使用 imagemagick 无损旋转 PDF 文件

Question

I want to rotate a 351K PDF named 08-file.pdf using CLI tools. I've tried imagemagick :

convert 08-file.pdf -rotate 90 08-file-rotated.pdf

But the original quality:

Suffered serious degradation:

I've tried adding the -density 300x300 argument , but the outcome was a 2.5M file, nearly one order of magnitude larger than the original, which is a huge waste.

Any idea how to losslessly rotate a PDF file using imagemagick?

Answer 1

11/I always had bad results in converting/altering pdf file with imagemagik/convert (bad resolution, or huge file). Playing with options -compress -density -quality was always frustrating and a waste of time (but i am no expert).

Proposal 1: pdftk

So I would recommend pdftk (you may need to install it via apt-get install)

Try :

pdftk  08-file.pdf cat 1-endright output 08-file-rotated.pdf

For old version of pdftk (v<3) rotation was indicated only by one letter: N: 0, E: 90, S: 180, W: 270, L: -90, R: +90, D: +180. The same command was:

pdftk  08-file.pdf cat 1-endR output 08-file-rotated.pdf

From another post on this site, I have a brief an explanation of the syntax

pdftk input.pdf cat 1-endsouth output output.pdf
#     \_______/     \___/\___/        \________/
#     input file    range  |          output file
#                         direction

You can see also https://linux.die.net/man/1/pdftk

Edit 2020 :

Proposal 2: qpdf

I have found another alternative which is equivalent: qpdf , easier to remember and more powerful

see QPDF manual

#Syntax (you can rotate only some pages of the document -- see the manual --
qpdf --rotate=[+|-]angle[:page-range]

# Example
qpdf in.pdf out.pdf --rotate=+180

Answer 2

Please use -compress lossless option:

convert -rotate 90 -compress lossless 08-file.pdf 08-file-rotated.pdf

From the documentation: https://www.imagemagick.org/script/command-line-options.php#compress

Lossless refers to lossless JPEG, which is only available if the JPEG library has been patched to support it.

Another option is to use the following command:

jhead -cmd "jpegtran -progressive -perfect -rotate 270 &i > &o" Image-0001.jpeg

It will write output to a temporary file and when it succeeds it will overwrite the original file:

Cmd:jpegtran -progressive -perfect -rotate 270 "Image-0001.jpeg" > "h1xQ6q"

Modified: Image-0001.jpeg