Jbig2.pdf.py.patch-The right way to get DPI

Yesterday, I got a comment on Jbig2

Hi Steven,
thanks for the port to windows. It works very good, produces small pdf-file sizes. Only one strange thing happens. The generate pdf files have a huge page-size. For example if I process A4-size pages (29.7×20.9cm) @400dpi tiff or png the pdf file size is 164.9×116.6 cm.
Is it possible to fix this by the python pdf.py or is jbig2.exe responible for this?

after check the last version pdf.py, I notice it uses a default DPI(600). Images has different DPI, so if you want to use pdf.py, you need always modify it, it is not a good solution.

Then I check the source code of jbig, and found in jbig2_page_info structure ,

we can get xres and yres, so we can directly use xres and yres to generated proper page size.

and here is the patch file

btw, you can also download the last version jbig2 from here.


Armin became the first user, and here is his response,

Hi Steven,
thank you very much for your quick response, and the new pdf.py
which works perfect. (I checked it with my 400dpi page scans.
the pdf page size is now of the same size as the scans)

Thank you so much,
Greetings from rainy Germany :-)


Leave a Reply