This is an encoder for JBIG2.
JBIG2 encodes bi-level (1 bpp) images using a number of clever tricks to get better compression than G4. This encoder can:
- Generate JBIG2 files, or fragments for embedding in PDFs
- Generic region encoding
- Perform symbol extraction, classification and text region coding
- Perform refinement coding and,
- Compress multipage documents
It uses the (Apache-ish licensed) Leptonica library: http://leptonica.com/
You'll need version 1.68.
The refinement coding causes Acrobat to crash. It's not known if this is a bug in Acrobat, though it may well be.
See the jbig2enc.h header for the high level API, or the jbig2 program for an
example of usage:
$ jbig2 -s -p -v *.jpg && python3 jbig2topdf.py output >out.pdf
to encode jbig2 files for pdf creation. If you want to encode an image and then view output first to include in pdf
$ jbig2 -s -S -p -v -O out.png *.jpg
If you want to encode an image as jbig2 (can be view in STDU Viewer on Windows) run:
$ jbig2 -s feyn.tif >feyn.jb2
- installed leptonica including development parts
- installed cmake or [autotools] (https://www.gnu.org/software/automake/manual/html_node/Autotools-Introduction.html)
- installed C++ compiller (gcc, clang, MSVC)
- installed git
Note: cat, rm and dos2unix tool are part of git for windows. You can add them to your path with set PATH=%PATH%;C:\Program Files\Git\usr\bin. Adjust path f:\win64 to your leptonica installation.
"c:\Program Files (x86)\Microsoft Visual Studio\2019\Community\VC\Auxiliary\Build\vcvars64.bat" x64
set INSTALL_DIR=f:\win64
set INCLUDE_DIR=f:\win64\include
set LIB_DIR=f:\win64\lib
set PATH=%PATH%;%INSTALL_DIR%\bin
git clone --depth 1 https://github.com/agl/jbig2enc
cmake -Bbuild -DCMAKE_INSTALL_PREFIX=%INSTALL_DIR% -DCMAKE_PREFIX_PATH=%INSTALL_DIR%
cmake --build build --config Release
cmake --build build --config Release --target install
cat build/install_manifest.txt | dos2unix | xargs rm
rm -r build/*