Original post

PDFINVERTER for macOS – darken (or lighten) a PDF

PDFInverter (GUI and CLI) will create a new PDF at the specified location from a source PDF. All colors will be inverted (original shown on left):

example1
example2
example3

Unfortunately page links are not preserved, but this program will darken PDFs making them suitable for night reading.

A 2-3 page PDF will invert very quickly. However a 400 page PDF may take 3-4 minutes.

A small/simple Python script is used (instead of ImageMagick) for creating the output PDF after editing. It uses the system’s Python2 interpreter with NSImage/Quartz libs. This may cause the Python launcher to open in the Dock while the program is running.

The GUI is developed with QT bindings: example2

get and run/build yourself:
  
go get github.com/rootVIII/pdfinverter
  
command-line usage:
  
# Required
-i     input PDF file path
-o     output PDF file path

Note:  If no command line arguments are provided, the GUI version will open.
  

A notarized installer .pkg is also available in the releases page.


This project was developed on macOS Big Sur 11.0.1