Forcing grayscale PDF to Black and White?

Question

I have a large color PDF that I can easily view greyscale in Foxit Reader:

Unfortunately various bits of text end up in ridiculously light shades of grey. Similar, but not direct, questions include:

• Displaying PDF files white on black
• Converting a PDF to black & white with ghostscript
• Convert a colored PDF into a white/black

How can I force a PDF to display only in pure black and white?

Solution

ImageMagick is free and cross-platform. This command should work:

convert <input> -threshold xx% <output>

For example:

convert original.pdf -threshold 50% new.pdf

You'll have to set the threshold to taste.

Comments

[Bryce]

It is an autocad drawing, but I don't have autocad.

[WebComer]

Personally, i do hate it. So many years - 2017, FoxItReader 8.1, the problem still not solved. Yet. And plenty-plenty non-printable ok docs... And command line converting instead of using already present checkboxes... I do hate it.

[Santosa Sandy]

Hi @Kev , would you tell me how to do that in IMDisplay.exe , please?

[Arun]

@SantosaSandy sorry I honestly never use IMDisplay.exe so I don't know whether it's possible nor, if so, how.