I am generating my PDF document (thesis) with LuaLaTeX. Almost all of my figures are made with the pgfplots package and do not exceed 40 kB. The document is 178 pages. The size of this document is 34 MB. It is too large to upload to our library server.
Even if I exclude all non-PDF images the size does not decrease much. It decreased on the size of png images I'm using.
Is there a way to reduce the quality of the document and compress it? For example: compress all figures...
Ensure that the compress settings are correct:
\typeout{pdfcompresslevel=\the\pdfcompresslevel}
\typeout{pdfobjcompresslevel=\the\pdfobjcompresslevel}
\typeout{pdfminorversion=\the\pdfminorversion}
Default for TeX Live 2014:
pdfcompresslevel=9
pdfobjcompresslevel=2
pdfminorversion=5
\pdfcompresslevel compresses streams as page descriptions.
An enabled \pdfobjcompresslevel (value 1 or 2) compresses further data structures, but requires PDF-1.5.
If you have smaller values, then the values can be set by:
\pdfcompresslevel=9
\pdfminorversion=5
\pdfobjcompresslevel=2
It can be set at the very begin of the TeX file and should be done before the first object is written to the PDF file. You can check later that no package or class has changed the values.
OpenType fonts can be much better compressed than Type 1 fonts, because the latter are stored encrypted, which does not compress very well. Since LuaTeX is already used, I assume that the fonts are already OpenType?
The program pdffonts or AR's font information can be used to check the type of the fonts.
Refer the 40KB to the source of the plots? Then the result in the PDF file can be much larger. With simple commands much output can be generated. Thus it is possible that much of the 34MB is caused by the plots.
A tool like pdftk can be used to split the PDF into single pages to look for pages with large size.
There is a wonderful script to shrink a PDF: https://github.com/pts/pdfsizeopt . I've been using it for years and can recommend it.
Regarding the question of the cause for such a large PDF: Maybe you saved different versions of your file, which only have a different file extension (*.jpg, *.png ...). For some reasen LuaLaTeX prefers the large JPG and not the small PNG.
Or -- we had that earlier -- a background process of LuaLaTeX converts your files to something different. Have a look into the log file, whether there is a hint for that? Otherwise provide an MWE and a picture.
A kind of last resort is to open the PDF in Acrobat Standard and let Acrobat shrink it. But you need the software...
pdflatexsmaller?XeLaTeXare generally much smaller.