How do I reduce the size of a pdf file that contains images?

Question

I have a pdf file that contains images and I want to reduce its size in order to upload it to a site with a size limit.

So, how can I reduce the size of a pdf file from the command-line?

Answer 1

You can use gs - GhostScript (PostScript and PDF language interpreter and previewer) as follows:

• Set pdfwrite as output device by -sDEVICE=pdfwrite
• Use the appropriate -dPDFSETTINGS.

From Documentation:

-dPDFSETTINGS=configuration
Presets the "distiller parameters" to one of four predefined settings:

• /screen selects low-resolution output similar to the Acrobat Distiller "Screen Optimized" setting.
• /ebook selects medium-resolution output similar to the Acrobat Distiller "eBook" setting.
• /printer selects output similar to the Acrobat Distiller "Print Optimized" setting.
• /prepress selects output similar to Acrobat Distiller "Prepress Optimized" setting.
• /default selects output intended to be useful across a wide variety of uses, possibly at the expense of a larger output file.

• -o option to output file which also set -dNOPAUSE and -dBATCH (see Interaction-related parameters)

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Example:

$ du -h file.pdf 
27M file.pdf

$ gs -sDEVICE=pdfwrite -dPDFSETTINGS=/ebook -q -o output.pdf file.pdf

$ du -h output.pdf 
900K    output.pdf

Here -q suppress normal startup messages, and also do the equivalent of -dQUIET which suppresses routine information comments

Answer 2

ps2pdf input.pdf output.pdf

I got the answer from ask ubuntu and it worked for me. It actually reduced 18.1Mb to 1.0Mb

Answer 3

If the PDF file consists entirely of image data;

pdftk inputFile.pdf burst
mogrify -density 300 -format jpg -quality 20 pg_*.pdf 
convert *.jpg -auto-orient outputFile.pdf

The density value can match the density of the source image (eg 300 dpi), but the jpeg quality should be lower than the source image (e.g. 20).

Answer 4

Following a pair of recipes derived from the answers of @freeman, @Pandya, and the comments of @CrisLuengo and @Phil294:

ps2pdf -dPDFSETTINGS=/ebook in.pdf out.pdf

in this case, the IMGs are reduced according to the size of output.

If your intention is to produce an output of a different size (Ex make a a4.pdf from a A2 Poster) you may provide extra options:

ps2pdf -sPAPERSIZE=a4 -dPDFFitPage -dPDFSETTINGS=/ebook a2poster.pdf a4out.pdf 

See man gs for more options.

Answer 5

You can try this :

$ time pdftk myFile.pdf output myFile__SMALLER.pdf compress
GC Warning: Repeated allocation of very large block (appr. size 16764928):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 8384512):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 11837440):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 8384512):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 33525760):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 7254016):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 34041856):
    May lead to memory leak and poor performance.
GC Warning: Repeated allocation of very large block (appr. size 33525760):
    May lead to memory leak and poor performance.

real    0m23.677s
user    0m23.142s
sys     0m0.540s
$ du myFile*.pdf
108M    myFile.pdf
74M     myFile__SMALLER.pdf

It is faster than gs but compresses upto 30% in this case for a 107.5MiB input file.