Manipulate PDF document and images

PDFTK for documents

pdftk is a tool in the command line that allows you to manipulate pdf documents, such as concatenating documents or extracting pages.

General syntax

pdftk INPUT_FILES OPERATION output OUTPUT_FILES

where OPERATION corresponds to the desired manipulation on the INPUT_FILES.

Concatenation

This can be done with cat:

• pdftk doc_1.pdf doc_2.pdf doc_3.pdf cat output doc_123.pdf
• pdftk *.pdf cat output all.pdf

Extraction

This can also be done with cat:

• only page 1: pdftk doc.pdf cat 1 output doc_page_1.pdf
• a range of pages: pdftk doc.pdf cat 2-5 output doc_page_2to5.pdf
• a combination: pdftk doc.pdf cat 1-10 12 15 output doc_page_1to10_12_15.pdf
• from multiple documents: pdftk A=doc_1.pdf B=doc_2.pdf cat A1-10 B1-3 output doc_1_page_1to10_doc_2_page_1to3.pdf

PDFCROP for images

pdfcrop is also a tool in the command line, to remove margins in images saved as pdf files. A concrete example is embedding figures in LaTeX or Beamer from pdf files. Figures in pdf has the advantage of being vectorized, meaning that resizing them will not impact their quality.

• automatically remove margins: pdfcrop INPUT.pdf
• if parts are cropped/removed or margins remains: pdfcrop --hires --resolution WIDTHxHEIGHT INPUT.pdf
  use a high resolution like --resolution 1000x1000 if errors remains.
• manually set margins: pdfcrop --margins 'LEFT TOP RIGHT BOTTOM' --clip INPUT.pdf
  you can set positive or negative values to respectively increase or decrease the margins. You can also set a single value for all margins --margins VALUE.

This will process and create a new file INPUT-crop.pdf at the same location.

Convert SVG to PDF

Similarly to PDF, SVG figures are vectorized. However, embedding SVG into LaTeX or beamer can be tedious. A simple workaround is to convert the SVG figure to PDF, as there are, fortunately, a number of tools to do this from the command line:

• ImageMagick:

  sudo apt install imagemagick
  convert INPUT.svg OUTPUT.pdf
  

• rsvg-convert:

  sudo apt install librsvg2-bin
  rsvg-convert -f pdf -o OUTPUT.pdf INPUT.svg
  

• Inkscape:

  sudo apt install inkscape
  inkscape INPUT.svg --export-pdf=OUTPUT.pdf
  

Each of these tools install their own dependencies, but from my limited usage inkscape seemed to be the most convenient solution.