculty of History

[galex751]

Hi Mr Kryukov, I'd like to test your patch with -P parameter but I'm not able to download from http://www.thessalonica.org.ru/downloads/jbig2.patch.gz. Could you post the sources somewhere in order to be able to donwload?

Many Thanks
Alessandro

[yb85]

Dear @akryukov ,
I am very interested by your patch as I encounter some serious slowdown on large documents (>100p). Would it be possible to post it online ?
thanks
yann

[DingoDog]

Dear @akryukov ,
I am very interested by your patch as I encounter some serious slowdown on large documents (>100p). Would it be possible to post it online ?
thanks
yann

Sorry for delay. I uploaded here the patch:

http://ge.tt/8BllCy23

[DingoDog]

Hi Mr Kryukov, I'd like to test your patch with -P parameter but I'm not able to download from http://www.thessalonica.org.ru/downloads/jbig2.patch.gz. Could you post the sources somewhere in order to be able to donwload?

Many Thanks
Alessandro

I sent a full pack with patch and other goodies to mail address you provided to me on diybookscanner forum